Xeriscape Design Concepts for Large Lots Solutions to the Challenges of Landscaping On the West Bench
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The document provides a guide on xeriscape design concepts tailored for large lots in the West Bench area of Penticton, BC, addressing challenges related to water conservation and managing soil erosion. It highlights strategies such as soil analysis, suitable plant selection, and efficient irrigation practices, aiming to educate residents on sustainable landscaping practices. This manual is a compilation of information from a workshop conducted to support residents in mitigating erosion risks while enjoying the benefits of xeriscaping.
Xeriscape Design Concepts for Large Lots Solutions to the Challenges of Landscaping On the West Bench
- 1. Xeriscape Design Concepts for Large Lots Solutions to the Challenges of Landscaping on the West Bench Toni Boot and Janelle Parchomchuk December 2009
- 2. About This Publication This manual is a publication based on the Large Lot Xeriscape Design Workshop held on November 14, 2009 for the West Bench Irrigation District. It closely follows the outline of the Workshop (see Table of Contents, facing page), while keeping within the scope of the Large Lot Xeriscape Design Project Terms of Reference. It is written and presented specifically for the residents who live: (1) on the large lots of the West Bench area of Penticton, BC and (2) use water purveyed by the West Bench Irrigation District. However, anyone wishing to explore xeriscaping will find the manual beneficial, particularly if large lot sizes or highly erodible or silty soils are a concern on their property. Soil conditions similar to those of the West Bench occur in various locations within the Regional District of the Okanagan-Similkameen, the City of Penticton, and the District of Summerland. They are also known to exist in other parts of the BC Interior such as Kamloops, Princeton and Prince George. Xeriscape Design Concepts for Large Lots: Solutions to the Challenges of Landscaping on the West Bench is not simply a “How to Xeriscape” manual. It also includes information on how to manage and reduce the risks of hazardous soil erosion on the West Bench. To get the full benefit of the colour in this publication, it is best to download and save it on your computer. If you choose to print the document, use a colour printer and 8.5” x 11” paper (Letter size). To reduce paper use, print on both sides, if possible. This icon represents a particular design consideration or implementation process that can result in considerable cost-saving when converting a large, West Bench, landscaped lot to xeriscape. This icon represents information or ideas that are particularly helpful to owners of large West Bench properties. This icon represents a method to reduce erosion of West Bench soils. This icon represents a special Tip or Idea. Cover Photo: Native Plant Bed, Grasslands Nursery Page 2
- 3. Table of Contents Introduction ............................................................................................................................................ 4 Xeriscape on the West Bench ................................................................................................................. 5 1 Planning and Design................................................................................................................ 6 Planning Considerations, The Base Plan......................................................................... 6 Design Considerations ..................................................................................................... 7 Tips for Low-Maintenance Design ................................................................................... 7 2 Soil Analysis and Amendment ................................................................................................ 8 Soil Variability, Amending the Soil ................................................................................. 8 3 Practical Turf Areas................................................................................................................ 10 Conserving Resources on Your Turf Area..................................................................... 10 How to Remove Turf...................................................................................................... 11 4 Plant Selection ....................................................................................................................... 15 Grouping Plants by Water and Sun Requirements....................................................... 15 “Spread the Word — Not the Weed” ............................................................................. 16 5 Efficient Irrigation ................................................................................................................. 17 Irrigation Design, Zones ................................................................................................. 17 When to Water ............................................................................................................... 18 Watering Frequency........................................................................................................ 18 Soil Penetration .............................................................................................................. 18 Watering New Plantings ................................................................................................. 18 Irrigation Systems............................................................................................................ 21 Automatic Timers and Monitoring Weather ................................................................ 24 System Maintenance and Water Audits......................................................................... 24 6 Mulch ..................................................................................................................................... 25 Benefits of Organic Mulch ............................................................................................. 26 Using Rock Mulch .......................................................................................................... 26 Costs and Coverage ........................................................................................................ 26 Mulching Tips ................................................................................................................. 26 7 Maintenance........................................................................................................................... 27 Managing Run-off from Roofs and Driveways ..................................................................................... 28 Steps to Harvesting Rainwater................................................................................................... 28 Tips ............................................................................................................................................. 29 Driveway and Roof Runoff........................................................................................................ 29 Landscape Features to Capture, Distribute and Infiltrate Water............................................. 30 Plant List for the West Bench.......................................................................................................... 31-35 Locally Invasive or Potentially-Invasive Species.................................................................................... 35 Resources ............................................................................................................................................... 36 Bibliography ......................................................................................................................................... 38 Index .................................................................................................................................................... 39 Page 3
- 4. Introduction The hazardous soil conditions of the West Bench area of Penticton have been detailed in numerous studies since the 1960’s. The most notable of these was done in 1992 by Klohn Leonoff: West Bench/Sage Mesa Area Geological Hazards Review. The report advises that high groundwater loads from settlement have contributed to and continue to create the potential for hazardous subsurface erosion due to the high silt content of the soils. This takes the form of slumping bluffs as well as subsurface piping and can lead to a number of deleteri- ous effects, including damage to homes, roads and other utilities. The majority of the recommendations from the 1992 Klohn Leonoff report have been implemented on the West Bench and environs at the regulatory level, and are aimed at reducing groundwater loading including: • a moratorium on additional septic systems through prohibiting further subdivision of land in the area • monitoring leakage of pools and water systems. In addition to reducing slumping and erosion of the high silt content lacustrine soils on the West Bench, implementing xeriscape has a number of other positive effects including: • mitigation of climate change impacts on water supply • reduced water use by residents in anticipation of water metering • efforts to realize cost savings through reduced power consumption • reducing the rate of deterioration on water supply infrastructure and associated cost savings. The West Bench Irrigation District Board felt a timely opportunity existed to address another recommendation of the report, specifically: “Dry land landscaping is beneficial, particularly for residents living near the edge of bluffs. Irrigation water added for lawns and gardening can be detrimental to geologic stability. A process of educating all residents of the potential hazards and their associated risks, along with methods of mitigating these problems, could go a long way to reduce the occurrence of subsurface erosion caused by development.” The Large Lot Xeriscape Design Workshop, held November 14, 2009, was the first step toward education. The Workshop was attended by a cross-section of West Bench residents, and industry and government representatives. This Manual, Xeriscape Design Concepts for Large Lots: Solutions to the Challenges of Landscaping on the West Bench, is a compilation of the information, discussion, and findings of the full-day Workshop. Page 4
- 5. Xeriscape on the West Bench The West Bench Irrigation District has identified several factors that make large lot xeriscaping a strong option to consider in the West Bench area: • reduced water use minimizes the hazards associated with the erosion of silty soils • water conservation helps to mitigate the effects of climate change and development pressures • the lessened water demand will save costly upgrades to the pump house and pipe- lines resulting in the reduction of water bills • xeriscape reduces the power and water costs which will become evident when water meters are installed in the next 2-5 years. The word ‘xeriscape’ ('zir-ə-skāp, 'zer-ə-skāp) originates from the Greek word xeros, mean- ing “dry”. Definitions abound for the term but they all have one thing in common: conserv- ing water in the landscape. There are many reasons to xeriscape: • water use can be reduced by more than 50% “Dryland landscap- • reduction of erosion hazards on sensitive soils ing is beneficial, • lower water use = lower maintenance particularly for resi- • eliminates use of toxic pesticides and herbicides dents living near the • a tangible, enjoyable way to reduce your impact on edge of bluffs. our environment • low-water native selections provide food and habi- Irrigation water tat for South Okanagan birds, butterflies and bees added for lawns and • a xeriscape will survive restricted water use during gardening can be drought conditions. detrimental to Xeriscape follows seven established principles. Gener- ally, each principle builds on the one previous to it; strive to geologic stability.” achieve the full benefits of xeriscape by implementing all 1992 Klohn seven steps: Leonoff Report 1 Planning and Design 5 Irrigation 2 Soil Analysis and Amendments 6 Mulch 3 Practical Turf Areas 7 Maintenance 4 Plant Selection Page 5
- 6. 1 Planning and Design Eighty percent of the 351 rural resident lots occurring in the West Bench are .5 to .75 acres; the remaining 20% are larger. For this reason, a good plan and xeriscape design is especially critical to West Bench residents. The finished design: • can save a lot of time and money • makes it easier to budget and complete the project over several years • allows you to accurately compare estimates from landscape contractors • makes you really think about how you use your landscape…and how you could use it • will make your xeriscape materialize in an organized manner. Do your own planning, then have a landscape designer review your final plan. If your project runs two years or more, plant the trees and large shrubs first. You’ll want to enjoy the benefits of trees (for example, cooling effect, reduced greenhouse gases) as soon as possible. And, it’s much easier and less costly to move perennials and small shrubs should the need arise! Planning Considerations Here are a few things to think about when planning your xeriscape: • Site — sun/shade; wind exposure; slopes; rocky areas; drainage; moisture; traffic noise, etc. It is particularly important on the West Bench to recognize the silty soils because of their erosion hazard, low permeability, and low organic content. Also consider the site’s proximity to bluff edges, gullies and sinkholes. • Use — youngsters; out-of-doors entertaining; vegetable garden; pets; sports; outbuildings; water catchment and dispersal, etc. • View — from inside the house or from a deck; screening. • Microclimates — sun path; cold troughs; windy areas; dry or moist shade. • Grade — always ensure the ground slopes away from your house. The Base Plan After measuring the site, including elevations, draw a base plan to scale. Include: • residence, outbuildings, patios, telephone poles, lot boundaries, septic field • water flow • slopes and natural features, e.g., creeks, rock outcrops, existing vegetation • scale, North arrow, name, address Take some pictures of your site as well. Page 6
- 7. Design Considerations • Wildlife — attract (birds, butterflies, bees) or repel (deer, horses, bear)? • Zonal Planting — group plants with similar water and light needs. • Lawn — how much and where? • Hardscape — fences, patios, paths, etc. • Water feature — pond, pondless waterfall, bubbler, rain garden. • Service areas — storage shed, kennel, space for garbage cans, etc. • All season colour — evergreen trees and shrubs, ornamental grasses, bulbs, ground- covers and perennials, deciduous trees and shrubs. Think about berries, foliage and bark colour as well, not just flowering colour. • Native plants — no plant material is more adapted to our semi-arid environment than native species. • Lighting or other electrical needs. Tips for Low Maintenance Design • consider low-water lawn seed mixes, groundcovers and meadows • use evergreen trees and shrubs • use native plants and drought-tolerant plants that grow well in Bench soils • plant in the fall • use mass plantings • allow room for mature shrubs and trees • use perennials (vs. annuals), naturalizing bulbs and ornamental grasses • use organic mulch to cover bare ground between plantings Want some other ideas? Take part in a Meadowlark Festival ‘Xeriscape Garden Tour’ held every year in May. Landscaping information is widely available at public libraries and online (see bibliography). Whenever possible do it yourself, but know when to hire a professional, for example, with installation of rockwork, patios, and focal features. Recycle materials and make use of natural or existing features already on your property, for example, rocks, rock outcroppings, or native plants. Page 7
- 8. 2 Soil Analysis and Amendment The West Bench consists primarily of dry, lacustrine silts, (see map opposite page), deposited in glacial Lake Penticton during the retreat of the last phase of glaciation The soil has slow drainage, weak soil structure, and is naturally low in humus (organic matter) and nutrients. It is highly susceptible to erosion when excess water is applied. Soil Variability Not all soils in the West Bench are silty; there are areas that are quite sandy or have a high gravel content. It is important to determine the variability of the soils by digging several test holes at various locations on your lot. The City of Penticton has created a detailed map of soil variability; this map is available for viewing through the City. Regardless of the soil type, most native soils in the West Bench area lack organic matter. Residents are encouraged to create a subsurface environment that pro- motes healthy plant development with deep root growth. This will both mitigate the erosion hazards associated with soils that have a high silt content, and improve the soil structure and absorption in sandy or gravelly soils. Amending the Soil Adding organic matter is the best way to enhance moisture retention, improve soil structure and add nutrients. Amending the entire planting area may not be realistic on the large lots of the West Bench. So, it is recommended you choose plants that are adapted to the natural soil, or lightly amend just the planting hole: • dig a hole three times wider, but not deeper than, the plant root ball • use organic matter such as compost or composted manure • mix the compost into the native soil (25-30% by volume) • don’t layer and don’t plant into only the amendment • no need to amend the soil for native plants or plants that thrive in your soil type. Sources of soil amendments include ‘backyard’ compost, landfill compost and bagged or bulk compost or manures, available at local nurseries and garden centres. Page 8
- 9. Lacustrine soils with high silt content (>80%) occur through- out the bench lands of the Okanagan, especially in the Penticton area, and are highly susceptible to surface and subsurface erosion and slumping, predominantly triggered by groundwater loading. Page 9
- 10. 3 Practical Turf Areas Most lots on the West Bench consist primarily of large lawns. Although there are benefits to having a lawn in your landscape, large lawns have their drawbacks. They are “Domestic water costly to establish and maintain — on the pocketbook, on demands fluctuate your yard time, and on the environment. As you redesign throughout the year your landscape ask yourself, “How much turf do I really with maximum need?” demand being experienced Conserving Resources on Your Turf Area 1. Keep your Kentucky Bluegrass lawn, but ... during the summer, • reduce the square footage primarily due to lawn • change your watering habits (see page 23). sprinkling.” • “Gold is the New Green”: let the lawn go dormant 2005 WBID Drought (brown) in the hot summer months. Management Plan 2. Remove lawn and reseed with a low-water variety • try a blend of fescues (‘Eco-Lawn’ or ‘Enviroturf’), buffalo grass, or a buffalo grass/blue grama grass combination. • consider hydroseeding with a custom seed mix if you wish to reseed a large area • low-water alternatives can be mowed or left to grow tall, forming a meadow. Reseeding or overseeding lawn areas is less expensive than having turf installed. 3. Overseed existing lawn. • use a more drought-tolerant species (see ‘2’ above) • prepare the existing lawn by: either (1) adding 3-4 inches of topsoil, or (2) cutting the existing lawn as short as possible then use a power rake to roughen the turf and expose soil so the seed can germinate • overseed repeatedly over 2-4 years until the old lawn has been replaced. Note: This is a great option for retaining organic nutrients in your soil. 4. Eliminate turf completely (see page 11). • use an alternative groundcover (wooly thyme, kinnikinnick, creeping juniper) • Replace with other xeriscape options such as mixed planting beds or pervious hardscape. . Page 10
- 11. How to Remove Turf The prospect of removing a large amount of turf from the yard can be intimidating. However, because reducing the amount of conventional lawn is the single, most effective way to reduce water consumption, a number of ways to do so are included. In keeping with your xeriscape plan, you can convert portions of your property one year at a time. Sod Cutter A sod cutter is a gas-powered machine that is maneuvered much like a rototiller. The height (depth of the cut) of the blade is adjustable. Sod cutters can be rented from local rental centres. Work together with your neighbours. After each landowner has determined where grass will stay and where it will not, the group can hire a crew to remove five or six lawns over a weekend. If you organize a work party, the contractors can remove the turf as West Bench neighbours are loading it into a dump truck for composting at the landfill. In exchange for turf, perhaps you can make an arrangement with the Penticton Landfill for free compost to replace the organic material removed by the sod cutter. Advantages - Removes most of the existing grass roots. - Removes a thick layer of weed seeds. - Lawn can be removed quickly. Disadvantages - Very hard, heavy work. - Removes the organic, nutrient-rich layer of soil. - Must remove sod under trees by hand to avoid root damage. Credit: Toni Boot Other Comments - If you have underground irrigation, mark the sprayers to avoid damage. - Exercise care when using a sod cutter on slopes or uneven ground. - Cut the grass before you begin; remove the turf when it is not too wet. - Try cutting in a diamond pattern; the turf is very heavy. Page 11
- 12. Sheet Mulching or “Lasagna Gardening” Sheet Mulching is a layered mulch system. It is extremely inexpensive and easy to do. New plant- ings can be planted through the mulch, but if you’ve planned where you want to add vegeta- tion, it’s easier to plant before sheet mulching. A small area is left open to accommodate estab- lished plants and trees. Step 1: Prepare the site. • Mow the lawn as short as possible. • Remove healthy turf from areas where plants will be planted, allowing room for development of roots. (Turf will not biodegrade under dry conditions.) • Dig wide holes, add amendments if necessary, and plant. Water in the plant. • Lay a 1” layer of compost or manure to speed up the decaying process. • Soak the area with water. Step 2: Add a weed barrier. • Put down an organic weed barrier that is permeable to water and air. • Recycled cardboard, a thick layer of newspaper, burlap bags or old carpets of natural fiber work well. Do not use plastic. • Two or three layers may be required to achieve a ½” thickness. • Leave a generous opening for air circulation around the root crown of established trees and shrubs. • Wet down the weed barrier. Step 3: Layer mulch. • Good materials include chipped plant debris, tree prunings, leaves or straw. • The mulch layer should be 3-5” deep. Step 4: Plant. • If you did not plant in Step 1, punch a hole in the cardboard and underlying turf . Remember to cut a wide hole to accommodate root development. Page 12
- 13. Other Comments on Sheet Mulching - Do not use sheet mulching over septic drainage fields. - If your West Bench turf is healthy extra care must be taken to remove turf where plants are to be planted (Step 1), or to delay planting until the turf is thoroughly biodegraded (Step 4). - If you are installing a drip irrigation system for the transformed area, place the tubing on top of the weed barrier, and beneath the surface layer of mulch. Soil Solarization Solarization is accomplished by completely covering an area with clear or black plastic during July and August. The intense heat that builds up under the plastic kills the turf and sprouting weeds. Advantages - Easy to do. - Does not remove organic matter or nutrients from the soil. Disadvantages - Can cause an anaerobic effect, killing valuable microorganisms in the soil. - Heavy winds can displace the plastic. Anchor it with stones or wood. - Is unsightly. Photo: Lesley Field Other Comments - Mow the grass as short as possible and water well before covering with the plastic. The combination of heat and water introduces a fungus that speeds up turf decomposition. Page 13
- 14. Rototill This method takes some patience, as you need to rototill several times. Between each tilling, let the lawn sit four to six weeks to allow the grass and weeds to re-sprout. Advantages Disadvantages - Easier to maneuver than a sod - Area may be disrupted for cutter. several months. - Keeps the nutrients and organic - Cannot rototill near tree matter in the soil. roots. - Can damage the soil structure. Other Comments - Do not rototill if you have bindweed (Convulvulus arvensis, see right) in your turf, or any noxious weed that propagates by rhizomes. - Unless you are certain your underground irriga- tion system is deeper than the tines of the rototiller, do not use this method. - Mark sprinkler heads of underground irrigation before beginning (see note above). - Be prepared to spend time raking and leveling the tilled area. Spray with Herbicides If you are planning to overseed or reseed your existing turf, this method is an option to consider closely. Use a mild herbicide, such as glyphosate (trade name ‘Round-up’) or ‘Eco-Clear’, a blend of acetic and citric acids. Always follow the label directions closely. Advantages Disadvantages - Little labour involved. - Herbicides are expensive. - Kills weeds and turf. - May need several applications - Keeps the nutrients and organic to kill some perennial weeds. matter in the soil. Other Comments - Residential use of herbicides by other than certified pesticide applicators is currently being reviewed in BC. - Both recommended sprays are post-emergent, foliar products; they only work on actively growing vegetation. Page 14
- 15. 4 Plant Selection Selecting the right plant for the right location is very important. There is an exten- sive list of plants suitable for the West Bench. The list, found on pages 31-35 includes plants that thrive in silty soils, control erosion and/or are resistant to deer. They are all winter- hardy to zone 5 and grow in dry to low-water conditions. When selecting plants for your site it is also important to consider sun and wind expo- sure. Plants can also be selected for their practical purposes. For instance, shallow-rooted plants, such as grasses and certain herba- Create an ceous perennials, are good choices over septic drainage fields; like- ‘oasis in the wise taller plants can create shade or provide screening. Remember grassland’. trees are an important part of xeriscape: they provide shade and have a cooling effect on the home and the landscape. Grouping Plants by Water and Sun Requirements (Zonal Planting) Picture your lot as an ‘oasis in the grassland’: the area clos- est to your house (Zone 3) is the most lush and full. This zone includes small turf areas and vegetable gardens. Fur- ther from your house, but not on the peripheral of your property, is Zone 2 which contains low-water plants that benefit from occasional drip irrigation. Zone 1 is furthest from your house and contains only those plants that do not require supplemental irrigation, once established. This is an excellent area to consider a native plant garden or habitat restoration. As you are selecting plants, decide in which of the three zones the plant will do best, based on its needs. Zone 1 requires the least amount of watering and the least amount of mainte- nance. On the large lots of the West Bench, this zone should be the largest zone. Conversely, Zone 3, which requires the most care and watering, should be kept small and practical. Zone 1 Dry ‘Natural’ Hand water until established Zone 2 Low-Water ‘Transition’ Micro/drip irrigation Zone 3 Moderate Water ‘Oasis’ Micro/drip irrigation (except for turf area). Page 15
- 16. Purchasing plants to fill a large-lot can become very expensive. Here are some tips for obtaining plants on a low budget: • Start your own plants from seed or trade xeriscape seeds, plant divisions and cuttings with friends and neighbours. Have an annual plant trade day. • Salvage native plants (with permission) from lands scheduled for development. • Buy plants in the fall when they are usually at a discounted price. • Bulk purchase plants together with neighbours; prepare beds before buying. • Check with local nurseries to ask if they custom grow large orders. • Buy your plants in the smallest sizes possible, such as in plugs. They are less expensive and will more easily adapt to your soil conditions. • Ornamental grasses and perennials are cheaper than shrubs and trees. • Buy plants from the discount section of the nursery. • For large areas or slope stabilization, choose native plants that spread. • Plant perennials instead of annuals—you don’t have to replace them every year. “Spread the Word — Not the Weed” The Invasive Plant Council of BC states that, among other problems, invasive plants have the potential to decrease natural biodiversity and wildlife habitat, lower property values, and hinder aesthetic appeal. Simple Ways Gardeners Can Help: • Choose plants wisely. Be suspicious of plants promoted as “fast spreaders” or “vigorous self-seeders.” • Do not purchase or grow invasive or legislated noxious weed seeds or plants. • Dispose of invasives carefully: don’t ‘recycle’ garden debris or compost. Properly dispose in trash bags for a local disposal facility/incineration, or by drying out any material to kill remaining vegetative parts. • Avoid letting invasive plants fruit or set seed, as birds and animals can spread the plants to other areas. Remove flowers, seedpods, and berries of invasive plants. • Avoid using exotic wildflower seed mixes. • Avoid picking plants from roadsides, gravel pits or other disturbed areas. • Discourage propagation of invasive species by friends and neighbours. • Limit soil disturbance and cover bare soil on your property. • Get involved with local efforts to control invasive plants. • See page 35 for a list of locally invasive or potentially-invasive weeds. • RDOS and the Invasive Council of BC have additional information and pictures. (See Resources, page 36.) Page 16
- 17. 5 Efficient Irrigation West Bench Irrigation District’s Drought Management Plan states that during winter months, typical water demands are in the order of 490 m3 per day. In summer, the irrigation demand “… increased increases twenty-fold to 10,000 m3 per day. The maximum infiltration raises summer demand is primarily due to lawn sprinkling. By simply the water table converting to efficient irrigation practices landowners can see a so that a dramatic reduction in water use. Excessive irrigation not only wastes a valuable resource, it smaller trigger- can lead to soil saturation or groundwater loading. This addi- ing event, such tional water can be enough to increase the likelihood of pipe and as higher than sinkhole developments or a major erosion event such as land- average rainfall, slide. is required to induce a Start with a Good Irrigation Design landslide.” An irrigation system must be well designed and installed by 1992 Klohn a licensed irrigator in order to be efficient and cost-effective. It is Leonoff Report important to review the West Bench irrigation bylaws and to ensure that proper backflow prevention devices, valves and con- nections are installed. The South Okanagan has many professionals certified by the Irriga- tion Industry Association of BC to help you design and install an irrigation system that works for you. Start with a xeriscape plan, then hire a professional to cap unusable or unnecessary portions of the underground system, and install a controller that allows for proper water usage. From there, it is relatively simple for the homeowner to refit sprinklers to micro or drip systems for xeriscape zones. For best results, hire a certified irrigation professional who understands how to irrigate a xeriscape. Zones Group your plants according to their watering requirements (see pg. 15). Not only will this save water, it will prevent the need for complex or costly irrigation systems. Page 17
- 18. When to Water You should only water your landscape when necessary. Keep an eye on your plants and soil moisture to know when to water. This will vary depending on the current weather, recent rainfall, time of year, and your specific soil types. Generally, the leaves of shrubs and perennials will begin to droop, and lawn grass will leave footprints when dry. If the top inch of soil next to a plant feels dry when you wiggle your finger into it, this is another sign that water is needed. You can also use a shovel or a soil probe to determine how dry the soil is. It is best to water when the weather is cool, dark, humid and windless. At night or early in the morning before sunrise are optimal times. Irrigation during these times also helps to reduce interference with daytime household water and energy demand. Watering Frequency For xeriscape plants, it is important to water deeply and infrequently. Soaking the soil to the bottom of the root-zone encourages roots to grow into deeper soil, instead of spread- ing into drier surface soil. Wait until the soil partially dries out before watering again. Watering Depth and Rate Soil Type Penetration depth of 1” of Infiltration rate of water water (inches) (inches /hr) 1 Clay 4-5 /10 to ¼ Silt/loam 6-8 ¼ to ¾ Sand 12 -14 1-2 Soil Penetration For typical West Bench silty soils, one inch of water penetrates 6-10 inches. Silty soils should be watered at a rate of approx ½ inch per hour. More than this may lead to surface run-off and can lead to serious erosion problems Visible puddles are a sign that the watering rate is too high; water pressure should be turned down, or watering should be spread over a series of cycles. Run-off monitoring is especially important on slopes. Page 18
- 19. Watering New Plantings New plantings must be watered regularly until deep roots are established — the first year for shrubs, and 2-3 years for trees. Water deeply, to the bottom of the root zone. Irrigation Systems Irrigation systems can range from simply hand-watering your plants with a watering can or hose nozzle, to complicated underground systems with timers and soil sensors. The most efficient irrigation systems use nozzles that apply water directly to the soil in the root zone of the plants needing water, with the least loss of water by evaporation. Low-flow systems, such as “micro” or “drip” irrigation are very efficient. Micro Irrigation Micro irrigation is highly recommended for xeriscape landscapes. This system includes a flexible supply tube that lays on the soil surface, with individual emitters that supply each plant. Landowners interested in this system can consult with local irrigation suppliers for information before starting a project. Benefits of Micro Irrigation • existing underground irrigation can easily be converted to drip or micro irrigation • very inexpensive, and extremely adaptable • less water is lost to evaporation; this is especially important for windy areas • emitters can be adjusted to the water requirements of each plant as it grows • do-it-yourself landowners can easily purchase and install these systems • irrigation timers and sensors can be included, but are not required • well-suited system for plant beds in the low- and moderate-water zones • the system is above ground, therefore leaks can be easily detected. Page 19
- 20. Before After After Designer: Toni Boot Photos: Kevin Dunn Page 20
- 21. Designer: Toni Boot April June September Before Designer: Toni Boot Designer: Toni Boot After Photos: Toni Boot Page 21
- 22. Basic Irrigation Schedule for Drip Irrigation Systems in West Bench Plant Type Root Avg. April, May, Oct June, Sept July, Aug depth water Hours Days/ Hours Days/ Hours Days / (in.) needs week week week Vegetables 4-8 Mod 2 1 3 2 4 3 and annuals Perennials Every Low 1.5 2.5 1 2.5 2 2 wks. 8-12 Mod 2 1 3 2 4 3 Small shrubs Every Low 3 4 1 4 2 3-5 ft 2 wks. 12-24 Mod 4 1 5 2 6 3 Large shrubs Every or small trees Low 5 5 1 5 2 18-30 2 wks. 5-10 ft Mod 6 1 7 2 8 3 Mature trees Every Low 5 6 1 6 2 10-25+ ft 2 wks. 24-36 Mod 6 1 8 2 10 3 • These are general guidelines. Needs vary depending on weather, flow rates and soil. • Figures based on ½ gph (gallons per hour) for perennials, 1 gph on shrubs, 3 gph on large shrubs and 6 gph on mature trees. • For automated systems, spread your daily allotment over 3 cycles during the day. Watering By Hand For many garden areas, complex irrigation is not necessary, and hand-watering or moving sprinklers will suffice. Plants in the dry or natural zone should not require regular irrigation once they are established. Simply handwater these plants during the first year of growth, then water only when necessary during extremely dry conditions in following years. Smaller gardens, plants close to the house, or feature trees can also be watered by hand. Page 22
- 23. Hand or Sprinkler Watering for Larger, Mature Plants Plant Type Root Avg. April, May, Oct June, Sept July, Aug depth water Gallons Times Gallons Times Gallons Times (in.) needs per per per month month month Small shrubs Low 5 0-1 5-10 1-2 5-10 1-2 3-5 ft 12-24 Mod 5-15 1 10-20 2 10-20 2-3 Large Low 20-30 0-1 20-40 1-2 20-50 1-2 shrubs/small 18-30 Mod 30-60 1 30-60 2 30-60 2-3 trees 5-10 ft Mature trees Low 100-150 0-1 100-150 1-2 100-150 1-2 10-25 ft 24-36 Mod 150-200 1 150-200 2 150-200 2-3 • These are general guidelines. Needs vary depending on weather, flow rates and soil. • Determine the flow rate or your sprinkler or hose by submerging the sprinkler or nozzle in a large bucket of known volume. Time how long it takes to fill the bucket to determine your flow rate in gallons per minute or gallons per hour. Lawn Irrigation Conventional sprinklers or underground irrigation are the normal systems for lawn irrigation. There are also nozzles for micro irrigation systems suitable for small turf areas. Application Rate Lawns benefit from approximately 1” of water for every irrigation. To determine how many minutes you need to turn on your sprinklers: • place straight-sided containers, such as tuna cans, around your lawn • turn on the water for 15 minutes • determine the average depth of water, in inches, in the containers • calculate your flow rate in inches/minute: (avg. depth of water divided by 15 min.) • to obtain 1 inch of irrigation, divide the number “1” by your flow rate. This is how long you need to turn on your sprinklers to saturate the lawn to root depth. Pooling water indicates the application rate is higher than the infiltration rate; adjust your system accordingly. The lawn should then be allowed to dry out a little between watering. Generally, once the grass starts to lay flat, or footprints are left in the lawn when you walk across it, then it is time to irrigate again. Page 23
- 24. Recommended Watering Frequency for West Bench Lawns Grass Type Avg. Root Water Number of irrigations per month Depth Needs 1-inch of water per irrigation April, May, Oct June, Sept July, Aug Buffalo grass 6-8” Very low 0-1 1 1-2 Fescue (Ecolawn or 6-10” Low 1 2 2-3 Enviroturf) Conventional 3-6” Moderate 1-2 2-4 3-4 Bluegrass lawn • These are general guidelines. Needs vary depending on weather, flow rates and soil. Automatic Timers and Monitoring Weather Irrigation systems with automatic timers can help to reduce water use, but only if they are adjusted regularly to prevent overwatering. Remember these systems are only as efficient as the person who sets the timer! It is important to monitor your landscape and the weather regularly so that you can reduce irrigation when there is sufficient rainfall. Soil moisture sensors and shut-off devices can be installed to do this automatically. Visit www.farmzone.ca and www.irrigationbc.ca for up-to-date, local weather information. System Maintenance and Water Audits Your irrigation system should be monitored regularly to ensure proper functioning and application rate. A yearly irrigation water audit by yourself or a contractor includes: • checking for leaks and making sure valves open and close properly • ensuring sprinklers are upright and the arc is correct • clearing or changing blocked nozzles • ensuring water is not falling on pathways, patios or driveways • application rate is appropriate • timers and sensors are functioning and set properly Additional Thoughts in Reducing Irrigation in the West Bench • have water purveyor set up automatic systems • install dole valves and flow restrictors at each property • stagger the water fees (once meters are installed), based on water usage. Page 24
- 25. Mulch West Bench lacustrine silt is low in organic matter. When mulch is applied to this type of soil, the increase of organic material: (1) enhances water absorption, and (2) slows the rate of infiltration. Both these benefits reduce the risk of erosion. Mulching is one of the best things you can do to ensure the health of your plants. There are two general types of mulch: organic and inorganic. Organic mulches consist of plant materials, such as: shredded bark, wood chips, chipper debris, sawdust, wood shavings, dry grass clippings, pine needles, evergreen boughs, peat moss, straw, compost, newspaper, shredded paper, leaves, and leaf mold. Inorganic mulches consist of non-living materials, such as: plastic, woven fabrics, pea gravel, river rock, crushed stone, and shale. Benefits of Organic Mulch • limits reflectivity, keeping plants cooler and resulting in less evaporation • absorbs and retains water around root zones • protects and insulates soil from freezing in winter • controls erosion by slowing down rainwater • reduces the loss of bare topsoil to wind • safeguards against soil compaction and crusting • builds soil, improving organic content and nutrients • reduces weed growth and seed germination • becomes a design element, giving the landscape a ‘finished’ look • some mulches help acidify alkaline soils, such as coffee grounds, evergreens, pine needles, and sawdust. Page 25
- 26. Inorganic Mulch Inorganic mulches are long lasting and are good for high traffic areas such as pathways. However, they can be hard to clean, expensive and difficult to weed. Keep in mind that rock mulch, particularly in our hot Okanagan summers, can create an additional stress on plants because of its tendency to both absorb and reflect heat, increas- ing temperatures around your plants, your home and your neighborhood. The increased heat results in a higher evapotranspiration rate, which leads to higher water demands. If you plan on installing rock mulch, you are recommended to keep these features small. Costs and Coverage Mulching is one • Recommended depth of mulch is 2 inches for fine of the best mulch to 4 inches for rough mulch. things you can • One cubic yard covers 108 sq. ft. in 3 inches of mulch. do to reduce soil • The cost of organic bark mulch ranges from $25 to $60 erosion. per yard ($0.25 – 0.60/sq. ft). Mulch can be a major expense in creating new landscapes. However, it is possible to obtain some mulches for free. Some free materials include grass clippings, pine needles, leaves, chipper debris, cardboard and newspaper. Mulching Tips • The best time to add mulch is just after planting. Top-up existing mulch in the fall. • Locate flammable mulches such as pine needles, straw and evergreen boughs away from wooden walls and fences. Once organic mulches have aged and flattened down, they are much less flammable. • Do not bury stems or trunks of trees, shrubs, and woody perennials; this avoids pest or fungal problems. • Mulch containing strips of bark or different size chunks tends to knit together better to withstand wind. • Plastic landscape fabric under organic mulch is not recommended. Plastic prevents water infiltration and weeds will eventually grow through this layer. If troublesome weeds occur in this area, consider sheet mulching. • It is always best to cover bare soil with mulch, even if you are not ready to plant. This will save weeding time. • Extremely dry soil plants such as cacti, succulents, and artemesias are sometimes better left without mulch. Page 26
- 27. 7 Maintenance Large West Bench properties can be time-consuming and costly to manage. Although every landscape requires some maintenance the advantage of xeriscape is that much less time, money and resources need to be expended to keep your landscape beautiful and healthy. Irrigation • Perform watering system audit. See page 24. • Monitor for signs of erosion caused by irrigation leaks or run-off. • By overwatering your landscape, plants stay healthy and require less care. Lawn Care • Fertilizing a low-water lawn should only be done once annually, in the spring. Lightly topdress your lawn with compost or a nutrient-rich soil. • Overwatering and/or overfertilizing conventional lawns necessitates more frequent mowing, dethatching and aerating. Reducing both cuts down on your maintenance time. • A healthy lawn is naturally more resistant to weed growth. Weeding • Stay on top of weeding. This task is much reduced when mulch has been applied. Pruning • Prune out dead, diseased and damaged limbs. • Trees should be pruned when they are dormant. • Proper watering and fertilization practices, and allowing room for mature species, can virtually eliminate the need to prune. Fertilizing • For the most part, xeriscape plants do not require the application of fertilizer, particularly if you’ve amended the soil. • Do not fertilize native plants. Mulching Photo: Grasslands Nursery • Top up mulch when necessary. Page 27
- 28. Managing and Using Rainwater Runoff Rainstorms can be few and far between in the arid Okanagan Valley. However, when they do arrive, the rapid flow of surface waters can cause serious erosion problems in the West Bench area such as gully erosion, underground piping, sinkhole formation, and landslides. Sudden rainfall is often viewed as a hazard, but with a few simple preparations, rainwater can be turned into a valuable resource for landscape irrigation. Steps to Harvesting Rainwater Begin with long and thoughtful observation. • Observe where the water flows, where it collects, where it drains away, and where it drains from. This informs you of your resources and challenges. Build on what is working and change what isn’t. Start at the top of your property or house, and work your way down. • It is easier to harvest water at the top where it is more manageable. Then use the free power of gravity to distribute harvested water to areas down slope. Start small and simple. • Small, simple systems of an appropriate scale are easier to create and maintain than complex, extensive systems. Start with a rain barrel off one downspout or create a berm around a large tree where runoff occurs. Slow, spread, and infiltrate the flow of water. • A zigzag pattern calms the flow of water to reduce destructive erosion and increases the time and distance the water flows. This will improve infiltration into the soil from the high point to the low point. For example, creating a system of small berms or terraces on steep slopes helps to slow flow of water. Always plan an overflow route and manage that overflow as a resource. • You can’t turn off the rain once your water-harvesting earthworks and cisterns are filled up, so always be prepared for overflow into the surrounding landscape. Create a living sponge. • Maximize planting of appropriate vegetative groundcover and spread organic mulch over the surface of the soil to create a “living sponge”. As roots expand and soil life increases, the soil’s ability to infiltrate and hold water steadily improves. Continually reassess your system. • Monitor the success and failures of your rainwater systems. If necessary, make changes using the above steps to guide you. Page 28
- 29. Tips • Do not infiltrate water within 10 feet of a building foundation. • Always check for underground utility lines before digging. • Harvest water into the moderate-water or oasis zone, where the plants need it most. • Make sure land slopes away from all buildings. • Don’t move large quantities of soil; instead, work with the existing landscape forms. • Direct downspouts or rain barrel overflows onto high points, so that gravity can be used to distribute the water throughout the site via berms and basins. Driveway Runoff • Reduce the amount of impervious, paved surface on your property. • Slope pavement to drain into vegetation alongside driveway. • Cut grooves or create small speed bumps to divert water towards plantings. • Use small berms alongside driveway to catch and hold water around plants. • Install drain tile or a French drain at the bottom of a long slope in the driveway to divert water to the sides rather than onto the main road. • Consider installing porous surfaces for driveways and paths such as gravel, recycled asphalt, porous asphalt, open-jointed blocks or turf blocks. • Reduce the driveway to two narrow strips for vehicle tires. Roof Runoff • Install rain barrels at the bottom of downspouts to hold water for irrigation on dry days. Be sure to install an overflow route for water. • If downspouts empty onto steep, erodible slopes, install a rock spillway (dry creek bed) or pipe to carry water to your landscape. • Install rain chains instead of downspouts. Illustrations: Joe Marshall Page 29
- 30. • Use a perforated pipe on the end of downspouts to distribute water away from the house and towards plantings. • Install 3-4 pop-up drains per downspout, which distribute roof runoff onto your landscape. • Install a green roof to absorb and slow down rainfall while moderating the tempera- ture of your home. Landscape Features to Capture, Distribute, and Infiltrate Rainwater Berms and Basins A system of small berms and basins, also known as ‘ditch and swale’, can be used on moderate slopes to slow, disperse and allow water to infiltrate the soil. A berm generally fol- lows a contour line of a slope, or forms a boomerang shape to hold water around a specific plant. A basin consists of a depression in the ground that catches water and allows it to infiltrate the soil. Basins usually contain deep-rooted plants to soak up the rainwater, essentially functioning as a ‘rain garden’. Terraces A terrace is a flat shelf of soil built parallel to the contour of a slope, creating flat planting areas. These are typically used for smaller gardens on steep slopes. Spillways Spillways carry water from down- spouts or overflow areas towards collection basins. Spillways should be lined with plastic and artfully covered with rock to form an attractive dry creek bed, thus adding a design element to your landscape. French Drain A French drain is a plastic-lined basin or trench filled with angular gravel. This allows water to infiltrate quickly, while creating a stable surface on which to walk. French drains can be used to carry water away from non-porous surfaces to catch basins surrounding shrubs and trees. Illustrations: Joe Marshall Page 30
- 31. = Dry = Low-Water SS = Silty Soils EC = Erosion X = Deer PLANT LIST Note: “x” in a column means suitable PLANT NAME SS EC X PLANT NAME SS EC X NATIVE GRASSES NATIVE PERENNIALS Great Basin Wild Rye Snow Buckwheat x x x x x x Elymus cinereus Eriogonum niveum Idaho Fescue Brown-eyed Susan x x x x x Festuca idahoensis Gaillardia aristata Needle and Thread Grass x x x x Hesperostipa comata Prairie Smoke Geum triflorum Junegrass Golden Aster x x Koeleria macrantha Heterotheca villosa Bluebunch Wheatgrass Round-leaved Alumroot x x x x x Pseudoroegnaria spicatum Heuchera cylindrica Sandberg's Bluegrass Bitterroot Lewisia rediviva x x x x Poa secunda Blue Flax Linum perenne x x NATIVE PERENNIALS Silky Lupine Lupinus sericeus x x Yarrow Achillea millefolium x x x Nodding Onion Shrubby Penstemon x x x Allium cernuum Penstemon fruticosus Pearly Everlasting NATIVE SHRUBS x x Anaphalis margaritacea Saskatoon x x x Kinnikinnick Amelanchier alnifolia x x x Arctostaphylos uva-ursi Big Sagebrush x x x x x x x x Artemisia tridentata Pasture Sage Artemisia frigida Red Stemmed Ceanothus Western Mugwort x x x x x x Ceanothus sanguineus Artemisia lucoviciana Snowbrush Showy Milkweed x x x x x Ceanothus velutinus Asclepias speciosa Rabbitbrush Tufted White Prairie Aster x x x x x x Chrysothamnus nauseosus Aster ericoides Wolf Willow Arrow-leaved Balsamroot x x x x x Eleagnus commutata Balsamorhiza sagittata Ocean Spray Sulphur Flowered Buckwheat x x x x Holodiscus discolor Eriogonum umbellatum Common Juniper Parsnip-flowered Buckwheat x x x x x Juniperus communis Eriogonum heracleoides Page 31
- 32. PLANT NAME SS EC X PLANT NAME SS EC X NATIVE SHRUBS XERISCAPE BULBS Oregon Grape Holly Prairie Crocus/Pasqueflower x x x x x Mahonia aquifolium Heterotheca villosa Mock Orange Scilla Scilla siberica x x x x x x Philadelphus lewisii Tulip Tulipa x Shrubby Cinquefoil x x Potentilla fruticosa XERISCAPE VINES Antelope Brush Jackmanii Clematis x x x x Purshia tridentata Clematis jackmanii Smooth Sumac Rhus glabra x x White Clematis x x Waxy Currant Ribes cereum x x x Clematis ligusticifolia Prairie Rose Rosa woodsii x x x x Golden Clematis x x Blue Elderberry Clematis tangutica x x x x x Sambucus caerulea Grape Vitis x x x Soopalallie x x x x XERISCAPE GRASSES Shepherdia canadensis Snowberry Big Bluestem x x x x x x Symphoricarpos albus Andropogon gerardii Bulbous Oat Grass NATIVE TREES x x Arrhenatherum bulbosum Douglas Maple Acer glabrum x x x Blue Grama Grass x x x Rocky Mountain Juniper Bouteloua gracilis Juniperus scopulorum x x x ‘Karl Foerster’ Feather Reed Ponderosa Pine Grass x x x x x Pinus ponderosa Calamagrostis x acutiflora ‘Karl’ Chokecherry Foerster’ x x Prunus virginiana XERISCAPE GRASSES Douglas Fir Northern Sea Oats x x x x Pseudotsuga menziesii Chasmanthium latifolium XERISCAPE BULBS Fescue Festuca x x x x Crocus Crocus x x x Blue Oat Grass x x x Helictotrichon sempervirens Snowdrop Galanthus Blue Hair Grass x x x x Grape Hyacinth Muscari Koeleria glauca x x x Maiden Grass Miscanthus x x x Daffodil Narcissus Page 32
- 33. PLANT NAME SS EC X PLANT NAME SS EC X XERISCAPE GRASSES XERISCAPE PERENNIALS Switch Grass Basket of Gold x x Panicum virgatum Aurinia saxatilis Perennial Fountain Grass False Indigo x x x x Pennisetum alopecuroides Baptisia australis Hardy Pampas Grass Poppy Mallow/Winecup x x Saccharum ravannae Callirhoe involucrata Little Bluestem x x x Bellflower Campanula Schizachyrium scoparium Cupid’s Dart Autumn Moor Grass x x x Catanache caerulea Sesleria autumnalis Blue Leadwort Prairie Dropseed x x x x x x Ceratostigma plumbagnoides Sporobolus heterolepis Large-flowered Coreopsis Mexican Feather Grass x x x x x x Coreopsis grandiflora Stipa tenuissima ‘Zagreb’ Threadleaf Tickseed XERISCAPE PERENNIALS x x x Coreopsis verticillata ‘Zagreb’ Hyssop Agastache x x Hardy Iceplant Delosperma x Hollyhock Alcea rosea x x x x x x x Pinks Dianthus ‘Mountain Gold’ Alyssum x Dragon’s Head Dracocephalum x Alyssum montanum ‘Mtn. Gold’ Mt. Atlas Daisy Purple Coneflower x x x Anacyclus depressus Echinacea purpurea Daisy Erigeron species x Windflower Anemone sylvestris x x x Blanket Flower (variety) Pussytoes Antennaria x x x Gaillardia grandiflora Thrift Armeria maritima x x x Daylily Hemerocallis Sage varieties Artemisia x x x x Candytuft Iberis semervirens Aster Aster x x x x x Iris Iris Hardy Gazania x Torch Lily Kniphofia x x x Gazania linearis Cranesbill Geranium x x x x x English Lavender x x Rock Rose Lavandula angustifolia x x Shasta Daisy Helianthemum numularium x x Maximillian Sunflower Leucanthemum x superbum x Dotted Gayfeather Helianthus maximillianii x x x Liatris spicata Page 33
- 34. PLANT NAME SS EC X PLANT NAME SS EC X XERISCAPE PERENNIALS XERISCAPE PERENNIALS x x x Apache Plume x Catmint Nepeta Ozarks Sundrop x Fallugia paradoxa Oenothera macrocarpa Forsythia Forsythia x x x x Penstemon (most) Broom Genista x x x Penstemon Juniper Juniperus x x Russian Sage x x Honeysuckle (shrub varieties) x Perovskia atriplifolia Fleeceflower Persicaria affinis x x Lonicera Ninebark Phlox (some species) x x x Physocarpos opulifolius Phlox subulata Rosemary x Mugho Pine Pinus mugo x x x x Rosemarius officinalis Staghorn Sumac Rhus typhina x Gloriosa Daisy Rudbeckia hirta x x Currant/Gooseberry Ribes x x Sage (many species) Salvia* x x x x Red Leaf Rose Rosa rubrifolia x x Alpine Skullcap x x x Scutellaria alpina Rugosa Rose Rosa rugosa Stonecrops Sedums x x Dwarf Arctic Willow x x x Hen and Chicks Sempervivum x Salix purpurea ‘Nana’ Lavender Cotton x x Thyme Thymus x x Santolina chamaecyparissus Wooly Veronica Bridal Wreath Spirea x x x x x x Veronica pectinata Spirea x vanhoutii ‘Golden Sword’ Yucca Lilac Syringa x x x x x x x Yucca filamentosa ‘G. Sword’ Soapweed Yucca glauca x x Weigela Weigela florida x x x XERISCAPE TREES XERISCAPE SHRUBS Japanese Barberry x x x Maple (some varieties) Acer* x x x Berberis thunbergii Bluebeard/Blue Mist Spirea x Western Redbud x x x Caryopteris x clandonensis Cercis occidentalis Smokebush Cotinus x x ‘Paul’s Scarlet’ Hawthorn x x x Crataegus oxycantha Cotoneaster Cotoneaster x x x ‘Paul’s Scarlet’ Green Ash x x x x Euonymus (some varieties) x x Fraxinus pennslvanica Euonymus* Page 34
- 35. PLANT NAME SS EC X Potentially- Locally Invasive or Potentially- Invasive Species XERISCAPE TREES Baby's Breath (Gypsophila paniculata) Maidenhair Tree Bachelor's Button (Centaurea cyanus) x x Ginkgo biloba Black Locust (Robinia pseudoacacia) Honey Locust Gleditsia x x Butterfly Bush (Buddleia davidii) Golden Raintree Canada Thistle (Cirsium arvense) x Cherry Laurel (Prunus laurocerasus) Koelreuteria paniculata ‘Colorado Blue Spruce Common European Hawthorn (Crataegus monogyna) x x Common Fennel (Foeniculum vulgare) Picea pungens ‘Glauca’ Common Periwinkle (Vinca minor) London Plane Tree x Common Tansy (Tanacetum vulgare) Platanus x acerfolia Dalmatian Toadflax (Linaria genistifolia Gambel Oak Quercus gambelii x spp dalmatica) Greenspire Linden English Ivy (Hedera helix) x x x Tilia cordata European Mountain Ash (Sorbus aucuparia) Wayfaring Tree Hawkweeds (Hieracium spp.) x x x x Herb Robert (Geranium robertianum) Viburnum lantana Hoary Alyssum (Berteroa incana) Hound's-tongue (Cynoglossum officinale) Invasive Knotweeds (Fallopia or Polygonum spp.) Knapweeds (Centaurea spp.) Leafy Spurge (Euphorbia esula) Old Man's Beard (Clematis vitalba) Oxeye Daisy (Chrysanthemun leucanthemum) Puncturevine (Tribulus terrestris) Purple Deadnettle (Lamium amplexicaule) Purple Loosestrife (Lythrum salicaria) Reed Canarygrass (Phalaris arundinacea var. picta) Rush Skeletonweed (Chondrilla juncea) Russian Olive, Oleaster (Elaeagnus angustifolia) Scotch Broom (Cytisus scoparius) Sea Buckthorn (Hippophae rhamnoides) Siberian Elm (Ulmus pumila) Silver lace vine (Polyganum aubertii) Sulphur Cinquefoil (Potentilla recta) Tamarisk, Saltcedar (Tamarix ramosissima) Tree of Heaven (Ailanthus altissima) Velvetleaf (Abutilon theophrasti) Wild four o'clock (Mirabilis nyctaginea) Yellow or False Lamium (Lamium galeobdolon) Photo: Grasslands Nursery Yellow Starthistle (Centaurea solstitialis) Page 35
- 36. Resources (also see Bibliography) Bennett, Jennifer. Dryland Gardening:Plants That Survive and Thrive in Tough Conditions. Richmond Hill, On. Firefly Books Ltd. © 2005. Bonnemaison, Tamara. Native Plant Landscaping for the South-Okanagan Similkameen. Osoyoos Desert Society, Osoyoos BC. 2008. Dunnett, Nigel and N. Kinsgsbury. Planting Green Roofs and Living Walls. Timber Press Inc. Portland, Oregon. © 2008 Ellefson, Connie, T.Stephens, D. Welsh. Xeriscape Gardening: Water Conservation For The American Landscape. MacMillan Publishing Company, © 1992. Hansen, Juergen and Jacquie Tapping. Gardening in the Okanagan. Okanagan Past and Present Society 4th edition, Summerland. © 1995 Lang, Susan. Garden Watering Systems. Sunset Publishing Corp., CA, © 1999 Rummary, Mark. The Dry Garden: A Practical Guide to Planning and Planting. Sterling Publish- ing, New York. © 1995 Soderstrom, Neil. Deer Resistant Landscaping. Rodale Inc. New York. © 2008 Springer, Lauren. Waterwise Gardens. Prentice Hall General Reference. 1994 Taylor, Jane. Drought Tolerant Plants: Waterwise Gardening for Every Climate. Prentice Hall General Reference, New York. © 1993 Taylor's Guide to Water-Saving Gardening. Boston: H. Miflin. 1990. Weinstein, Gayle. Ortho’s All About Dry Climate Gardening. Meridith Books, Des Moines, IL. © 2004 Xeriscape Color Guide: 100 Water-wise Plants for Gardens and Landscapes. Ed., David Winger, Denver, CO. Fulcrum Pub. 1998. Page 36
- 37. Sampling of Xeriscape Websites Okanagan Xeriscape Association http://okanaganxeriscape.org Summerland Ornamental Gardens http://www.summerlandornamentalgardens.org/xeriscape Xeriscape Colorado http://coloradowaterwise.org Bluestem Nursery http://www.bluestem.ca Wildflower Farm http://www.wildflowerfarm.com Irrigation and Water Conservation Websites Farmzone http://www.farmzone.com Irrigation Industry Association of BC http://www.irrigationbc.com Landscape Watering Guide, Arizona http://www.wateruseitwisely.com/region/arizona/100- ways-to-conserve/outdoor-tips/landscape-watering-guide.php NDS Water drainage equipment and information. http://www.ndspro.com City of Penticton Water Talk Newsletter http://www.penticton.ca/city/public_works/water/default.asp Invasive Plant Websites Regional District Okanagan-Similkameen http://www.rdos.bc.ca Invasive Plant Council of BC http://www.invasiveplantcouncilbc.ca Xeriscape Designers Grasslands Nursery, Toni Boot, 250-494-4617 Eva Durance, 250-492-0158 Waterwise Landscape Design, Lisa Masini, 250-862-1931 Xeriscape and Native Plant Selection Grasslands Nursery, 3615 Gartrell Road, Summerland, BC, 250-494-4617 Sagebrush Nursery, 93rd St. #38084, Oliver, BC, 250-498-8898 Xeriscape Landscape Installers Grasslands Nursery, Steve Burritt, 250-494-4617 Summerland Senior Services, Craig Whitehouse, 250-494-8333 Certified Irrigation Contractors Emerald Irrigation, Aran Boyle, 250-490-9002 Grasslands Nursery, Steve Burritt, 250-494-4617 Page 37
- 38. Bibliography Boot, Toni. Xeriscape Seminar Series. Grasslands Nursery, Summerland BC. C.R. Elevitch and K.M. Wilkinson. Sheet Mulching: Greater Plant and Soil Health for Less Work, Permanent Agriculture Resources. Drip Watering Made Easy. 7th ed. Raindrip, Inc. Fresno, CA. 2007. Durance, Eva. Cultivating the Wild: Gardening with Native Plants of British Columbia’s Southern Interior and Eastern Washington. Nature Guides BC. © 2009. Ellefson, Connie and D. Winger. Xeriscape Colorado. Westcliffe Publishers. 2004. Geoff Hall. Sheet Mulch. Sentient Landscape, Inc. Lancaster, Brad. Rainwater Harvesting For Drylands and Beyond. Rainsource Press, Tuscon, AZ © 2008. Landscape Watering Guide. Water – Use it Wisely. Arizona. http://www.wateruseitwisely.com/region/arizona/100-ways-to-conserve/outdoor-tips/ landscape-watering-guide.php Pittenger, Dennis R. When and How to Amend Landscape Soils. University of California Cooperative Extension, Southern Region. Steele, Gwen and L. Masini. “Gardening with Nature”. 2009. Okanagan Xeriscape Association. http://okanaganxeriscape.org Weinsten, Gayle. Xeriscape Handbook: A How-to Guide to Natural, Resource-Wise Gardening. Golden, CO. Fulcrum Pub. 1999. West Bench/Sage Mesa Area Geological Hazards Review. Klohn, Leonoff Ltd., 1992. Williams, Sara. Creating the Prairie Xeriscape: Low-Maintenance, Water-Efficient Gardening. University Extension Press, University of Saskatchewan. © 1997. Page 38
- 39. INDEX A L soils about this publication, 2 lacustrine silts or soils, 4, 8, 25 amendment and sources, 8 how to print, 2 map, 9 analysis, 8 icons, 2 lasagna gardening, 12-13 of the West Bench, 8 amending and analyzing soil, 8 lawns variability, 8 B conserving resources, 10 spillways, 30 berms and basins, 30 M T bibliography, 38 maintenance of xeriscape, 27 terraces, 30 C fertilizing, 27 turf compost, 8, 25 irrigation, 27 benefits vs. drawbacks, 10 E lawn care, 27 eliminating, 10, 11-14 erosion, 2, 4 mulching, 27 irrigation costs, minimizing, 10 amending soil to reduce, 8 pruning, 27 overseeding, 10 and irrigation, 17 weeding, 27 practical turf areas, 9 hazards 2, 4, 17 micro irrigation, 19 removing, 11 maintenance to monitor, 27 mulch, 25 turf removal methods mulching to reduce, 25 cost estimates, 26 herbicidal spraying, 14 plant selection, 15, 31-35 organic vs. inorganic, 25 rototilling, 14 F O sheet mulching, 12-13 French drain, 30 organic mulch, 25 sod cutting, 11 H P soil solarization, 13 herbicides, 14 planning xeriscapes, 6 W hydroseeding, 10 base plan, 6 water audits, 24, 27 I design considerations, 7 watering icons, 2 low maintenance tips, 7 by hand, 22 inorganic mulch, 25-26 resources, 7 depth, 18 introduction, 4 what to plant first, 6 frequency, 18 invasive plants, 16, 35 planting, 15 irrigation systems, 19-24 irrigation grouping, 15,17 zones, 17 automatic timers, 24 zonal planting, 15 weeds design, 17 plants barrier, 13 lawn, 23 buying, 17 growth control, 25 micro/drip, 19 invasive, 16, 35 invasive, 16, 35 schedules, 17, 22-24 planting strategies, 15 West Bench Irrigation District, system maintenance, 24, 27 selection, xeriscape, 15–16 2, 5, 40 using rainwater runoff, 30 for West Bench, 31-35 X zones, 17 R xeriscape irrigation schedule rainwater runoff, 29, 31–32 on the West Bench, 5 for micro/drip irrigation, 20 Real Estate Foundation of BC, 40 xeriscape principles, 5 for hand or sprinkler 23 resource list, 36-37 efficient irrigation, 17 for West Bench lawns, 24 rototilling for turf removal, 14 maintenance, 27 K S mulch, 25 Kentucky Blue Grass septic drainage fields, 14 planning and design, 6 alternatives, 10 sheet mulching, 12-13 plant selection, 15 reduction, 10 sod cutters, 11 practical turf areas, 10 soil analysis and amendment, 8 Page 39
- 40. The Large Lot Xeriscape Design Project is jointly funded by the West Bench Irrigation District and the Real Estate Foundation of British Columbia, a non-profit corporation that provides funding to support sustainable real estate and land use practices for the benefit of British Columbians. Written by Toni Boot and Janelle Parchomchuk, this manual, Xeriscape Design Projects for Large Lots: Solutions to the Challenges of Landscaping on the West Bench, is the culmination of the Large Lot Xeriscape Design Project.