Rhs level 2 certificate year 1 session 14 overview 2013
- 1. RHS Level 2 Certificate Week 14- vegetative reproduction by cuttings
- 2. Learning outcomes 1.4 1.1 State the role of physiological factors upon the speed and success of rooting of cuttings. 1.2 Name the types of stem cuttings. 1.3 Describe the propagation of plants using a range of stem cuttings. 1.4 Describe the propagation of plants using a range of leaf cuttings. 1.5 Describe the propagation of one plant using root cuttings. 1.6 State the environmental requirements for successful rooting of each of the types of cutting in 1.2, 1.3, 1.4 and 1.5. 1.7 Describe the equipment required to propagate plants by cuttings. 1.8 Describe the aftercare required for plants raised by cuttings.
- 3. Quiz - answers 1. 2. 3. 4. The production of new plants by human intervention. Vegetative – ‘will not come true from seed’, ‘are variegated’, ’have a very long juvenile period’. Seed – ‘produce a lot of seed’, ’germinate easily’, ‘are relatively short lived’ Seed – Impatiens walleriana, Liatris spicata Vegetative- Ananas comosus, Malus domestica Scarification – chipping or abrading the seed coat to allow water in.
- 4. Quiz - answers 5. 6. 7. 8. 9. 10. Stratification – exposing the sown seed to low or high temperatures for a know period of time to break dormancy. Requires cool, dry storage. Mix the seed with fine, dry silver sand (1 part seed to 2 parts sand). Mix, use a fold of paper or a cupped hand to scatter the seed/sand mix over a prepared tray. It reduces competition from weeds By the leaves (ideally the seed leaves) never the stem or roots. Good hygiene – clean trays, sterile compost, tap water. Do not sow too thickly. Control watering and humidity.
- 5. What is vegetative reproduction? growing a new plant from some part of an existing plant e.g. strawberry a plant that is produced in this way is genetically identical to the original plant – it is a clone
- 6. How does it work? Newly produced plant cells contain all the genetic information needed to make a new individual (totipotent cells) New plant cells are made by plant meristems They divide and under the influence of plant growth regulators become part of plant tissues (e.g. roots)
- 7. What happens when a cutting is taken? The cutting is taken at a leaf node, there is a large area of meristem. The cells divide quickly and form callus These callus cells differentiate under the influence of auxin and cytokinin and become root cells
- 8. Physiological factors and rooting success Juvenility – ideal cutting material is juvenile Turgidity – the cutting material’s cells must be full of water. Plant Growth Regulators – Auxin and cytokinin act together at the base of the cutting to produce roots. Using artificial auxin in power form can assist this.
- 9. Physical factors and rooting success Material must be healthy and true to type. Cut carefully from the stock plant to avoid damage to the stock plant – no snags. Secateurs are fine here. Use a sharp cutting knife or scalpel to prepare the cutting – to avoid crushing the xylem and phloem in the cutting stem which will form the basis of the vascular system of the roots of the new plant. Cuttings have polarity – it matters which way up they are planted. Obvious with leafy cuttings but not so for hardwood or root cuttings.
- 10. Health and safety Take care when cutting. Some people are allergic to the sap of some plants – use gloves if you are or may be affected. Do not get the rooting powder on your skin. Use wet wipes if you do. Do not inhale the rooting powder – put the lid on when not in use.
- 11. To take a softwood cutting (1) Chose a side shoot from the ‘mother’ plant and cut it with the secateurs just above a leaf node about 10cm from the tip Then cut the stem of the cutting with the scalpel on the tile just below a leaf node about 6-8cm from the tip Remove the lower leaves with the scalpel so that the cutting has a length of bare stem and 2-3 sets of leaves at most Dip the base in rooting powder if required– carefully and tap off any excess. Too much auxin prevents rooting.
- 12. To take a softwood cutting (2) Make a hole in the compost with a dibber or pencil. Insert the cutting into the hole up to just below the bottom set of leaves. Firm the compost round the cutting with your fingertips gently Label Place in a closed propagator at the required temperature. Bottom heat assists rooting
- 13. After care of a cutting To grow a cutting needs the following: Moisture Warmth Light Oxygen Nutrients Control of transpiration in leafy cuttings is key to success – humidity, moisture in the growing medium, shade and air temperature.
- 14. Other types of cutting Semi-ripe cuttings – leafy; taken when the new growth has started to turn woody. Need less heat than softwood. Shrubs. Hardwood cuttings – taken whilst stock plant is dormant. Rooted outdoors or in cold frame. Plant the right way up! Trees Root cuttings – taken when stock plant is dormant. Plant the right way up! Herbaceous perennials Leaf cuttings – leaf section; leaf blade (lamina); leaf petiole. House plants.
- 15. Plants for cutting types (1). Softwood cuttings – Lavatera ‘Rosaea’, Fuschia spp. Many deciduous trees, shrubs and herbaceous plants will root by this method. Semi-ripe cuttings- Weigela florida; Ligustrum ovalifolium; Lavendula angustifolia ‘Hidcote’ Hardwood cuttings – Salix magnifica; Populus nigra; Forsythia x intermedia.
- 16. Plants for cutting types (2) Root cuttings – Papaver orientalis; Phlox panniculata. Leaf petiole – Sainpaulia ionantha; Peperomia caperata. Leaf lamina – Begonia rex (whole leaf) Midrib - Streptocarpus rexii (remove central vein) Leaf section - Begonia rex (squares); Streptocarpus rexii ; Sanseveria trifasciata ‘Laurentii’ (chevrons)
- 17. Pests and diseases Sap suckers – aphid, whitefly, mealy bug etc Slugs – hard wood cuttings at risk if in a coldframe. Fungal diseases – powdery mildew, downy mildew. Viral diseases – various.
- 18. Learning outcomes 1.1 State the role of physiological factors upon the speed and success of rooting of cuttings. 1.2 Name the types of stem cuttings. 1.3 Describe the propagation of plants using a range of stem cuttings. 1.4 Describe the propagation of plants using a range of leaf cuttings. 1.5 Describe the propagation of one plant using root cuttings. 1.6 State the environmental requirements for successful rooting of each of the types of cutting in 1.2, 1.3, 1.4 and 1.5. 1.7 Describe the equipment required to propagate plants by cuttings. 1.8 Describe the aftercare required for plants raised by cuttings.