4.Understand Methods of Vegetative Propagation

Question 1

Ideal characteristics of parent plant

Answer 1

• Free from pest and disease
• Juvenile growth (usually semi-ripe)
• Parent plant capable of producing sufficient propagating material
• No obvious nutrient deficiency - sturdy, good green colour

Question 2

Describe division

Answer 2

• Most easily done on clump forming plants
• Plants can be dug up and separated - sometimes by hand
• Young shoots with own roots can be separated
• Woody roots may be tangled and must be handles with care
• Flowering plants - separate when dormant
• Grasses - best divided during active growth
• Often planted straight out but vulnerable roots may need container first
• E.g Hosta species

Question 3

Describe Layering

Answer 3

• Encouraging shoots to form roots while still attached to parent plant
• Mid-step between division and cutting
• Must be young, vigorous and able to bend to ground level without damage
• Wounding to cambium layer can encourage root formation
• Branch is embedded into ground until roots form
• E.g Acer

Question 4

Describe Air layering

Answer 4

• Active growing branch is wounded above ground level
• Vermiculite and black plastic wrapped around and held in place until roots form
• Only suitable for plants which root above ground
• E.g Rubber plant

Question 5

Describe Cutting

Answer 5

• Most widely used method
• Removing shoots encouraging root formation
• Create a fully independent plant
• Cutting taken in summer - maturing but still active growth
• Sample is cut below a node as roots are most likely to form here
• Planted directly into growing medium
• Plant can be potted in sterile compost - aeration needed/ perlite/grit
• Must be kept warm and avoid dehydration
• E.g Dahlia

Question 6

Key considerations when propagating from Cutting

Answer 6

• Hygiene is important, use clean equip - exposed areas are vulnerable
• Cambium needed - the more cambium the easier roots will form as here contains the most amount of root forming tissue
• Rooting powder/gel can be used to stimulate growth
• Buds/flowers removed to prevent decay
• Avoid excessive heat and over crowding
• Remove dead leaves to deter fungal growth
• Take more cuttings than plants wanted as success will vary

Question 7

Describe Hardwood cutting

Answer 7

• Mature material or dormant buds are used rather than young growth
• Usually done in autumn/winter
• Slow growth
• Often done in a nursery bed
• Dutch roll can be used - Black plastic wraps cuttings and soil
• E.g Willow

Question 8

Describe Heel cutting

Answer 8

• Young growth pulled away from crown/heel of plant (where active cambium is)
• Used for herbaceous diocots
• E.g Aster/Ilex

Question 9

Describe Leaf cutting

Answer 9

• Mostly used for tropical plants
• Leaves can be planted direct into sterile compost or kept on moist tissue until roots form
• E.g Peperomia spp