RHS Level 2 Certificate

Week 14- vegetative reproduction by cuttings

Christmas Prize Quiz

Test conditions 30 minutes Ho! Ho! Ho!

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.

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

Note - all suitable subjects are perennials.

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 organs (e.g. roots)

What happens when a cutting is taken?

The cutting is taken at a leaf node or across vascular bundles, 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

Physiological factors and rooting success

Juvenility – ideal cutting material is juvenile as the PGRs produced in mature tissue, particularly flower buds, inhibit rooting.

Turgidity – the cutting materials 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 powder form can assist this.

Physical factors and rooting success

Material must be healthy and true to type. Cut carefully from 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 new plant.

Remember that cuttings have polarity – it matters which way up they are planted.

Health and safety

The scalpels are very sharp. Take care when cutting.

Some people are allergic to the sap of some plants – use the latex gloves if you are or may be affected.

Do not get the rooting powder on your skin. Use the wet wipes if you do. Do not inhale the hormone rooting powder – put the lid on when not in use.

Leaf Cuttings

Plantlets form from callus that is created at the cut surfaces of leaf veins, provided these are touching the compost.

Various forms of cutting depending on species. Two used often are leaf petiole cuttings and leaf

section cuttings. Do not leave a snag on the stock plant Do not touch the cut surfaces No need for rooting powder

Leaf petiole cuttings

Remove entire leaf and petiole from parent plant

Trim petiole to 3cm and insert into compost so the leaf edge is just touching the compost

Water and keep warm and relatively humid. Suitable for Saintpaulia ionantha,

Kalanchoe blossfeldiana, Peperomia caperata

Leaf Section cuttings

For long leaves, select fully expanded healthy leaf, remove from parent plant.

Cut into sections across the leaf, making shallow chevrons that point towards the base helps show polarity.

Discard tip and very bottom section. Insert into compost by about 1/3 height of

cutting. Must be the right way up.

After care of a cutting

To grow a cutting needs the following:Moisture Warmth Light Oxygen

Control of transpiration in leafy cuttings is key to success – humidity, moisture in the growing medium, shade and air temperature.

Cuttings compost is low nutrient so once rooted the new plants need to be planted up into 9cm pots to grow on.

Other types of cutting

Semi-ripe cuttings – leafy; taken when the new growth has started to turn woody. Need less heat than softwood. Rooting powder used. 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

Soft wood or soft tip cuttings – taken from new growth in spring. Very sensitive to dehydration so need humidity control, gently bottom heat often helpful. Some but not all need rooting powder.

Plants for cutting types (1).

Softwood cuttings – Lavatera ‘Rosaea’, Fuschia sp. 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.

Plants for cutting types (2)

Root cuttings – Papaver orientalis; Phlox panniculata.

Leaf petiole – Sainpaulia ionantha; Peperomia caperata.

Leaf blade – Begonia rex (whole leaf); Streptocarpus rexii (remove central vein)

Leaf section - Begonia rex; Streptocarpus rexii ; Sanseveria trifasciata ‘Laurentii’

Learning outcomes

1.4 Describe the sowing and aftercare of a range of seed types sown outdoors (to complete from last week)

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.

Term Dates

Classes start again on the 4th January

Happy homework!

HAPPY CHRISTMAS!