RHS Level 2 Certificate

Week 15- vegetative reproduction by layering, division, budding and grafting

Learning outcomes

1.1 State the physiological factors to be fulfilled for successful propagation by layering.

1.2 Describe a range of different types of layering.1.3 Describe the aftercare required for plants raised by layering.1.4 State the conditions which have to be met to ensure

successful propagation by division.1.5 Describe the propagation of plants by division.1.6 Describe the aftercare of plants propagated by division.1.7 Define the terms: ‘budding’ and ‘grafting’.1.8 State the reasons for use of budding and grafting for the

production of particular plants. Define ‘Compatibility’ in this context.

Propagation by division

Used for perennials – clump forming, suckering and rhizomes.

Use more juvenile offsets from the edge of the clump or plant.

Divide summer flowering plants in the spring or autumn e.g, Iris ensata

Divide spring flowering plants in the summer after flowering e.g. Epimedium rubrum

Aftercare – weed to reduce competition, do not allow soil to dry out.

Plants that can be divided

Iris ensata (or any rhizomatous iris) Epimedium rubrum Bergenia purpurescens Hosta sieboldiana Phyllostachys nigra

Propagation by layering

Simple layering – advantages: can be used to propagate hard to root plants; needs little equipment; no hardening off

Disadvantages – produces relatively few plants and is slow.

Propagation by layering

Serpentine layering -Used for woody climbers e.g, Lonicera. Produces several plants per stem however it needs quite a lot of space.

Air Layering – used for plants with rigid stems e.g. Magnolia grandiflora

Aftercare for layered plants

Keep soil moist (sphagnum moss in air layering) until rooting occurs.

Once rooted (and shoots are produced in serpentine layering) detach from the parent plant and move to final position or into a pot to grow on. Remove any residual stem from the parent plant without leaving a snag.

Propagation by grafting and budding

The joining of separate plant parts together, such that they form a union and grow   as one plant.  Most apple, pear and stone fruit trees are propagated in this way.

Scion – the wood from the desired variety from which the graft or bud is taken

Rootstock – the rooted plant of the same species (occasionally same genera) onto which the scion is attached.

Reasons for grafting or budding

Plants that cannot be produced by other means To obtain earlier cropping To obtain desirable characteristics of the rootstock

e.g. dwarfing To change the variety of an established tree

(topworking) To repair damage (bridge grafting) To create particular ornamental or useful forms (e.g.

standard roses or family apple trees)

Stages of graft union formation

It is essential that the cambium on the scion and stock is matched up

1) Callus formation by both stock and scion 

2) Intermingling of callus from stock and scion 

3) New cambium forms in callus between stock and scion 

4) New secondary xylem and phloem from new cambium to connect stock and scion 

FACTORS AFFECTING SUCCESS OF GRAFTING AND BUDDING

Plant type – scion and stock from same species (intra-generic grafts may be feasible – e.g. Pyrus communis scion onto Cydonia oblonga rootstock). Only dicots and gymnosperms can be grafted.

Incompatibility – due to physiological factors; virus infection; physical abnormality of the vascular tissues in the graft union.

Season and growth state Environment – temperature, humidity.

Types of graft and budding

Whip and tongue graft Apical wedge graft T-budding Chip budding

Learning outcomes

1.1 State the physiological factors to be fulfilled for successful propagation by layering.

1.2 Describe a range of different types of layering.1.3 Describe the aftercare required for plants raised by layering.1.4 State the conditions which have to be met to ensure

successful propagation by division.1.5 Describe the propagation of plants by division.1.6 Describe the aftercare of plants propagated by division.1.7 Define the terms: ‘budding’ and ‘grafting’.1.8 State the reasons for use of budding and grafting for the

production of particular plants. Define ‘Compatibility’ in this context.