layering and division

1. RHS Level 2 Certificate
Week 15- vegetative
reproduction by stem
cuttings, layering and
division.

2. Learning objectives
 Review of stem cuttings.
 1.1 State the physiological factors to be fulfilled for successful
propagation by layering.
 1.2 Describe how to propagate ONE NAMED plant for EACH of
the following types of layering: air; simple; and serpentine
 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 how to propagate by division ONE NAMED plant
of EACH of the following types: a suckering shrub; a fibrous-
rooted perennial; a perennial with distinct buds (eyes).
 1.6 Describe the aftercare of plants propagated by division.
 1.7 Describe propagation facilities for each form of vegetative
propagation - heated propagator, mist bench, cold frame, open
ground

3. Stem cuttings
 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, gentle bottom heat often
helpful. Some but not all need rooting powder.

4. Characteristics of plant material for
propagation
 True to type – must show the characteristics
you want.
 Healthy – no signs of virus, no obvious or
severe infestation or infection.
 Turgid – must be well watered and protected
from dehydration after removal from parent.
 Juvenile – the more juvenile the material the
better it is likely to root.

5. 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 x rubrum
 Aftercare – weed to reduce competition, do not allow
soil to dry out.

6. Plants that can be divided
 Iris ensata (or any rhizomatous iris)
 Epimedium x rubrum
 Bergenia purpurescens
 Hosta sieboldiana
 Phyllostachys nigra
 Sarcoccoa hookeriana

7. 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.

8. 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

9. 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.

10. Propagation Environments – mist
bench
 Combines heating
with mist irrigation in
a protected
environment.
 Misting provides
irrigation and controls
transpiration.
 Two forms of
electronic control for
misting – electronic
leaf or timer.

11. Propagator – heated or unheated?
 A tray and cover which provides protection
and higher relative humidity and temperature
than the base environment.
 Vents allow renewal of air within and
humidity control
 Heat element controlled by a thermostat
allows precise control of growing media
temperature.
 May be more convenient to combine a heat
pad with an unheated propagator unit.

12. Cold frame
 Low lidded structure made of wood or metal
and glass or polycarbonate. Lid can be
raised or lowered.
 Provides protection from wind and weather
and some frost protection for hardy plants.
Used for cuttings where soil temperature
need not be greater than the ambient.

13. Which environment for which?
 Soft wood cuttings of Fuchsia?
 Hard wood cuttings of Ribes nigrum?
 Semi ripe cuttings of Artemisia ‘Powis Castle’
(NB: grey hairy lobed leaves)
 Newly sown seeds
 Pricked out seedlings

14. Learning outcomes
 Review of stem cuttings.
 1.1 State the physiological factors to be fulfilled for successful
propagation by layering.
 1.2 Describe how to propagate ONE NAMED plant for EACH of
the following types of layering: air; simple; and serpentine
 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 how to propagate by division ONE NAMED plant
of EACH of the following types: a suckering shrub; a fibrous-
rooted perennial; a perennial with distinct buds (eyes).
 1.6 Describe the aftercare of plants propagated by division.
 1.7 Describe propagation facilities for each form of vegetative
propagation - heated propagator, mist bench, cold frame, open
ground