Layering – simple shrub propagation

This is possibly the simplest method of propagating shrubs.
Deciduous species are best layered in autumn or winter; evergreens in autumn or spring.
Select a non-flowering branch from the current season’s growth which is flexible enough to touch the ground when bent.
Where the underside touches the soil, make a cut halfway through to form a tongue.
Bury this section 2-3in in the soil, peg down firmly with a U-shaped pin, and cover the split section with compost.
Leave the growing tip exposed and, if possible, stake it upright.
A flat stone placed over the buried section will help to hold it in position, keep it cool and preserve moisture.
In about a year’s time, the wounded section should have taken root, and it can then be severed from the parent plant and replanted.

Dividing roots and rhizomes

Most herbaceous perennial plants, such as lupins, delphiniums or rudbeckias, can be propagated by division, either in spring or late autumn.
Lift clumps and divide into sections.
If the root clump is large and overgrown, divide it after lifting by thrusting two digging forks back to back into the centre and levering them apart.
Plants with tough woody crowns may have to be split with a sharp, strong-bladed knife.
Dust the cut surfaces with sulphur to prevent fungal growth.
Select pieces with healthy roots and strong growth buds.
Replant immediately in well-prepared ground.
Some plants, such as irises, produce swollen, horizontal stems called rhizomes.
Lift clumps when they become overcrowded, and use a sharp knife to cut them apart.
Select young, healthy rhizomes with a fan of leaves attached. Plant them with the rhizomes facing south – they thrive in sun – and just visible on the surface of the soil.

Water lilies have thick rhizomes; in spring, lift overcrowded clumps out of the water, clean, and divide with a sharp knife, selecting the younger growths for replanting.
Each one must have several strong buds and roots.

Increasing bulbous plants
Both bulbs and corms reproduce by means of small offsets – known as bulbils and cormlets – which form around the sides of the parent bulb or corm during the growing season.
Propagate bulbs before they become overcrowded and flower poorly.
Lift the bulbs after their leaves have died back and they are dormant.
Remove the bulbils and grow them for 2-3 years in a nursery bed until they reach flowering size.
Then plant them in their permanent position.
Snowdrops are lifted and divided immediately after flowering, when the foliage is still green.

Lilies produce bulbils, but can also be propagated by using the fleshy scales of the bulb.
When the bulbs are dormant, pull off a few outer scales and place them in a moist, peat-based compost in a polythene bag.
Shake the bag to ensure the scales are fully covered, secure it, and place it in an airing cupboard or a propagator.
When tiny bulbils have formed, plant in pots or trays for planting out in 1-3 years.
Some lilies form bulbils in the axils of the leaves.
Collect these in late summer and sow immediately, in pots or boxes in a cold frame or in nursery rows outside.
Plant out in their final positions in 3-4 years.

CORMS AND CORMLETS. Gladioli and crocuses develop new corms at the bottom of the flowering stems.
These are retained and the old ones discarded when the corms are lifted after flowering.
The old corms also develop cormlets which can be stored in a cool, dry place until spring (gladioli) or autumn (crocuses) and then planted in potting compost.
Grow on the cormlets until autumn (or late spring for crocuses), then lift and store them for planting the following spring (or autumn for crocuses).
They reach flowering size in 1-3 years.