Your guide to propagating plants with layering

One of the most fascinating — and easy — ways to propagate plants is by layering. Layering involves burying a stem in soil to induce it to root while it's still attached to the parent plant.

Layering is usually slower than rooting stem cuttings, but it's much more dependable.

The three ways to layer — simple layering, mound layering and air layering — have in common one crucial step.

• To get a stem to develop roots where you want them, you must distress it, which activates the plant's survival instincts.
• It's a good idea to dust a little rooting powder on the wounded section of the stem before covering it up.

All you have to do is bend down a long stem so that a section can be buried five centimetres below the ground.

1. Pinch off leaves in the buried section of stem and distress it near a node.
2. Hold the buried section of stem in place with a stone or wire pin.
3. Stems set to layer in spring are usually ready to dig and move by late summer, or you can wait until the following spring.

It works especially well with vines; raspberries; forsythias; climbing or rambling roses; and herbs, including rosemary, tarragon and thyme.

This method is particularly effective with ground covers, shrubs and scented geraniums.

1. Before growth begins in spring, cut down all stems to a few centimetres above the ground to force out new basal shoots.
2. When the shoots reach 15 centimetres tall, cover them eight centimetres deep with a mound of damp compost or peat moss so the base of the plant senses that it is underground.
3. After six weeks or so, remove the mound and clip off the stems you want to root near the soil line. Then handle them like rooted cuttings, because they will have root buds.

If you can't bring the stem to the soil, bring soil to the stem with air layering. This method is often used to propagate sheffleras, philodendrons and other upright houseplants, but you also can use it with outdoor plants.

1. Make a slit on a branch between 15 and 45 centimetres from the tip and insert a matchstick to hold it open.
2. Wrap a wad of moist sphagnum moss around the wound and cover with aluminum foil. Cover that with a plastic sleeve and tie the ends tightly.
3. Check occasionally to see if the moss is still moist and whether roots have formed, which can take several months.
4. Once roots are visible, cut the stem and treat it like a halfway-rooted cutting.