Layering is an early method of propagating plants by encouraging sections or tips of stems to root while attached to the parent plant. In the wild, plants with long, pliable stems, ‘such as shrubby dog roses and brambles, make new plants by ‘rooting’ whenever suitable sections stay in contact with the ground. We can encourage the same process to make new plants for the home.
On the whole, the plants suitable for layering are plants for porches and patios, such as Honeysuckle and Jasmine. Some plants grown by this method can be brought inside for a temporary display, and many make good plants for window-boxes or small tubs.
In a garden, plants are layered by bringing the stems into contact with the soil. On the patio, large pots filled with compost can be used instead. Rooting can occur in five to six weeks or, with woodier plants, it may take two to three years.
Layering woody-stemmed shrubs September, October and November are the best months to attempt this kind of layering, but it can be done at any time of the year. Stems should be one or two years old, pliable and long enough to be bent down without snapping.
First test the feasibility. Bend the stem down to pot height and make sure that a sufficiently long section of the growing end is left, so that it can be fastened to a cane pushed into the compost at an upright angle.
Many plants have to be ‘wounded’ to make roots more readily. Do this at the point where the stem will be in contact with the compost, either by taking off some of the bark on the stem or by making a slanting cut about 2.5-5cm (1-2in), about one third of the way through the stem. Hormone powder dusted onto the wound hastens rooting.
Next, peg down the wounded section so that it is in close contact with the compost. Use a bent piece of wire for the peg or weigh down the stem with a small heap of stones and then cover the section with gritty compost. Fasten the shoot to a cane for support.
After about a year the stem should be severed (usually sharp secateurs are needed), and a few weeks after that the new plant can be transplanted.
Layering softer-stemmed plants
Many of the perennial plants used in window-boxes and tubs begin to look straggly after a year or so, and can be renewed by layering. This is a good way of growing new carnations, pinks, and other low-growing plants with prominent nodes on the stems and semi-woody growth. These usually root quickly, and layering can be done in the container in. which the parent plant is growing.
In July and August, bend a strong, healthy shoot down into a depression made in the compost next to the plant. Strip off the lower leaves that would otherwise be buried in the soil and make a cut in the shoot, just below the remaining tuft of leaves. Apply hormone rooting powder and peg down. Surround the section to be layered with a compost made up of equal parts peat and sharp sand or grit and keep just moist.
After six weeks the shoot can normally be severed from the parent and transplanted four weeks later.
Plantlets on runners
Plants that make plantlets at the ends of runners, singly or in clusters, root freely when they come into contact with a suitable rooting medium, and this can also be called layering.
This is an easy way of producing new Strawberry plants and house plants such as Mother of Thousands and Spider Plant.
Strawberry plantlets are pegged with wire, either into the compost in the same pot as the parent plant, or into smaller pots filled with an open rooting mixture (equal parts peat and coarse sand or grit). These are plunged up to their rims in the larger pot.
The house plants mentioned are induced to make roots of their own by pegging the plandets down into contact with a similar rooting mixture in pots placed adjacent to the parent plant. When new growth appears, the runners can then be cut through.
How to layer plants
- Fill a small pot with peat-based compost. Choose a branch or stem of soft or semi-ripe growth. Check that it is long enough to reach the pottint; mixture.
- Pinch out or cut off any leaves that L cook! Be buried in the potting mixture. Make a cut in the shoot just below the remaining tuft of leaves.
- Use a hairpin, v-shaped wire or paper-11..) clip to carefully hold the prepared stem firmly in contact with the potting mixture. Surround it with the rooting mixture.
- After approximately 6 weeks the shoot ..”’ can be severed from the parent. The tip of the stein should be tied to a thin cane to encourage roots to form.
Plants suitable for layering
- Clematis (Clematis species)
- Jasmine (Jasminium nudiflorum)
- Honeysuckle (Lonicera species)
- Trumpet Vine (Campsis species)
- Cotoneaster (Cotoneaster species)
- Blackberry (Rubus fructicosus) (particularly tip layering)
- Loganberry (Rubus loganobaccus) (particularly tip layering)
- Rhododendron (Rhododendron species)
- Grape Vines (Vitis species)
- Magnolia can be propagated by layering. It flowers in spring.
- Border carnations and Pinks (Dianthus species)
- Strawberry (Fragaria)
- Hoya (Hoya carnosa)
- Ivies (Hedera species)
- Heather (Erica species)
Houseplants that make runners
- Mother of Thousands (Saxifraga stolonifera)
- Spider Plant (Chlorophytum comosum)
- Wild Violet (Viola odorata)
Tip layering
Tip layering is a useful technique for raspberries and blackberries, which can be grown in large tubs. Bend a soft growing tip into a pot of compost, peg it down and shallowly cover it with gritty compost. By early autumn the young tip will have grown up through the covering and sent down roots and by early spring it can be cut from the parent.