By Deryn Thorpe
Growing plants from cuttings is an inexpensive and rewarding way to increase your stocks of plants.
You can use cuttings to produce enough plants for a hedge, create plants for yourself or to give away to friends and clone a plant that has a special memory before you leave your garden.
If you have not done it before start off with plants that grow readily from cuttings like pelargoniums (geraniums), wormwood and lavender. These are very easy to strike (this term means getting the cutting to grow roots). Just cut off a piece and just push it into the soil. If you give them a little water and shade most will take root. Other plants are slightly harder to get going and you need to know what time of the year to take cuttings and what part of the plant to use for the propagating material. Growing from cuttings is very rewarding and inexpensive as you need nothing more than a pair of secateurs, some old pots (well cleaned) and a planting medium. Professional nurseries also use hormone gel which is dabbed onto the end of the cutting to stimulate root growth but this is an optional extra and can be replaced by untreated honey.
The best planting medium for cuttings is one part river sand to one part coir peat (coco peat) but many cuttings will strike well in potting mix.
Put the cuttings into the soil mixture and firm them down with your fingers.
Nurseries keep the plants moist in glasshouses with misting devices. A home alternative is to provide cuttings with their own mini glasshouse. Invert a glass jar or a plastic drink bottle with the neck cut off over the cuttings or use a clear plastic bag supported by stakes or a wire coat hanger.
Provide shade from direct sunlight. Most cuttings strike best at a temperature between 20-25 degrees Celsius.
Do not remove the cuttings from the pot until the roots are well grown.
In late autumn and winter take hardwood cuttings - which is usually the previous year’s growth that has hardened in autumn or more usually in winter. This wood snaps when you bend it. These cuttings (roses are an example) will take many months to strike.
Semi ripe cuttings
Semi ripe cuttings are made from broad leafed evergreen trees and shrubs using the wood that has changed colour from green to brown, are taken from evergreens in February and March. Cut the piece of branch between 10cm and 15cm long.
Plants from narrow leafed plants (like conifers) are usually taken as ‘heeled cuttings’. Take a shoot that comes of a branch and pull off a piece of the branch as well so it has a heel. You don’t remove the tip of these cuttings as it has hormones that help rooting. Expect roots to grow in one to two months.
Tip cuttings are taken in spring and early summer. With these cuttings, which can be up to 10cm long, leave a few leaves on the top and strip the others away to help conserve moisture.
Take the cutting just below a node (the notch where the leaf will come out) as this is where the roots will appear.
Some plants need ‘bottom heat; to strike, you can buy these from mail order nurseries like Diggers Plants.
Some plants like African violets, begonias and succulents grow easily from a leaf. While some of the rosette-style succulents grow from offshoots many reproduce from leaves. The ones most likely to do so have leaves that easily fall from the plant such as Echeveria, Gasteria, Graptopetalum, Kalanchoe, Sansevieria and Sedum. Most varieties will root well if you leave the succulent leaves sitting on the top of the potting mix (a specialised cactus and succulent one is recommended) and new roots will form. This can be done at any time of the year. Some varieties like to have the leaf base tucked into the mix.
As African violets and begonias are indoor plants leaf cuttings can be taken year round. The actual leaf does not grow into a plant but new roots form and the plant grows around it.