Favourite shrubs, trees and plants that have given years of pleasure can be easily reproduced at home in the garden. Whether you want to have a new plant that's slow to grow from seed, reproduce a hybrid that won't come true from seed, fill a large empty, space economically with several new plant, or give a plant no longer commercially available to a friend, propagating plants by using softwood cuttings quickly produces clones identical to the parent.
June or July is the best time to propagate many kinds of plant, although late spring and summer work, too. Softwood cuttings, or slips, root readily in midsummer. Take slips from actively growing side shoots—the soft, flexible new growth.
Select healthy, straight side stems and cut them at the base, flush with the central cane or stalk. Trim them to six to eight inches (15 to 20 centimetres) with a clean, sharp knife or razor blade. (Avoid using pruners; they crush plant tissues and invite fungus infection.) Make sure each cutting has at least three leaf nodes, which is where a leaf or pair of leaves meet the stem; roots develop from these sites. You can also take slips from central-growing branches; cut the stem one-half inch (one centimetre) below a node. The exceptions are boxwood, cotoneaster and pyracantha—they root better when the cut is made directly under the node.
Step 1. It's important to maintain moisture and air circulation around the cuttings immediately after they're taken. They shouldn't be allowed to dry out, but putting them in a jar of water deprives them of oxygen and encourages the cut tissues to rot. Instead, enclose a wet cloth in a plastic bag and insert the cuttings into the folds of the cloth as you move along in the garden, taking your cuttings. For best rooting results, insert cuttings into pots with rooting medium within 30 minutes. Recut the ends on a long slant so more tissue is exposed to absorb water.
Step 2. Next, trim the leaves from the bottom half of the stem. Don't pull them off; this produces small tears in the stem that can become infected and kill the cutting.
Use soilless mix or equal parts coarse sand and peat moss to fill clean pots that have drainage holes. Water lightly with warm tap water but don't saturate the mixture'this drives out oxygen and invites fungus infections. Stick the stems firmly into the mix with no more than half of their length below the growing medium. Several cuttings can be set into one pot. Make sure each stands upright and leaves aren't touching.
Step 3. You can use powdered rooting hormone labelled No. 2 to speed up the rooting. The powder contains indolebutyric acid, a natural plant hormone that stimulates growth. Moisten cut end in water, shake off the excess and dip in the powder. Use a pencil to make a hole in the medium. If you stick the cutting in the soil without first making a hole, you'll rub off the powder when you insert the cutting. Carefully lower the powdered end of the cutting into the hole and firm the growing medium around the stem.
Step 4. Set the pot filled with cuttings in a plastic bag to help maintain consistent humidity, but don't seal the bag. Allow the top to remain open for air circulation. Check every other day to be sure the growing medium is moist.
Place the pot in a shady spot for 10 days, then gradually move it into brighter light that includes some direct sun. Exceptions are broad-leaf evergreens such as euonymus and boxwood, which prefer to remain in light shade. If you're rooting cuttings indoors, set them nine inches (23 centimetres) below cool white fluorescent bulbs at this stage.