You will almost certainly have to describe how to take a cutting in some detail. You will also need to know the examples given here.
Cuttings are taken of juvenile plant material, since this is young and roots more easily than adult material. You should probably also say somewhere that the plant from which the cutting is taken should be disease and pest free.
Softwood cuttings
Example: Pelargonium, Fuschia. Take the cutting between April and June, in the morning when the plant has more water in its stems. Select a healthy sideshoot, about 10 – 15 cm from the tip and cut just below a node. Ensure that the cutting does not dry out. Insert the cutting in cutting compost, removing all the leaves except for 2 or 3 at the tip. Keep warm and well watered.
Semi-ripe cutting
Example: Buddleja. Take this cutting between June and August. The cutting should be this years growth which is just beginning to turn woody. Cut 10 – 15 cm from the tip, just below a node, at the point where the stem is turning woody. This is because this is where secondary cambium is forming. Pot up the cutting in potting compost and keep watered. This does not need as much warmth as the softwood cutting. [A heel cutting is a type of semi-ripe cutting, where the cutting is taken with a bit of bark as well, so it is a diagonal cut instead of being straight across the stem. It looks a bit like a heel (if you’re imaginative) and is supposed to help with rooting. Lavender is propagated this way]
Hardwood cuttings
Example: Cornus, Chamaecyparis. These are taken in November to February when the plants are dormant. A stem of pencil thickness is taken and cut just below a bud and just above another bud. A straight cut is made at the bottom and a diagonal cut at the top, so that the orientation of the plant is remembered. Pot up this section of stem (which is just like a twig) in potting compost and firm in. You can provide bottom heat if available, but it should root without it. Keep watered
Division
Example: Alchemilla mollis, Rhus typhina, Hosta. These clumping hardy perennials are dug up in late autumn or early spring. The roots are divided by prising apart with two gardening forks or just by hand. The separated roots and plants can be re-planted.
Layering
Example: Cotinus coggygria, Cornus alba. This is carried out in the spring using growth that is soft enough to bend down to the ground about 30cm from the parent plant. The branch is wounded at the point where it touches the ground, pegged down and buried 7 to 10 cm deep in the soil. The rest of the stem which has been layered should be supported vertically until the autumn, when roots should have formed and the new plant can be separated from the parent.
Air layering
Example: Ficus elastica. This is a method used for plants which don’t have bendy stems. In the spring, wound a stem of pencil thickness, removing a bit of bark about 15 cm long. Wrap this wounded section with moist vermiculite and polythene. The roots should develop along this wounded section in about a year.
Serpentine layering
Example: Clematis. This is a variation of simple layering to produce more than one new plant. The bendy stem is pegged down to the ground at several points along its stem, at different nodes, each of which can root to produce a new plant.
Leaf petiole cuttings
Example: Saintpaulia ionanthes, Peperomia caperata. Select leaves from the second row of the plant (ie: not the very centre of the rosettes but not the outside layer either). Remove a leaf with the petiole attached and cut the end of the petiole so that it is about 2cm in length. Dip the cutting in rooting hormone and pot it up into a well-draining potting compost. The medium should be 2:1 perlite to potting compost. The blade of the leaf should be resting on the surface of the compost, with the petiole buried. The cutting should be placed in a propagator and kept warm and humid with good light. Overhead watering may be detrimental to these cuttings. Rosettes of leaves should form in 8 weeks.
Leaf lamina cuttings
Example: Streptocarpus. Choose a fully-grown leaf and cut it in half along the main rib. Discard the mid-rib itself and insert the cut edge of the leaf in a 1:1 mix of perlite and potting compost. Firm in and water, placing the cutting in a propagator but not in direct sun. The cover of the propagator should be removed when the plantlets form. The cutting can be potted on when several leaves have formed.
Example: Begonia rex. Taking a mature leaf, score across the main veins on the underside of the leaf. The leaf is then pinned or weighted down with the cuts touching the compost. The cutting should be kept warm at 20 Celsius and moist until the plantlets form.
Leaf bud cuttings
Example: Camellia, Clematis. In spring, a healthy, juvenile stem is cut into sections comprising a leaf, petiole and a short section of stem with a bud. If there are two leaves opposite each other on the section of stem cutting, the stem is cut in half vertically so that only one leaf is attached to the cutting. Dip the bottom of the cutting in rooting hormone and pot up with the bud just above the surface of the soil. Place this cutting in indirect sun with some bottom heat.
Root cuttings
Vertical root cuttings example: Acanthus mollis, Rhus typhina. Horizontal root cuttings example: Primula denticulate. The cuttings are taken between September and November from a mature, healthy and disease-free parent plant. The parent plant is dug up and the roots washed. Select unblemished roots of about pencil thickness and remove the side shoots. Cut lengths of root of about 5 cm long. Make sure that orientation cuttings are made, with a straight cut at the top and a diagonal at the bottom for the vertical cuttings. Place the cutting in compost, either vertically with the top of the root cutting level with the top of the compost, or horizontally. Cover with 0.5 cm of compost or the same depth of grit and keep moist in a cold frame. Water only a little as root cuttings rot easily.
After care
After the plants have been propagated, any diseased leaves should be removed and destroyed. Any plant wounds are more susceptible to grey mould, so monitor the plants for disease. But if it all goes well, the plants may be potted on, fed and hardened off.
Yay! That’s the end of R2104, and the end of the modules for the first certificate! Please remember to like this post if it has been helpful to you, and follow for more. If you’ve got any questions about the exams etc, just leave me a comment and I’ll try to help.
Gardening studies 