I am an inveterate cutting-taker. I don’t mean that I go around other people’s gardens pinching off - and pinching - suitable material to use for cuttings; certainly not. But I do take lots of cuttings from my own garden, and the gardens of generous friends, to grow on and give to friends or to donate to charitable events. There is nothing more satisfying than being able to share some of your best-loved specimens with others, and taking cuttings is one of the easiest ways of doing this.
A word of warning – make sure that the plants you are taking cuttings from are not governed by Plant Breeders Rights (PBR). This means that the breeder of the particular plant has a form of intellectual property rights over it, preventing anyone from benefiting from propagating it, selling it, and so on, without the breeder’s authority.
If you do take cuttings, don’t expect all of them to ‘take’, namely, to produce new roots and shoots. Some will inevitably die before they have a chance to live, as it were, so don’t be disappointed if you do lose a good number. As a general rule of thumb, I always take twice the number of cuttings as the number of plants I would like to end up with - I usually end up with a better success rate than that, but I like to be on the safe side.
There are a number of types of cuttings: softwood, basal, semi-ripe, hardwood and root. They are taken at different times of the year
In spring you can take softwood cuttings from shrubs. Material is taken from the soft and flexible young shoot tips, which root readily at this time of year. The best time of day to do this is in the morning when the plant is turgid, or full of water. Before you start taking cuttings, make sure you have a clean, sharp knife and have ready some clean, 9 cm pots filled with compost. The number of pots depends on how many cuttings you wish to take: you can fit four or five in a pot. Select a non-flowering shoot and cut it just above where the leaves join the stem - the node. You need a shoot about 10cm long. Pop the shoots into a plastic bag until you are ready to prepare them for planting: this will prevent them from wilting. When you are ready to plant them, take them out of the plastic bag and, with a sharp knife, cut the bottom of the shoot off to just below a node. Carefully remove the lower leaves and pinch out the top of the shoot.
It’s at this point when you can dip the shoot into a hormone rooting gel, liquid or powder which contains plant hormones and usually a fungicide which, respectively, causes stem cells to grow and develop, and reduces the chance of fungal infection. (I say arguably, because I didn’t seem to have any better results when I used a rooting gel than when I didn’t - have a go yourself and see what happens.)
Then make a hole in the pot of compost near to the edge - you can use a dibber, but I use a pencil which seems to do just as good a job – pop the cutting in so that the first set of leaves is above the surface of the compost and push the compost back around the cutting. Water the pot from above so that the compost settles around the cutting.
If you have a heated propagator this is ideal, but I pop each pot into a large plastic freezer bag and use the thin paper-coated wire tie to loosely pull the opening together at the top. I don’t tie it tightly, but leave a small gap so that a certain amount of air can still circulate. The whole thing then goes on the window sill, and because the pot is inside the bag, you don’t need to worry about standing the pot on a saucer. Don’t put the pot in direct sunlight, though, as this will scorch the leaves. Open up the bag periodically to aid ventilation and remove any dead or decaying material as you see it. Keep the compost moist. The cuttings should develop roots in about ten weeks and, once they are well rooted you can pot them on into their own individual pots. As long as you can do this by mid-summer they will develop enough roots to carry them through the winter, otherwise leave them and pot them up next spring.
If you want to take cuttings from tender or borderline tender perennials, such as Penstemon and Verbena rigida follow the same procedure for taking softwood cuttings, but make sure you keep them undercover in a light, frost-free environment at all stages, until next year when they can be planted out in the garden when there is no danger of frost.
A similar method to taking soft wood cuttings is used to take cuttings from some perennials. The only difference is that the cuttings are taken from the base of the plant where the young shoots start to grow in spring: these are called basal cuttings. Take the shoots from as close to the base as possible and then treat them just as you would soft wood cuttings.
Late summer into autumn is the time to take semi-ripe cuttings. These are cuttings from the current season’s growth where the base of the cutting is hard while the tip is still soft. The method for taking semi-ripe cuttings is just the same as for soft wood cuttings, above.
It is important to remember to take hardwood cuttings during the dormant season, when the plant is not growing. The ideal time is just after the leaves have fallen in the autumn or during late winter to early spring just before the new buds start to burst. To take hardwood cuttings you should choose a shoot that has grown in the current year. If you select a long enough one, you may be able to get more than one cutting from it. Remove the soft growth at the tip and cut the rest into sections 15-30cm long, depending on how many dormant buds there are. (Both roots and shoots will break from the dormant buds so the more buds there are, the shorter the cutting can be.)
You should make a sloping cut, just above a bud at the top and a straight cut just below a bud at the base – this way you know which way up you should plant the cutting. You can plant them into a trench outdoors but I always put mine into pots filled with a mixture of 50% horticultural grit and 50% multi-purpose compost. Water them in and leave them in a sheltered position in the garden (a cold frame is ideal but not a necessity). Don’t worry if nothing appears to be happening for some time after you have planted your cuttings; it usually takes a while for them to develop roots and shoots and it may be well into the new growing season before anything starts to occur.
You can take root cuttings from mid-autumn to early winter. Firstly, fill a seed tray with gritty compost, press it down slightly and water it. Then carefully dig up the parent plant, keeping intact as much root as possible. With a sharp knife cut off vigorous roots as close to the crown as you can, but do not remove more than a third of the root system from the parent plant otherwise it will struggle when you replant it. Cut each root into 3-10cm lengths (the thinner the root, the longer the cutting should be), place them on the surface of a prepared tray about 4cm apart, and cover them with a thin layer of compost. Put them in a sheltered position - again a cold frame is ideal - and in the following spring, when there are signs of growth and the cuttings are well rooted, pot them up individually to grow on.
A friend of mine has adopted another way of taking root cuttings which has proved as successful as any other she has tried. She prepares the cuttings in the usual way, but rather than putting them in seed trays, she simply puts them in a plastic bag with several handfuls of only-just-damp compost. She then gathers the top of the bag together, blows in it so that it is full of air, and then seals it with a wire tie. Then she just leaves it in a cool place until she sees shoots and roots appearing, and then pots up the little plantlets. Easy - and, she maintains, foolproof!