It is a simple, but magical, act: take a little bit of stem and, with a few careful cuts, create a new plant. That magic, the ebb and flow of hormones and auxins, is on your side: once severed of its root, the plant is desperate to take hold again. All you have to do is give it a go. Right now, the window for semi-ripe cuttings is drawing to a close, but it is not shut: this weekend, for 15 minutes’ worth of effort, you can take those tired lavenders that have become leggy, or that woody rosemary, and strike a few cuttings so you have new plants for spring for free. Hyssop, thyme, bay, sage, lemon verbena, rue, scented pelargoniums, penstemons and verbenas are suitable for semi-ripe cuttings.
These cuttings are taken from sections of stems of this year’s growth. Ideally, these sections should not be flowering and they need to be woody or firm at the base and soft at the tip. You are after the middle section, which is “ripe” for striking roots. You will need secateurs or a knife, some seed compost with a little extra grit or perlite for drainage, a plastic pot and a clear plastic bag. You will also need a warm, light windowsill on which to put the cuttings, or a greenhouse – either way, they must be kept out of direct sunlight.
Once the stem loses contact with the roots, it starts a rapid process of wilting, so cuttings should be taken in the morning or evening, but never in midday sun. If possible, you should either plunge the cuttings straight into cool water or put them in a clear plastic bag, sealed shut to retain humidity. Kept cool, cuttings can be stored for 12 hours this way.
Your knife or secateurs need to be very sharp and clean– this is surgery, not a hack job. Take cuttings that are 10-15cm long, cutting just below a leaf node (where the leaf appears from the stem).
Next, remove the lowest set of leaves, as well as the soft tip. There should be about four leaves remaining. Insert the cuttings into the compost to just below the lowest set of remaining leaves and cover with a clear plastic bag, so they stay moist. Keep the compost damp, but remove excess moisture, if necessary; too much, and you will get mould. You will know the plant is rooting well when you see new leaves appearing. When this happens, remove the plastic bag. You can pot up once the roots start poking out of the drainage holes. You will have to keep the cuttings somewhere sheltered and frost-free over winter; a cold frame is ideal, even if it is just fashioned out of some bricks and glass by the back of the house.
