SEMI-RIPE CUTTINGS

Take insurance cuttings now of frost-tender salvias, penstemons and verbena to grow on over winter

Tender and borderline hardy plants might not survive winter, so it’s worth taking cuttings of penstemons (pictured), bidens, pelargoniums, tender salvias and verbena now to act as insurance against winter losses. These plants can also become woody with age so taking cuttings every year gives you a supply of young plants that remain floriferous. Late summer is the perfect time to take semi-ripe cuttings, when the base of the cutting has hardened but the tip is still soft and bendy.

How to do it

Take cuttings from healthy plants. If you’re taking lots of cuttings, pop them in a clean plastic bag to keep them moist until you get back inside to pot them up. Find the right stems. Remove non-flowering stems just above a set of buds using clean, sharp secateurs or a knife. The cutting at this stage should be about 15-18cm (6-7in) long. Pop it in a bag while you take more cuttings, then pot them up as soon as possible. Remove bottom leaves. Trim each cutting at its base to just below a leaf bud – where the growth hormones are concentrated and roots will form. The final cutting should be about 10-15cm (4-6in) long with three or four leaves. Dip the base into hormone rooting powder and tap to remove the excess. Pot them up. Insert four or five cuttings around the edge of a 9cm (3½in) pot filled with a seed and cuttings compost, or 50:50 mix of Perlite and multipurpose compost. Water well and label. Place them in a bright spot out of direct sunlight or inside a propagator if you have one. Look for roots. When roots start to appear from the base of the pot, transplant each cutting in its own 9cm (3½in) pot filled with multipurpose compost. Overwinter in a bright, frost-free place and keep well ventilated to avoid moisture building up, which can cause fungal problems. Keep the compost fairly dry until the weather starts to warm up in spring, or the roots may freeze and rot.