The gap between summer and autumn is the ideal time for taking semi-ripe cuttings to propagate new plants.
Semi-ripe cuttings are taken from this season’s growth where the tip of the stem is still soft but the base is harder, which is roughly where the new roots will come from. Once you get your eye in you’ll start seeing loads of plant material that looks ripe for multiplying.
According the the Royal Horticultural Society website it is worth noting that, before mid-summer, propagate by taking softwood cuttings. And, after mid-autumn, the wood hardens, so take hardwood cuttings then.
Ten pointers for perfect cuttings
- Make sure you have a very sharp, clean pair of secateurs and a large plastic bag so the cuttings don’t dry out. Once you have taken them, keep them in shade (or the fridge) and look to pot them up as quickly as possible, definitely on the same day and no later.
- Cut a decent section of this year’s growth (the stem will be noticeably a lighter colour and more flexible than last year’s woodier growth). Keep it moist by placing it in the bag while you are taking other cuttings.
- To prepare the cutting use secateurs or a sharp knife and a cutting board if the material is too soft for secateurs. Cut the stem down to a length of about 10 to15 cm, cutting cleanly just below a leaf (this is where the plants new roots will come from) and take off the soft top just above a node (this is the slight swelling where next year’s leaves come from).
- Pinch off or cut the lower leaves from the bottom third or half of the stem. You’re looking to finish up with a stem about 10 to 15cm long.
- Some woody plants such as pyracantha, ceanothus and berberis take better with a small “heel” of older wood at their base. Pull down on a side stem taking with it a small piece of bark where it’s attached to the older stem, as this is where plants hold some natural rooting hormone. Clean up the very tip of the heel by cutting away any really straggly bits with a sharp knife.
- If you like, dip the bottom into hormone rooting powder and tap off the excess. This promotes root growth, but some gardeners do it and some don’t, it’s up to you.
- With evergreen large-leaved plants such as bay or Portuguese laurel cut the top leaves in half to reduce transpiration.
- Insert the cutting into a pot containing a mix of about 50 per cent sharp sand or perlite and 50 per cent potting compost or similar. Depending on the plant and size of pot, you can place a few around the outside of a single pot but make sure they don’t touch.
- Water well and let the pot drain.
- The trick now is to keep your cuttings free from frost, ideally a little warm, and don’t let them dry out. If you have a greenhouse or cold frame in your garden then that’s perfect but don’t worry if not. You can use a clear plastic bag secured with a rubber band over the pot which will act as a mini-greenhouse, then place it in a light frost-free spot out of direct sun such as a porch. Keep the compost moist at all times but let in air to circulate and remove excess moisture from the plastic bag when necessary.
By mid-spring your cuttings should have some roots and be ready to pot into larger pots or plant out into the ground. They will need “hardening off” for two to three weeks to acclimatise them to life outdoors. This can be done in a cool greenhouse, cold frame or outside covered with horticultural fleece. Let the young plants breathe by leaving them open to the elements on a warm day and protect them at night when temperatures drop.