By Sally Gregson.
August can be a disappointing month. Despite weeks of drought, inevitably it seems to rain just when a barbecue is planned. But that’s just the perfect time to take summer cuttings of half-hardies for next summer. All those expensive flowering perennials that are filling the pots to overflowing are full of good cutting material just ready for the secateurs.
Cuttings taken in August, after you have come back from holiday, will provide lots of stocky, healthy plants by September to over-winter on a cold windowsill, in a porch or in a frost-free greenhouse.

Prepared cuttings. Well-rooted cuttings. Pot up the cuttings.

How to grow cuttings
Remove a growing shoot, about 10cm long, preferably without flowers, just below a ‘node’ – the point at which a side-shoot or a leaf joins the main stem. Cut back the ‘snag’ you have left on the plant to a lower node. Remove the lower leaves and any flower-buds from the cutting, and the growing tip. Dip the base of the cutting in hormone rooting powder, tap off the excess, and insert it around the edge of a shallow pot filled with a mixture of potting compost and sharp grit (50:50). Label the cuttings with the name, number and date taken; water it well to settle them in; and drop the pot into a clear plastic bag. Blow into the bag, tie up the top and place it somewhere shady where you can keep a watchful eye.
Open the bag daily. Eventually, once the cuttings look perky, keep the bag open. Then little by little remove the bag, water the cuttings regularly and place the pot somewhere less shady, although not in direct sun on a greenhouse bench.
After a few weeks they should have rooted through the base of the pot. Tip them out and pot the cuttings individually into small, 9cm pots and place them somewhere visible so you can keep an eye on the watering.
If the cuttings don’t root, you still have time to take some more. If they only have small roots by the end of September, it’s wiser to keep the cuttings in the propagation mix somewhere frost-free, until next February. If cuttings are given too rich a life between November and February, they will make tall, sappy growth that is prone to fungal disease.
After February they can be moved into larger pots, still keeping them frost-free. They will be ready for planting into their final pots for the summer by May.