This week's gardening tips

Wasps

Wasps are useful in the spring and early summer as they eat garden pests, but this is easily forgotten when their food sources are no longer around and they start on your fruit. We’ve not had much success when we’ve put traps near our bushes to protect the fruit, as the fruit is more of a draw than the syrup in the traps. Through August, the most vulnerable fruits are plums, figs and mulberries, so remember to be very careful when picking them, in order to avoid stings.

Raspberries

Cut back the old fruiting canes of your summer raspberries almost to the ground, to make way for next year’s, but take care not to damage the new ones as you do so. Keep only the strongest new canes, and not more than six to nine per plant; remove all the thinnest ones to avoid overcrowding. Tie them to your supports you won’t need to feed them if they’re near the height you want, as anything over 6ft will have to be trimmed down in the winter to prevent wind damage. It’s not a bad idea to mulch them, however, in order to retain the moisture. Raspberries will continue to fruit for eight or nine years, but replace old plants with new stock. New varieties are being bred with better disease resistance a bonus for the organic garden.

Hedges

If you leave trimming your hedges until August, you’ll keep that just-cut look for the rest of the year, as it’s now late enough for the plant not to re-shoot except privet, of course. Dwarf box and other such small-leaved evergreens have to be cut with very sharp shears or electric hedge trimmers, as you will be cutting through a lot of leaves; blunt blades chew the leaves and their edges turn brown. Don’t cut on very hot days as the sun will scorch the newly exposed leaves. It helps to spray the hedge afterwards ideally with rainwater. It’s a good time to trim your yews, but be sure that you’re only cutting off this year’s growth; if you cut into the old wood, it won’t shoot until next year. If it’s practical, prune and shape the stems of your larger-leaved evergreens, such as bay and laurel, with secateurs, for a neater finish.

Herb cuttings

Now is a good time to take cuttings of shrubby herbs, such as rosemary, sage and thyme. Plant a few freshly picked tips into a 3in pot and keep in a mist propagator, or, if you don’t have one, cover with a plastic bag pierced with a few holes, then leave in a well-lit spot, but out of direct sunlight. If you replace your herbs every few years, you will keep them vigorous. Creeping thymes root as they spread propagate by digging up the new growth from the plant’s edges with a trowel, pot and keep out of the full sun while they root into the compost. Philip Maddison is head gardener at Harrington Hall, Lincolnshire (www.harringtonhallgardens.co.uk)