15 gardening tips for August

Published on 3 August 2021

August means holidays are here, so take some time to enjoy your garden and reap the benefits of all your hard work throughout the year. There’s still plenty to do, though, and our top gardening tips for August will help you keep your garden looking great right through summer.

Gardening tips for August

Deadhead dahlias, daylilies and petunias regularly to keep them flowering through to autumn. Repeat-flowering roses should be deadheaded too, but leave rugosa roses alone to develop their brightly coloured hips for winter.
Camellias and rhododendrons need regular watering now, as they’re producing the buds for next year’s flowers.
Trim lavender once the flowers have faded, taking care not to cut back into old wood.
Prune rambling roses, removing one in three flowering stems, and tying the remaining stems into supports.
Give wisteria its summer pruning, cutting back all this year’s long whippy shoots to five or six leaves.
Pinch out the growing tips of cordon tomatoes, runner beans and squash plants. This will focus the plants’ energies on producing more fruit.
Trim herbs like thyme, mint and basil to give you the last flush of delicious new leaves before autumn arrives.
Strawberry plants will be producing runners now. Peg these down in the ground or in little pots, and they will grow into new plants for next spring. If you don’t need any new plants, cut the runners off.
Feed container-grown fruit and veg like tomatoes, blueberries and peppers fortnightly with a high potash feed to boost fruit production. Feed citrus plants weekly with a specialist citrus feed.
Net fruit to protect it from birds, pegging the netting down taut to stop birds getting tangled in it, and check it at least twice a day.
It’s time to start harvesting maincrop potatoes. Once their foliage fades, wait a week or two, then lift them carefully with a border fork. Cucumbers, courgettes, runner and French beans, beetroots, onions, carrots and tomatoes should also be ready to harvest now, as will plums, peaches and the first of the apples.
When the leaves of onions, shallots and garlic turn yellow and flop over, it’s time to lift them as well. Put them somewhere warm for a few days to dry out before storing them.
Sow salads like rocket, mizuna and lamb’s lettuce for a supply of tasty leaves through autumn into early winter.
Keep mowing the lawn, but raise the blade height in long dry periods to avoid stressing the grass. If you’re planning to sow seed or lay new turf in autumn, start preparing the area now to give the soil a chance to settle.
Finally, it might be mid-summer, but it’s never too early to think about next year’s garden. Spring bulbs will be in the garden centres soon, so start planning your planting now.