After the bloom is over, cut the tatty leaves and spent stems of oriental poppies (Papaver orientale) to ground level. A fresh batch of leaves will regrow to fill the gaps.

If you planted large-flowered gladioli corms in the spring, use stakes to support the flower spikes as soon as they appear to ensure that they grow tall and straight. Keep them moist in dry spells.

For a big harvest of large peaches and nectarines, wait until the young fruits are the size of marbles, then thin them so they are 6in-8in apart. Keep the trees well watered in dry weather and remove weeds.

If you have outdoor benches, chairs or tables standing on the lawn, move them every few days; otherwise, the grass under the legs will quickly fade and ugly yellow and brown patches may form.

Readers’ questions

Can I sow chervil during the summer?

L Barlow, Leeds

Chervil is a herb grown for its feathery, bright-green, aniseed- flavoured leaves, which are usually chopped up and sprinkled over fish dishes, salads and soups. It is easy to raise from seed during the summer months. Choose a sheltered, lightly shaded spot with a well-drained soil and scatter the seeds in ¼in-deep drills: thin the resulting seedlings to 10in apart. In dry weather, keep the ground moist and remove any flowers that appear on the plants. The young leaves can be picked 6-8 weeks after sowing.

What is “skeletonising” the leaves of my gooseberry bushes?

S Grainge, by e-mail

In the late spring and summer, gooseberry bushes are prone to damage from gooseberry sawflies, which have green and black-spotted caterpillars up to 1½in long. They can quickly defoliate the plants, causing a severe reduction in fruit yields. To prevent problems, check the gooseberry bushes on a regular basis throughout the main growing season, especially the leaves in the centre of each plant, and remove and destroy any caterpillars.

gardenexpert@sunday-times.co.uk

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