- Check your greenhouse and conservatory plants for infestations of greenfly, and kill the pests when found. Clear up any dead leaves, as these will encourage diseases and attract slugs and snails.

- Cut back the stems of dogwoods, to just above the ground and spread a thick mulch around the plants. This will ensure a fine display of brightly coloured young stems next winter.

- ‘Amsterdam Forcing’ carrots can be sown in a sheltered, sunny spot with a light, stone-free, welldrained soil. Create seed drills ½in deep (at 6in-9in intervals), lightly moisten the base of each one and scatter the seeds thinly inside before covering with soil. Place cloches over the top and, once the seedlings emerge, thin them to 2in-3in apart; do this in the evening to prevent attacks by troublesome carrot flies. During the growing season, keep the area weed-free, watering in dry weather. Harvest the carrots in June.

- On a mild, dry day, redefine uneven lawn edges with a half-moon lawn-edging tool. This will give the grass a smarter appearance and prevent it from invading nearby beds and borders.

READERS' QUESTIONS

When should I plant out my autumn-sown sweet peas?

D Marshall, by e-mail

They should go out in the next couple of weeks. Erect a 6ft-high wigwam of canes, with their bases 1ft apart, in a sheltered and sunny part of the garden, then plant a sweet pea at the bottom of each cane. To deter slugs, surround each plant with a continuous circle of coarse grit. Tie in the plants loosely as they grow.

How do I grow summer purslane?

G Beeson, Cambridge

Summer purslane needs a warm, sunny spot with a light, welldrained soil. Sow under cover in mid-April, in modular seed trays or pots, and plant out when the seedlings are established. Alternatively, sow outside in late spring and early summer. The leafy shoots, which are ideal for salads and stir-fries, can be picked just eight weeks after sowing. Buy at victoriananursery.co.uk .

garden.expert@sunday-times.co.uk

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