Garden Guru

QI have six self-sown marsh orchids in a 12in pot, which are competing with weeds and grasses. When and how should I remove the seedlings? Garry Hughes

AIt’s best to transplant marsh orchid (dactylorhiza) seedlings when dormant, preferably in the autumn. Mark their positions so you can find their tubers later. When ready, decant the rootball from the container and carefully remove the tubers. Replant, 2½in deep in small pots filled with 70 per cent multi-purpose compost and 30 per cent horticultural grit.

QI live in a row of houses and a wild clematis has grown across the back of several gardens, stifling trees and shrubs, and has now reached mine. Can I stop this parasite? Moira Gregory

AAptly known as traveller’s joy, Clematis vitalba is famed for its ability to spread long distances. I would suggest that you curtail its spread by pruning, using long-handled loppers or extendable pruners if necessary. Try to get your neighbours to do the same.

QI’ve tried growing tomatoes in pots this year. Some of the fruit has turned black at the bottom. Is there a cure? Mia Anderson

AThis is known as blossom end rot, a problem caused by irregular watering. There’s nothing you can do to cure infected fruit but the remaining ones can be saved by watering twice a day to ensure that roots never dry out.