GARDEN GURU

Q I planted a common lilac in my garden five years ago. It always produces leaves but never flowers. It’s in a semishaded position that gets sun in late afternoon. What can I do to make it bloom?

Therese Neville

A I suspect your lilac (syringa) is a bit deprived of light. These shrubs are free-flowering when they get about six hours of sunshine a day and they do best in a sheltered spot that receives full sun. However, some varieties do take five years or more to bloom, so wait a while longer before deciding to move

it. In the meantime, don’t feed the shrub as it will promote leaf growth over the production of flowers.

Q I’d like to grow my own cut flowers and wondered what I could plant that will provide blooms all year round.

Janey Tindal

A Alstroemeria, cosmos, dahlias, lilies, sweet peas and rudbeckias are ideal for cutting from summer into autumn, while daphne, shrubby honeysuckle and witch hazel can be cut in winter. Set daffodil, hyacinths and tulips in autumn for flowers to pick in spring.

Q We have two jasmines and a camellia with leaves that are covered in black powder. What do you think it is?

Lynda Raithby

A It sounds like sooty mould, A an unsightly but largely cosmetic fungal growth secreted by sap-sucking insects. Wipe off with a damp cloth and control pests to prevent it coming back.