READER’S QUESTION

I HAVE grown perennial asters before but have never had such a serious problem with mildew. It is creeping up the stems. What’s the problem? Mrs V. Cole, Swansea. MIchaelMas daisies (left) are wonderful perennials but many are susceptible to this disease. With few effective fungicides available, it’s wiser to replace disease- prone varieties with resistant ones.

asters that resist mildew include varieties of Aster novae-angliae, such as alma Potschke (right), harrington’s Pink and purple red september ruby. The latest to flower,

Aster lateriflorus, also stays clean and brightens November with red- centred lilac blooms.