READER’S QUESTION

OUR hollyhocks look awful. The leaves have scabby marks on their undersides and seem to be dying prematurely. What causes this?

T. Baron, Suffolk. THE problem is Hollyhock Rust, a serious fungal disease. The first signs are brown or rust- coloured pustules on the undersides of the larger, lower leaves. The disease spreads until much of the foliage is damaged. The weakened plant then flowers poorly and can even die.

Hollyhock Rust is most likely during cool, damp weather. There is no chemical cure but affected plants may partially recover if the weather becomes warm and dry.

In future, try growing varieties resistant to rust, such as the Halo Series.