Garden Guru

QOver the past few years I have found strange, distorted growths on the shoots of an old azalea. What are they and how can I get rid of them? Lynn Prescott

AIt sounds as if your plant is being attacked by azalea gall, a fungal disease that results in abnormal, fleshy growths. There is no chemical cure for azalea gall so pick them off and destroy before they turn white and release more spores.

QLast year I moved into a new build and planted silver birch trees in poor soil that contains builders’ rubble. Surprisingly they are thriving. However, I want to create a raised bed. Will the trees tolerate having soil being piled up around their trunks? Hilary Hinds

ANo. Damp soil will soften the bark and lead to rotting. As the trees have only been in the ground a short time, they should be OK to transplant. Wait until October, then lift carefully out of the ground. Heel them into soil elsewhere, build your bed and replant.

QI have an infestation of red ants in my lawn. I’ve tried various powders, but with no success. What do you suggest? Dave Glavin

AIt can be difficult to eradicate ants’ nests. Some gardeners find that using a biological control works. A powder containing predatory nematodes is added to water and then sprinkled on nests. £12.99, Nemasys No Ants (nematodesdirect.co.uk).