crab apple

[liz budd]

We have a crab apple tree which for 3 years has been suffering from brown leaf drop from June onwards. We have had it sprayed with pesticide several times to no avail. It's about 30 feet, but we dont know how old it is. How can we tell if it's dying or will recover?

[snick]

There are a number of possible causes. Are the fruits also scarred? If so it could be apple scab which works on the leaf and fruit. This requires treatment with a fungicide rather than insecticide. Another possibility is a bacterial canker which often results in gum leaking from stems. Again this needs treating with a fungicide. If you want to keep the tree it might be worth cutting it back hard this winter to rejuvinate it and giving it a good feed and see if that does any good.

[liz budd]

When should fungicide be applied?