Young Apple Trees

Asked September 20, 2015, 9:54 AM EDT

I have six young Apple trees- 3 Cortland and 3 Honey Crisp. One honey crisp has black all over its trunk and is growing fungi of some type. A few of the other trees have spots on their trunks and seem to have bark becoming scaly. I had a few apples this year from each variety but not from all trees. We had a very late freeze which I think could have contributed to less fruit. I had leaf rollers early in the season which I treated with All Seasons spray. Can you help me identify what is going on with the trees. Wondering if I should remove the worst one- or if any can be saved- and what I should use as a preventative.

Oneida County Wisconsin trees and shrubs horticulture

1 Response

It's not really possible to make a definitive diagnosis from images, but I can make some observations and I'll suggest you contact a local extension office to see if someone can come and see your orchard. There seem to be several issues here and someone needs to see the context of the trees, what's going on in the branches and leaves etc. to really tell you what's going on.

For the one with the blackened bark, and seems to be split, the fungi growing on it are some indication of dead wood. This may be sign that whatever is stressing the trees has been fairly extensive on this one and is less likely to recover.

The problems on the other trees could be sun scald. In late winter when the air is cold a sunny day can warm moisture for a few hours which then freezes again, expanding and causing bark to split. This can then leave openings for other diseases or insects to get at the tree. Prevention is easy: simply use bark guards over the winter months.

There could be other insects at work, so I'd suggest use dormant spray oil in the late winter (a few weeks before bud break) and follow the directions for follow-up spraying indicated on the carton for your region.

Be sure to clean up all plant debris very carefully and destroy in the garbage.