Horse Chestnut Leaf Miner, The nasty little so and so responsible for sending all our conker trees brown and making the leaves drop early. Some people will tell you that it doesn’t hurt, there’s nothing we can do about it, or it’s a waste of time trying, pretty much the same as they’re saying about ash dieback.
I’m going to come out and say all of the above is bullshit, and the same thing applies to ash dieback, but that’s for a different day and post.
It doesn’t hurt them.
Of course, it hurts, outside of them looking awful, in so much that the tree can’t photosynthesize properly, for the duration of the season. Trees that can’t photosynthesize properly become deficient in energy stores (food) get stressed and like us when all those things apply can get sick easier.
In the tree’s case Bacterial Bleeding Canker, the black tar-like spots on the bark, and fungi can become established, and with a weakened immune system the tree can’t fight back.
It’s a waste of time trying.
I suppose that depends on your outlook, but if we continue giving up on all of our trees, we’re not going to have many left, and then where does that leave us?
There’s nothing you can do.
If you listen to the chainsaw happy gang and a charity that’s very existence depends on donations for “at-risk trees and woodlands” then you’d be forgiven for believing that every tree disease is incurable, is going to wipe out all of the UK’s tree stocks and we’re all doomed!
Truthfully there are things we can do, some things are pretty easy do-it -yourself things and others aren’t
Clearing and either burning or hot composting the fallen leaves can help. You can hang a pheromone trap in the tree and catch the little beggars before they have a chance to lay eggs and cause problems. Soil improvement can help the tree absorb enough nutrients in the restricted timescale. Foliar treatments are probably the most effective and can either be a feed that makes the leaf thicker, preventing the miner from getting in, a specific pesticide that kills it, or a combination of the two.
So before we give up on our trees let’s look at the things we can all do to help them.