[keeffa]

I was wondering if any of you could give me some advice about the state of this small tree I planted in the spring. It has a kind of mildew on the leaves and I'm worried it might die off. (Sorry the pics aren't great)
Thanks in advance.

[James Kilkelly, was GPI.]

Welcome keeffa.
Looks like a touch of powdery mildew.
You can spray against it with a fungicide containing the active ingredient myclobutanil such as Bayer Garden Systhane Fungus Fighter.
At the end of the season collect and destroy all fallen dead leaves that might harbor the fungus.
If applying an artificial fertilser, you should select one specially designed for trees and shrubs.
Ensuring the plant is well fed will help it resist diseases.
Avoid at all costs high nitrogen fertilisers, as these encourage soft sappy growth that is more easily colonised by Powdery Mildew.

A quick video on the fungus here for you to have a look at Powdery mildew video.

[keeffa]

Yes, that is what it looks like. Thanks for quick response, will try the fungicide and fertiliser.

[James Kilkelly, was GPI.]

Let me just clear this up a little.
I am not saying your tree looks like it needs some fertiliser, but if you do aplly some in the future you should avoid at all costs high nitrogen fertilisers, as these encourage soft sappy growth that is more easily colonised by Powdery Mildew.
Go for the fungicide though.