Might be mildew, the english oak is quite susceptible to that when young. PH 4.3 is extremely acid though, is that really correctly messured?

This post was edited by Huggorm on Sun, Feb 2, 14 at 16:02

The soil tests were done in a laboratory from soil taken from my pasture next to the lane of oak trees.

The type of grass that is growing in the area also suggests acidic soil.

I thought that Oak Trees thrive in acidic soil, will read more about that.

I will treat the trees for mildew.

Thanks

Most oaks like acidity, but probably not QUITE that much. FWIW English Oak is one of the more alkaline-tolerant IIRC.

Does look like mildew, though.

You should have seen one of mine, I have 3 from the same source. The 2 uphill looked okay, but my downslope one looked worse than yours, it had brown edges and a bagworm infection. I need to use BT next season. I just let them defoliate it, as it was the end of the growing season by then anyway. Is your area humid enough for the mold? My soil is mostly neutral so I can't help much with the PH thing, but, I have a book that mentions England as being calcerous in many areas and it is of course the "English oak". I am basically repeating what hairmetal said about PH.

Mildew on Quercus robur (English Oak) is usually a sign that the tree is under stress. Here in the Netherlands you see it when the summer is really dry. Last summer we had a very dry summer with little rainfall. All the English oak trees (more than 60 years old) in my street where affected by mildew.

I have seen English oak trees grow well in reasonably acidic soil but as said here above a PH of 4.3 is extremely acidic.