What disease does my Oak have ?

bestnh · #1 (**permalink**) 30-10-2009, 04:30 PM

Can anyone identify the disease affecting my Oak tree. Everything looks normal apart from the acorns.

charlieb · #2 (**permalink**) 30-10-2009, 04:40 PM

It's caused by a gall wasp - there will be a larva inside which causes deformation of the acorn and feeds of the tissue. It's nothing to worry about and doesn't cause any damage to the tree (oak is considered one of the most "susceptible" to gall causers, though nearly every other plant is also affected by other species of gall causers - Gall - Wikipedia, the free encyclopedia).

bestnh · #3 (**permalink**) 30-10-2009, 04:46 PM

Thankyou.

I will leave the tree alone.

Jim Ford · #4 (**permalink**) 30-10-2009, 06:03 PM

Knopper galls:

Andricus quercuscalicis - Wikipedia, the free encyclopedia

Jim

monkey · #5 (**permalink**) 30-10-2009, 11:32 PM

My oak has been dropping these mishapped acorns as well and they are very hard and spikey especially if you catch them wrong under your foot! I have also found the oak has not looked as well this year with the leaves looking very dry and brown particularly the lower branches and this started months ago before the autumn period. I noticed a lot of the oaks in the New Forest had the same so assumed it was not a disease and just possibly something to do with the weather this year?

Linda