Squirrel and rain damage in old oak

[Oaken Lad]

Hi, I live in Wales and we have a large, old oak near our house. I noticed today that squirrels have made/enlarged a hole in the flattish middle of the tree, where the main branches grow out and water can collect, and 3 young squirrels emerged from the hole. I don’t much like squirrels but my concern is that water hasn’t/doesn’t slowly rot the tree from the inside to enlarge the hole made by the squirrels. I’m considering putting sand into the hole and then a large stone on top, in the hope this would reduce the water damage and slow any internal rotting. Is this a good idea, could sand damage the tree? The oak’s about 400 years old and I want it to outlive me… Any comments gratefully received. 

[Squaredy]

3 hours ago, Oaken Lad said:

Hi, I live in Wales and we have a large, old oak near our house. I noticed today that squirrels have made/enlarged a hole in the flattish middle of the tree, where the main branches grow out and water can collect, and 3 young squirrels emerged from the hole. I don’t much like squirrels but my concern is that water hasn’t/doesn’t slowly rot the tree from the inside to enlarge the hole made by the squirrels. I’m considering putting sand into the hole and then a large stone on top, in the hope this would reduce the water damage and slow any internal rotting. Is this a good idea, could sand damage the tree? The oak’s about 400 years old and I want it to outlive me… Any comments gratefully received. 

Veteran oaks often become hollow, and this is not necessarily a problem.  To extend the life of the oak most likely a bit of reduction is likely to help it.  You won’t stop rot inside the trunk. 

 

 Post a couple of photos and see what other Arbtalkers think.  
 

[Mick Dempsey]

Water sitting in the cavity of a tree can stop rot as the fungi can’t spread in an anaerobic environment (or something like that) anyway, put up a pic.

[Mr. Squirrel]

On 27/04/2023 at 21:56, Squaredy said:

To extend the life of the oak most likely a bit of reduction is likely to help it.  You won’t stop rot inside the trunk. 

 

 Post a couple of photos and see what other Arbtalkers think.  
 

That’s a bit of a sweeping statement.  Reduction might prevent failures of any present structural defects but it’s an intervention which isn’t inherently positive for the tree. It won’t in itself extend the lifespan. 
 

If there are squirrels in the cavity then I’d hazard a guess that it isn’t full of water. Pics would be very helpful but sand, stones or any other form of filling the cavity are definitely not a good approach. 

[Squaredy]

As far as I am aware a very high proportion of the really old trees in the UK are trees which have been coppiced or pollarded.  It is generally accepted that with trees such as oak and ash it actually extends the lifespan.

[Oaken Lad]

Thanks for your comments. The tree branches were reduced in length about 15 years ago. I’m fairly sure there’s no short-term threat but, living and parking under a large tree as we do, I’m interested in how we can minimise any future risks.

Here’s a photo of the hole, with a few acorns to show that the hole isn’t a large one - but big enough to rear three squirrels in it.