Mysterious hole in bark, and manky bark (oops, my bad)

[jxm]

Hi,

I've just noticed this large hole in the bark at the base of my plum tree. Any idea what might have caused it, or if I should be worrying?



Rather suspiciously there is a similar hole at the base of an apple tree a few metres away (right at the bottom of the picture)...



On a slightly different matter... when I first planted the trees I put a kind of plastic wrap thing around the trunk to stop my annoying cats using the trees as a scratching post. This worked very well and I just left it there (it expands as the tree grows so i thought no more about it).

However, I've just taken it off and on the apple tree in particular the bark has gone totally manky. No doubt all the rain got underneath and get it permanently damp, but the question is what do I do now?

The picture below is exactly the same tree as the 2nd picture, in fact the photo below is about 1-2 inches above where the picture above stops. You can see the difference in the colour of the bark - no that's not a difference in the photo, it really is that different in colour!



It's a really yucky brown colour and the bark is just flaking off. Will the tree survive like this? If there something I can do to repair it (some gooey stuff in a can from the local garden centre maybe?)

Despite the manky bark the tree has grown well this year and is covered in blossom. It would just be a pity if it suddenly died as it only started producing lots of apples last year...

[FB.]

The plum damage looks like a wound - probably caused by chafing of the guard.
It'll probably be OK, but keep an eye on it to see whether the wound starts to look nasty or expands in size rapidly.

If the trees are growing well, they are probably OK.
If you have caused damage, I doubt that there's much that you could do to reverse it now anyway. Covering the wounds with a sealant won't get rid of all the muck and moulds that have had access in the past months/years.

I have occasionally seen crown rot and collar rot resemble the third picture. On a young tree there is no cure, with death occuring within a couple of years; often the tree collapses and dies shortly after a stunning blossom display.
A further few pictures taken slightly further away would be useful. If you could picture from the soil to an inch above the graft of the apple tree, it would help to rule-out collar/crown rot.

Putting your location into your profile could also be helpful....as would an idea of your soil type (certain soils are more prone to crown rot).

[jxm]

ok, here's a view of both the damaged areas...



...hmmm... just noticed from the photo a rather significant bend in the trunk, right where the wrap started - I wonder if that was like that before?

and a wider shot of the whole tree...

[FB.]

Hmmm.....it's difficult to tell whether it's a bark infection or whether it is simply chafing of the tree guard and lack of sunlight bleaching the bark.

If it is a bark infection, it is now so extensive that the tree will not survive, no matter what you try.

So I suggest leave it and hope for the best. If you wish, you could try a spray of Bordeaux mixture on the damaged area (please read the label!), which is the usual treatment to prevent canker establishing (but it can't cure once infected).

I would also suggest getting those plastic straps off the arms of the espalier (and if support is needed, put some in different positions) as they will eventually cut into the bark and cause more problems.

Which variety do you have? Some apple varieties are a lot tougher than others.

[jxm]

Thanks, I'll see how it goes then. It's Discovery Apple.

[FB.]

Hmmmm.....

A couple of years ago, I lost a Discovery (among others) to collar rot, with the infection entering at the graft and running up the trunk, much as your picture.

A feature of my own trees which died from collar/crown rots was that the wood under the peeling bark was soft, like cork (apple wood is usually reasonably hard; the variety "Blenheim Orange" used to be used for making wooden wheels and cogs for machines). See whether your trees' wood is soft like cork, by using your thumbnail. If so, it is probably incurably severe collar rot that will kill the tree within a year or two.

Here's a picture of one of my trees, which died from crown-rot/collar-rot/canker: