Crab apple with a hollow branch

Joe Moshi

I noticed that there is a hole in the centre of this branch (hollow) of the crab apple tree. I inserted a stick and it seem the hollow part is some 1.5 inches in diameter, 6 inches deep and located some 8 feet above ground. Should I trim this branch below the hole?

I am attaching some pictures of the hollow branch.

Thanks

Joe

Attached Thumbnails

         

Eric Frei

We need a side on picture too

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TrevMcRev

And a far shot of the whole tree would be good too.

If it is only a small ornamental tree, which i suspect, then it may not mean it's really a hazard.

Joe Moshi

I have attached few more pictures. Thanks.

Attached Thumbnails

         

Eric Frei

The branch coming off the stem behind the hollow is epicormic growth, likely due to the branch being pruned and subsequently the hollow.

The tree needs to be pruned in more places than one branch, that epicormic needs some reduction perhaps. The branch you want to remove with the hollow I also reckon reduction and thin .... I wouldn't cut it right off.

Best bet wiould be to get an arborist out to do the prune, keeping cuts small so wounds seal over with growth, reducing weight and improving form.

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Joe Moshi

Thank you Ekka. What if I cut the branch just before the hollow, say one foot before? I can also do some minor pruning elsewhere to reduce weight and height? Thanks.

Eric Frei

Nope, that's a lop job.

1st, the decay is there to stay, further cutting makes it worse.

2nd, a decent woundwood roll has formed, which is mechanically and chemically stronger to stop the outward progression of decay

3rd, tree leaves are the food factory, the more you cut off the less defenses for the tree

Trees have hollows, they've dealt with that for eternity. All we can do is maintain the trees vitality so it can make it's own defences, wall off the decay as best it can. To reduce the probability of limb failure we carefully removed weight but also shape the growth of the tree so new wood is in a better location as the tree grows (ie, not out at the extremities causing leverage). If cuts are small then they will grow over, another big stub cut is a disaster.

There's an ole saying I have, "pruned so well you cant tell".

There's also antagonistic fungi which can help with decay, there's also mycorrhizal fungi which can help increase resources up take at the roots and there's also growth regulators which can slow the tree down a little, more compact and stronger wood with some decay defence added.

Improve soil conditions, mulch, do not fertilize and wella .... that is the way forward, now put the chainsaw away.

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Joe Moshi

Thank you Ekka. I appreciate the detailed explanation. The chainsaw will not be used.

Eric Frei

A handsaw should suffice.

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