if the interior of the tree is rotting... there is NOTHING you can do.. but take it down ... the whole tree is dying.. not one side ...

the problem being.. we cant see the extent of the decay ...

will it fall on anything important??? .. without a scale.. but looking at the trunk.. i am going to guess.. this thing is 50 to 80 feet tall ... and physics dictates.... it will achieve maximum velocity on its way back to earth ....

ken

Yoiu say your cottonwood tree has holes in the trunk and one side dying? Hurray! It's just a cottonwood. I suppose if cottonwoods were the only kind of tree, I'd be a big fan of cottonwoods, but since they aren't, I'm not.

None of the stuff you propose-grinding away at the decayed area, getting rotten material out, spraying anything in there, screening, etc, is a part of modern tree care. Trees evolved to handle wounds and decay quite nicely thank you, before us monkeys came along. Wouldn't it be amazing if a whole group of organisms evolved needing help from other organisms that weren't yet even around?!?

Ken is asking about targets. Are there any? If so, this may be a good candidate for removal. If it's out in the clear, in the woods, or just some random spot where people rarely go, cars don't get parked, etc....you could leave it to decline, thereby providing much wildlife habitat as a "snag" or standing dead tree.

+oM

My first impression of the holes were that they were made by woodpeckers looking for insects. I have seen Pileated Woodpecker do exactly that kind of damage. At 16 to 19" long, and wing spans of 26 to 30", a Pileated Woodpecker is an impressive bird. It is fascinating to see them work on a tree, and realize what a bird can do to a tree.

If it is insects under the bark the birds will control them for a long time, but the life of the tree may prolonged with insecticides.

If it is insects, the tree will probably be standing when you sell you property.

Reminded me of pileated holes too, but so low on the trunk? Never saw that before.

To each his own, but IMO, spending one dime on protective chemicals for this-or any other cottonwood-is a certain species of madness.

+oM

This is a picture I took of one when we were in Indianapolis. It is difficult to get one of these guys when they are not moving.

As you can see he made holes in this tree in about the same position as the original poster's tree.

My end vote is the same as the other guys. If it is near your house or a car you like start getting estimates for removal.

If it is on the back 40 I would LOVE to experiment in that tree with some sealers like you are thinking. IMO all the structural wood inside that big tree is just like a big cottonwood 4x4 and if I want a 4x4 to last outside on my deck I darned well better treat it. Now you do have to clean it and dry it previous to treating it. Also lord knows what is best to use. I'd stoo coating whatever well short of the live outer layers of the tree. Even though my neighbor's silver maple obviously is none the worse for encapsulating that metal fence post no need to temp fate by letting the live layers of the tree contact a chemical.

If large parts of the canopy did not sprout this year that is all for experimentation though. I just can't see the vascular portion of the tree recovering even if you somehow stop the rot.

When I bought my property, the first thing I did was cut down every cottonwood on it. It makes fairly decent firewood if you can cure and completely dry it. Left on the ground it decays fairly rapidly here if it doesn't take root and sprout.
Mike

Thanks to everyone who responded. That tree is situated at the edge of a 45 degree bank down to the lake 50 feet below and the edge of a gully about the same depth and is holding the corner of the cottage yard from falling so I want to either keep it alive or plant something else either in its place or under it for now that would continue to hold the bank(s). Any suggestions for something that is hearty in the NY finger lakes region (microclimate is warmer due to the lake surrounded by vineyards), grows fast enough to establish roots fairly quickly, might survive as an understory tree for a while, etc? The tree is not close enough to any structures or cars but if it went and took the roots with it, it would be a major erosion issue.

Thanks,

Greg

Weeping willlow - fastest. You will outlive it though if you drive carefully.

Bald cypress - pretty fast and will last.

Metasequoia - Dawn Redwood would be a sort of experimemt. I think zone 5 slows them down. Here they seem a little faster than their cousin baldcypress. They last as well.

gnsmith, don't "buy" trouble/expense/worry if you don't have to. If it's not threatening to anything, don't do anything.

If you like, digging relatively gently into the rotting area w/your hand or a claw hammer or chisel won't hurt anything as good wood won't be removed that way -- only stuff already rotted, and it would give an idea of the extent of the rot. Done this many times on forest trees where I used to live.

Seems to me the problem is this is a codominant tree trunk. The side that is dying probably has lots of rot in it. My call would be to have the tree removed as cottonwood has pretty soft wood. It's not a question of IF it's WHEN the tree will come down. That's why cottonwoods are not very desirable trees around homes.

You may do better to control the erosion with a good groundcover.

Anybody still thinking that human intervention-of any kind-can do a darn thing to delay/slow down/stop a vertically-oriented column of decay in a tree would do well to brush up on their CODIT-that is, compartmentalization of decay in trees-the model developed by Alexander Shigo in recent decades to explain how trees are able to deal with injuries. The wall that is formed to stop such spread is the weakest of the 4 walls, and no amount of slopping on any man-made product is going to do one thing to change that. Then, to top it off, we're talking about a weak compartmentalizer-cottonwood! Talk about wasted effort.

This isn't some high-value white oak, or even some mid-value tree with sentimental value. It's a low-value cottonwood, which should be allowed to fail on its own-if there are no targets present-or taken down post haste if there are. No other inputs can be justified.

+oM

Figure out a better erosion control system for that area and get bids on it, because by the time you see die-back in a tree it's usually seriously decayed under the bark. Deep-rooted shrubs on the bank, retaining wall ... something.

I doubt you could get new trees big enough for erosion control before a storm takes out the cottonwood. And it's better to take it out than let the wind do it for you. For one, you can keep the roots intact, while a wind-blown tree usually falls over roots and all.

Whether you choose to take it down or not, it might be a good idea to get as much groundcover established this Fall as you can.
I see you already have Vinca minor.
I've cut brush to encourage groundcovers. Brush usually re-sprouts, but it sure gives a boost to the groundcovers in the meantime.
Mike