repairing a tree with hole in it

[Danny]

Hi, I have a tree in the yard that's very large and close to the house. It's still living and a viable tree. I have many very large trees close to the house that could fall on the house if left long enough or if they were to be ravaged by disease.

The one in question has a hollow section near the ground that has some insect damage and a resulting hole in the trunk, but right now it's growing great and I'd like to fix the damage if possible to stop any further damage from happening. I'd like to do this so that I either don't have to look at taking the tree down in some years or having it fall on the house due to disease.

I saw a product sold at the various home stores. It was some kind of pruning sealer. On the back it tells that if you want to seal a cavity in the tree to do something such as fill it with xx amount of portland cement (I may be wrong on specifics cause I don't have the product in front of me, but maybe some of you know what I'm referring to) and put it in the damaged portion of the tree (pack it).

Does anyone think that this is a good idea? Has anyone done this sort of thing before. I know that the proper thing to do would be to call a professional, but I have so many jobs at hand to do that anywhere I can save a buck or two will ultimately help me with some big projects that I'm going to have to do/have done.

What about the insects/insect damage in the tree. Do you just seal that over, or do you do something to it before you pack the cavity with that stuff.

If I can just save the tree a few more years to buy time as compared to if I'd done nothing, I'd be happy. by then, I'd have more of the stuff done that's a higher priority.

Thanks for your help,

Danny

[Jeff Wisnia]

I've done the cement thing and it's worked for me. Regular premixed "mortar mix" is what I've used, though "concrete mix" should work well too.

If the hole is bigger than an apple and shape of the tree and hole will accomodate this, it helps to drill holes and stick one or more pieces of

3/8" or 1/2" "allthread" rod through the sides and across the inside of the cavity. Put nuts and washers on both ends of the rod and saw the excess off. That will give the cement plug something to hang onto.

Spray the inside of the cavity with sealer before packing in cement.

A light spray of sealer on the concrete (and the hardware if you installed it will make them blend in pretty well.

I use automobile undercoat spray as pruning sealer. If you buy it at a discount auto parts store it costs about half what they charge for spray pruning sealer, and as far as I can tell it seems to work just fine for that application.

[Tom Miller]

Why Fill a Hollow Tree?

Filling of hollow trees, a process called "cavity filling," was practiced by arborists for many years. Thanks to modern research, it has been discovered that cavity filling is not needed to support orimprove the health of hollow trees. Tree experts have found that cavity filling with cement can actually damage a hollow tree.

According to Bob Rouse, Staff Arborist at the National Arborist Association, "the column of cement created in the tree by a cavity fill doesn?t move, just like a column on a building, but the tree is always moving. It sways with the wind constantly. The rubbing created by the swaying tree and the solid column of cement further damages the tree."

Decay organisms, such as rot fungi, that created the hollow in the first place are able to take advantage of the new injuries created by the rubbing and invade the healthy tissue of the tree. Rouse adds, "If that wasn?t bad enough, the cement holds moisture, creating a favorable environment in the filled cavity for the decay organisms!"

Tree experts explain that it is much the same as when carpenters place a vapor barrier between a house?s foundation and the wooden sills. If they put thesills directly on the concrete foundation, the wood will rot rapidly. If you place cement in a tree cavity, it will speed the wood decay!

If cavity filling is desired for aesthetic reasons, there are some new synthetic foams that can be sprayed into the cavity by professional arborists. These materials will bend with the swaying tree, but Rouse warns, "There is really no reason to fill a cavity; it doesn?t improve the tree?s health and doesn?t offer any added support. If structural support of a tree is required, a professional arborist will recommend cables, braces, or tree guys, not cavity filling."

Tree experts recommend:

• not filling cavities with cement;

• supporting, if required, with cables, braces, or tree guys;

• if you must fill a cavity, have a professional arborist install a synthetic foam fill.

-- National Arborist Association

[Jeff Wisnia]

I stand corrected.

I guess my knowledge is out of date now, but that's the way I *learned* to do it, clearly it was before that "modern research" was conducted.

Jeff

[Chet Hayes]

If it were my house and a tree like this was growing close to it with a hollow section in it, I wouldn't be trying to patch the tree up, I'd have it removed before it falls down and you have a real problem. Once problems like this start, it can be difficult to predict the extent of the damage inside the tree. They can still be alive and come down in a storm. It's just not worth the risk.

[Phisherman]

Years ago advise was to fill the void with concrete. Today, arborists recommend keeping the void clean and a healthy tree will eventually repair itself. Other than that, it may be worth having an arborist take a look at it. You can call your local cooperative extension.

I had a damaged sycamore tree and a damaged hickory tree, both with large holes >Hi,

[Dan]

Iowa State University arborists give the same advice. Trees are better at healing themselves than we are.

[Tom Miller]

I had to unlearn it too, Jeff. Don't feel lonesome.

[Harry K]

Yep. Sealing up the hole or even filling the hole is not stopping the internal rot. That tree will fall eventually. It may come down tomorrow or 10 years from now but it will come down.

Harry K