Treating a damaged tree

There’s a big old tree in my back yard with a large hole about 40 feet up. Last week I had a tree service guy take a look at it. He said the tree was generally healthy but would benefit from some “treatments” over the summer. I gave him $350 in advance to do the work and almost immediately felt like an idiot for doing so.

So today he shows up for the first treatment and tells me that the tree needs more work than he thought. He wants to fill the hole with tar. Also, he says that the hole is infested with termites and carpenter ants, which need to be killed in order to protect the tree and keep them from spreading. He asked for another $400 to do the work. When I balked, he said he could do it cheaper by using diesel oil, instead of insecticide, to kill the ants and termites.

I haven’t been able to find information on the Web about using diesel oil for this purpose, but something tells me it’s a bad idea. Something is also telling me that the guy is playing me.

I’d appreciate any expertise, opinions, or experiences y’all might have.

Two years ago a different tree service told me the tree needed to come down; they wanted $3000 to do the job.

Without seeing the tree it’s impossible for anyone to judge. If the hole is small and well positioned in a robust species then an insecticidal treatment and sealing should cost no more than $200 in most areas. If the hole is large and has penetrated down through the heartwood in a susceptible species then I wouldn’t touch it for any amount of money for fear of an insurance claim that would blow out my premiums.

Unfortunately this is one of those situations where you either take the guy’s word for it or you get a second opinion.

One thing that it is odd that an insecticidal treatment with just diesel is substantially less expensive than treatment with insecticide. The cost of timber insecticides is negligible, less than $20 for this job. They are easier to apply than physical treatments like mineral oil. Really, the diesel treatment should either be cheaper than the insecticide treatment or $20 dearer at most.

On the bright side, by admitting that he can’t complete the job for the original price, the guy has voided any contract that you had. You can ask for your $350 back and walk away clear.

Thanks, Blake. To clarify, Tree Guy offered to treat with diesel for about $75 less than treating with insecticide. I didn’t know if diesel is a legitimate means of treating. From your post, it sounds like it is.

I’d like to save the tree, but have been putting the matter off for financial reasons. My neighbor hired Tree Guy to fell a big tree, and I asked him to take a look at my tree. I admit I proceeded unwisely. This is probably a matter that requires homework and a couple of expert opinions. I don’t have time for that right now. My current goal is to not make any further decisions I’ll regret.

I’d guess diesel or kerosene costs more than the insecticide. If you’re trying to save this tree to avoid the cost of having it cut down, then you’re in a bind. No one will guarantee the tree can be saved, so you may just need to pay for removal in the end anyway.

How close is this tree to your house, and what type of tree is it? Trees just don’t fall over for no reason, so if it’s alive now, it will be years before it becomes a danger to the house unless there are large branched overhanging. I think you should use inexpensive means to try to save the tree, and save your money for the cost of removal some day. $350 is way too much to pay for this.