Today I managed to do major damage to my lawn. I was on my deck applying a coat of a deck sealant (Penofin Ultra) when I knocked the 5 gallon container off the deck and onto the lawn. The top was not on it and it spilled. I lost probably 2 1/2 gallons of the stuff.

The yard slopes slightly downward from the deck, but I happened to spill squarely onto a sprinkler head, which over the years had caused the ground around it to settle slightly into a bowl. I never even noticed that this had happened under the grass, until today. It probably saved a larger part of my yard from damage.

My first thought was that I'd have to wait for the sealant to dry and dig out the affected area, but then my wife pointed out that the deck, and the spill, was under the drip line of a large mature Ash tree. I called my local garden center and the only thing they could suggest was that I get that soil dug out, about 12" deep, and do it immediately.

So that's how I spent my Labor Day, digging out a 6x4 foot section of lawn carefully avoiding bigger tree roots (and there were some big ones), until the dirt no longer smelled of deck sealant.

I guess this is more a tale of woe rather than a question. This sort of thing has to happen. Why can't I find any references to it online anywhere? I joined this forum because it seemed like a good place to start.

If it happens to you, you need to treat it like a toxic spill. If the product is thin (like paint thinner, or gasoline), it will penetrate deeply and quickly. Penofin is oily and not as thin, but I was amazed at how it travelled along tree roots and the sprinkler pipe, and how deep it went in a few minutes. The lawn in that area is a big hole now (it's in the front yard). I can only hope I saved my tree.

I'm going to be filling the hole tomorrow, though I wonder what I'm supposed to do with about a dozen wheelbarrows full of contaminated dirt (currently sitting on a tarp on a brick patio). I wonder if the sealant will just dry out like it would if it had been applied to the deck, and after some time (a week? a month?) the dirt would be usable as fill.