Grass problem: Dry patch

[crbd98]

Hello All,

Some years years ago, I removed an above ground pool (approximatelly

30'x18')from my backyard and planted a lawn instead. I used a Pacific Northwest mix from Scotts (we live in OR).

As the years passed, I noticed that the grass planted in that area would grow drier and thinner. In very warm summers, it would basically go dormant, despite regular watering, while the surrounding areas (which were planted at the same time) would be looking just fine. Two years ago, I covered the area with a thin layer of top soil and reseeded it. The results were good and it lasted for a year. Nevertheless, the grass went dormat again this year.

The problem might be related to the fact that there was a layer of sand underneath the pool. We brough good soil and rototilled the area but we might have underestimated the thickness of the layer of sand.

I would appreciate your comments and suggestions to ammend the problem.

Thank you CD

[Warren]

How deep was the pool? If we're talking about a typical swimming pool with depths of 4' to 10', the sand that was under the pool would be a non-issue. (I'm assuming that when you say "removed" you mean you took out the concrete, and didn't just fill in the pool.)

And what was used to fill in the remaining hole after the pool was removed? Certainly you couldn't afford good quality soil for the entire depth. Assuming that you have some fill, and then some good soil on top of it, how deep is the good fill? Was organic material added? Or are you totally depending on chemical fertilizers?

BTW... It's entirely normal for a Northwest lawn to go dormant in the summer. The only part of my lawn that doesn't is part of my front lawn that's under a big tree. There's a part of my front lawn, a small

8'x8'x5' triangle, that falls outside of this shade, and just keeping it somewhat green takes as much water as my parents used to keep their whole 1000 sq. ft. lawn in Wisconsin green. And it still doesn't look as nice. Could it be the surrounding areas that aren't going dormant have more shade?

[how]

Don't do lawns myself but compaction might be a factor. HTH -_- how no NEWS is good

[crbd98]

Hello Warren,

The pool was above ground, not inground. However, It was sitting on a

1-2 ft deep bed of sand. I did not remove the sand, just brought more good soil and rototilled it. I thought it was enough but it sure wasn't because that is the only spot that is dry and dormant despite watering. The problem area is about 600 sq. ft. The rest of my approx. 4000 sq. ft lawn is doing all right.

I'm wondering if there is a way to amend the problem without having to dig the area, remove the sandy soil and put good soil....

Thanks CD

[Warren]

With the sand mixed in the soil, the drainage is much faster over this patch than the rest of the yard.

Removal might not work, either. The soil you replace it with would probably still be different than the rest of the yard. Time, as in multiple years, may take care of that. Or not.

Rather than removing, and then trucking it away, spreading it around the whole yard may help create more similar conditions, but you'd have to work hard to get an even distribution, and there still is going to be a difference in that spot for a few years to come. Either way, adding organic material over the whole yard each year will help speed the number of years until you can't tell the difference.

You'd be a year ahead of the game if you had trucked away the sand last year, but even if you had, you'd still notice a difference this year. And we're probably talking a half a decade or more before other people won't be able to see the difference in the peak of summer, and a decade before you can't see the difference.

You sure you want that big of a lawn? Do you need a play area for yourself or the kids? Will it be serving a function? If not, considering the amount of time and work it'll take to get an even looking lawn, this might be a good time to consider some island beds. 4000 sq. ft. would make one great garden with islands, and paths, and water features, and other little surprises.