Summer is now over in the United States, prompting many of us to remove our pools. But wait—what’s that smell? If you look beneath your pool, you may notice that the grass beneath it has literally turned into crap. What makes dead grass look and smell like feces? Is your lawn dead because you wanted a pool? This article will answer all your questions and more, so put on some nose plugs and read on.
The Death Cycle of Grass
When you put something on top of your lawn, the grass beneath it does not die immediately. Instead, it goes dormant. Grass can remain “asleep” for 2–3 weeks without sunlight or water. After that, it begins to die.
Grass composts itself very quickly once it dies. The result is exactly what happens in your compost bin: the organic matter rots and turns into crap. The high nitrogen content in your grass makes it extra-smelly. It helps to plan around this event when buying a pool.
Is There Anything I Can Do?
Unfortunately, if you put anything atop a patch of grass for a long enough time, the grass will eventually die. If your above-ground pool is not easy to move, it is better to replace the ground beneath it with something like concrete or stone before you set it up. (Do not use mulch beneath a pool.)
If you have an inflatable pool, the best solution is to move it around occasionally. You can put a tarp beneath your pool to make it easier to move. Ideally, move your inflatable pool daily, but the max is every two weeks.
Now That It’s Dead, What Do I Do?
You’ve removed your pool, revealing a brown, stinky mess. What now?
The only thing you can do about your ex-grass is “wait it out.” It’s not worth the extra effort to deodorize a patch of grass. If you want to do something about it, start reseeding and use this experience as a lesson for next year. Water, weed, mow, fertilize, and put up a “keep off the grass” sign.
But if you want to get that crap off of your pool, you should probably start by hosing it down. If you have a permanent above-ground pool, clean what you can and consider replacing the ground beneath it.
Many people with vinyl pools have this problem tenfold. They hose their inflatable pool down, only to have the odor stick around. Some people with vinyl pools have tried methods like:
- Power washing
- Sunlight—leave your vinyl pool outside in the sun for a while and see if the odor goes away.
If none of these methods work, you may need to toss your inflatable pool out.
Will I Get My Lawn Back?
The good news is that after you realize that the grass beneath your pool has died, it’s easy to bring your lawn back. Aerate the soil and do anything else you would normally do when reseeding your lawn. Your lawn should return.
If the grass beneath your pool looks and smells like crap, that’s because it is as close to manure as dead plant matter can get. Grass can be tricky because it does not die immediately; it goes dormant for 2–3 weeks before it starts to decay. Unsuspecting pool owners do not realize that the grass beneath their pool has died, and their yard starts to smell like a sewage plant.
Once you are at that point, remove your pool from the grass. Hose the pool down and take extra steps for odor removal if you have to. Reseed the dead area. Make sure it’s dead, not dormant.
Frequently Asked Questions
Why Does My Dead Grass Smell Like Poop?
The grass beneath a pool smells like poop because it has started composting itself. It will go dormant for 2 to 3 weeks before actually dying, so the smell can sneak up on people. Grass has a high enough nitrogen content that it reeks when it dies.
Is There Anything I Can Do to Prevent Grass from Dying Beneath My Pool?
The blunt answer is, “prepare your lawn ahead of time.” Get rid of the grass where you intend to put your pool before you do anything else. Cement and rocks are both fine ideas beneath larger, sturdier pools. But if you have an inflatable pool, the easiest solution is to move it around your lawn.
What Do I Do with the Dead Patch?
Once you have revealed the dead patch beneath the pool, reseed and treat it as you would any other exposed patch on your lawn. Make sure to reduce foot traffic as your grass regrows.
My Vinyl Pool Stinks! How Do I Fix This?
If you’ve dealt with the dead grass beneath your inflatable pool, you may have another problem: that stench doesn’t want to leave your pool. Hose it down with maximum pressure first. Then, if that did not work, try vinegar and leave your pool to bake in the sun. If none of those work, you may need to dispose of your pool.