Mystery brown spots in the lawn have been frustrating homeowners for ages. Just when you think you’ve got it all figured out, and your lawn looks lush and green edge-to-edge, a patch of grass starts dying and you’ve got no idea why.
There are a number of reasons this can happen, with everything from pets to humans to chemicals and diseases to blame. To find out exactly what’s causing your brown spots, you’ll need to do a bit of research. Once you’ve identified what is causing the problem, you’ll know how to handle it and tell those brown spots goodbye.
Here’s a list of the most common reasons for dying grass and mystery brown spots on the lawn, along with ideas for helping your grass get healthy again.
Chemicals such as gasoline, herbicides and pesticides can kill grass if spilled or over-used on the lawn. Even insect repellents can burn your lawn when sprayed on the grass blades. If you’ve had a spill, remove grass, soak the area with water daily for a week to dilute any chemicals left, then sow grass seeds or put down sod. If you’ve been using herbicides or pesticides in the area, double check the directions and cut back a little to see if it makes a difference.
A little fertilizer is good – too much, though, can be a bad thing. Fertilizers are essentially salts with added nutrients. Using too much can damage the roots, causing grass to wither and die. If you’re planting new grass or sod, let it get established before applying fertilizer. Use a spreader to ensure even application and avoid the risk of it clumping and causing fertilizer burns.
Animal urine is one of most common culprits for yellow or brown spots on the lawn. If you have a dog, notice where they go and see if it matches up with your brown spots. If they are the cause, try to train them to go in areas out of sight or not on the grass. No dog? There are still plenty of other animals that can be using your lawn for a latrine, especially at night when no one is looking including cats, raccoons, rabbits, possums and other roaming animals. (Including neighbors who let their dog run off the leash). Wild animals can be discouraged with simple things like motion-detector lights or sprinkler heads. As for inconsiderate neighbors, well, good luck!
Dull mower blades are something that can harm grass, causing brown spots all over your lawn. Dull blades tear grass, instead of cleaning cutting it, causing damage that eventually kills grass. If you notice random spots all over your lawn, and grass looks ragged instead of cleanly cut, check your blades or ask your gardener to check theirs. Lawn mowers should be serviced at least once per year. More if used by a service that handles multiple homes.
Hard-packed (compacted) soil: Here in the Visalia area, compacted soil is one of the most common problems for growing healthy grass or other plants. Here’s an easy way to see if your soil is hostile to growing conditions: Take a screwdriver and try to push it into the soil. If it doesn’t go easily, your soil is likely compacted. Try aerating and adding amendment or organic matter into your soil to improve.
Grubs and other insects can also be a cause for brown spots and dying grass. If you’re able to pull your soil back and look under one of the brown spots, check for fat, while, curved worms. If you find them, check at your local home and garden store for grub control products. We mentioned raccoons earlier. If they’ve been visiting you often, and leaving what looks like divots in your yard, check there, too. They are often attracted by grubs, which they love to eat, and a good warning sign that you’re infested.
Finally, there just might be a fungus lurking in your lawn. Overwatering or areas that don’t drain well can provide space for fungus to thrive in. Fungus often shows up as circular or irregular brown spots, and can sometimes be seen as a white, powdery substance on roots when they are pulled up. Give lawns a dose of fungicide, and read directions for how much water to use. You’ll definitely need to cut back as fungus requires a lot of moisture to survive.
If none of these circumstances sound like something that could be harming your grass, your best bet is to take a sample of the affected area, including soil, dead grass, roots and all, to a landscaping and irrigation expert or your local cooperative and they’ll help you get to the root of the matter best of all.