Earthworm castings taking over our yard - Ask Extension
Walking on our front and back yards is like walking on hard dirt mounds, and the grass looks terrible, splotchy and sparse. Earthworms are leaving cas...
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Earthworm castings taking over our yard #149511
Asked August 27, 2013, 10:01 AM EDT
Walking on our front and back yards is like walking on hard dirt mounds, and the grass looks terrible, splotchy and sparse. Earthworms are leaving castings consistently this summer. How do we stop them? We have "harvested" them for fishing, but no way can we use that many worms, and it's really a lot of work. Understand it could relate to acidity of soil, but have also read that treatment could kill the grass. I really would appreciate whatever info you might have. Thanks so very much.
Arapahoe County Colorado
Expert Response
Hello,
Earthworms are generally considered to be beneficial rather than a detriment to lawns, but I can understand why you don't like the resulting mounds, which can frequently be unsightly, not to mention the fact that the uneven surface is hard to walk on. With some care you can mitigate some of the effects of having worms in your yard.
First I would suggest that you have your lawn aerated this fall. It is always beneficial for the lawn to aerate in the fall, and this may help your worm problem. Secondly, you can spread a layer of good soil or compost up to about an inch thick and rake it in. This will help to level out the bumps in the lawn. Avoid using a roller to try to even out the surface because it will just serve to compact the soil. Compacted soil is already a problem in the Denver area.
Following is a link to information about earthworms in the yard that you may find helpful:
http://www.ext.colostate.edu/mg/gardennotes/554.html
It's hard to tell without seeing your lawn if the splotchy and sparse conditions are related to the worms or have another cause. However, good cultural practices will probably help this condition and help to make your lawn healthier. This Fact Sheet contains useful information on how to maintain a lawn:
http://www.ext.colostate.edu/pubs/garden/07202.html
Earthworms are generally considered to be beneficial rather than a detriment to lawns, but I can understand why you don't like the resulting mounds, which can frequently be unsightly, not to mention the fact that the uneven surface is hard to walk on. With some care you can mitigate some of the effects of having worms in your yard.
First I would suggest that you have your lawn aerated this fall. It is always beneficial for the lawn to aerate in the fall, and this may help your worm problem. Secondly, you can spread a layer of good soil or compost up to about an inch thick and rake it in. This will help to level out the bumps in the lawn. Avoid using a roller to try to even out the surface because it will just serve to compact the soil. Compacted soil is already a problem in the Denver area.
Following is a link to information about earthworms in the yard that you may find helpful:
http://www.ext.colostate.edu/mg/gardennotes/554.html
It's hard to tell without seeing your lawn if the splotchy and sparse conditions are related to the worms or have another cause. However, good cultural practices will probably help this condition and help to make your lawn healthier. This Fact Sheet contains useful information on how to maintain a lawn:
http://www.ext.colostate.edu/pubs/garden/07202.html
Dear Judy K. Thank you for your response. I have attached a couple of photos of our back yard showing how close the castings are to each other. They are unsightly and compact down
Hello again,
Your lawn does indeed look as though it could use a little work to help it look better.
I would recommend that you do the following:
1. Go to a big box store and purchase a thatch rake if you don't already have one. Then rake well, removing the under layer of dead grass called thatch. This takes a little muscle power.
2. In the next few weeks have your lawn rototilled. You can hire a company to do this or you can rent a rototiller yourself. Just be aware that rototillers are pretty heavy and bulky to handle.
3. Purchase a grass seed blend from a garden center. Talk to the employees there about how much shade you have in your yard so they can select the best seed for your situation. Overseed with the grass seeds immediately after the rototiilling is done. Keep moist. Don't let your yard dry out. This seeding should be done before about the middle of September to avoid frost killing the emerging seedlings.
4. About mid-October fertilize with a lawn fertilizer that is high in nitrogen and iron. Don't use a fertilizer with weed killer at this time.
Next spring I think you will notice a big change in your yard. You should have some healthy new growth. At that time if you are still bothered by the earthworm bumps, you can blend a mixture of soil and peat moss. This can be spread on the lawn and gently raked over the lawn surface. The soil will settle in the depressions and, hopefully, help to level out the surface. The grass with grow up through the deposited soil.
Aeration is something you will want to continue in the years to come. This will help with the worm bumps and give you a healthy lawn. If you can do it twice, spring and fall are the best times. If you choose to do it only once a year, you will want to have it done in the fall. This is the most beneficial time of year for your lawn. Aeration brings oxygen to the roots which are growing extensively this time of year. Strong roots mean a healthy shoot growth.
Good luck. A little work now will help you have a nice lawn next year.
Your lawn does indeed look as though it could use a little work to help it look better.
I would recommend that you do the following:
1. Go to a big box store and purchase a thatch rake if you don't already have one. Then rake well, removing the under layer of dead grass called thatch. This takes a little muscle power.
2. In the next few weeks have your lawn rototilled. You can hire a company to do this or you can rent a rototiller yourself. Just be aware that rototillers are pretty heavy and bulky to handle.
3. Purchase a grass seed blend from a garden center. Talk to the employees there about how much shade you have in your yard so they can select the best seed for your situation. Overseed with the grass seeds immediately after the rototiilling is done. Keep moist. Don't let your yard dry out. This seeding should be done before about the middle of September to avoid frost killing the emerging seedlings.
4. About mid-October fertilize with a lawn fertilizer that is high in nitrogen and iron. Don't use a fertilizer with weed killer at this time.
Next spring I think you will notice a big change in your yard. You should have some healthy new growth. At that time if you are still bothered by the earthworm bumps, you can blend a mixture of soil and peat moss. This can be spread on the lawn and gently raked over the lawn surface. The soil will settle in the depressions and, hopefully, help to level out the surface. The grass with grow up through the deposited soil.
Aeration is something you will want to continue in the years to come. This will help with the worm bumps and give you a healthy lawn. If you can do it twice, spring and fall are the best times. If you choose to do it only once a year, you will want to have it done in the fall. This is the most beneficial time of year for your lawn. Aeration brings oxygen to the roots which are growing extensively this time of year. Strong roots mean a healthy shoot growth.
Good luck. A little work now will help you have a nice lawn next year.
