Best Topsoil Blend For a Lumpy Lawn

Thank you for writing. Before you can figure out how to treat a bumpy lumpy lawn, you have to figure our why it is lumpy. It is kind of like the problem of paint blisters on walls--if the wall is wet...
The main causes are
Moles/voles and other rodents
https://extension.purdue.edu/news/county/whitley/2024/04/moles-and-voles-whats-the-difference.html
https://extension.umn.edu/planting-and-growing-guides/vole-damage

Worms
https://extension.umn.edu/yard-and-garden-insects/sod-webworms
https://ipm.cahnr.uconn.edu/jumping_worms/

Grubs https://extension.umn.edu/yard-and-garden-insects/japanese-beetles

I can not help you much without a photo. I suggest that you dig up a shallow shovel of dirt in an area of damaged lawn and look for worms and grubs.
This is another way to find grubs.

&t=43s
The best way to find grubs.
https://www.canr.msu.edu/news/how_to_choose_and_when_to_apply_grub_control_products_for_your_lawn

Steve Miles, Master Gardener, Hennepin County MN (I am a human being, not a bot nor AI). I am an avid gardener but am not a degreed or certified horticulturist or arborist. I am happy to receive follow-up questions if my responses are incomplete or unclear. This is the University of MN' garden soil testing service. https://soiltest.cfans.umn.edu/testing-services/lawn-garden This is guidance on how to find a tree expert. https://extension.umn.edu/planting-and-growing-guides/how-hire-tree-care-professional The Minnesota Landscape Arboretum is a wonderful place to see and learn about plants that grow in Minnesota. https://mngardens.horticulture.umn.edu/minnesota-landscape-arboretum Replied April 25, 2026, 12:08 PM EDT

Thanks for getting back to me, Steve.

Every now and again a mole will show up. I'll trap it and then we're good for a few years. I assume there are some grubs, but never really searched them out.

There are definitely Japanese beetles out there. I had a raspberry patch they loved to gnaw on. Back then I had a scent trap that would fill up 2-3 times a summer. Still see them on other plants - but nowhere near what it was with the raspberries.

Plenty of worms and night crawlers too.

See attached pics of the front and back yards. Let mew know if you can't open them.

Back1.jpeg

Back2.jpeg

Back3.jpeg

Thank you,
Greg Solberg
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On Sat, Apr 25, 2026 at 11:08 AM Ask Extension <<personal data hidden>> wrote:

The Question Asker Replied April 25, 2026, 1:40 PM EDT

Thank you for writing back.
I hate to tell you this but Japanese beetle traps make the problem much worse. They have a sex hormone that draws beetles from about a mile and a half away. Sure some get trapped, the rest feed and breed. https://extension.umn.edu/yard-and-garden-insects/japanese-beetles#non-chemical-management-options-1591111
This plausibly looks like grubs. Peel off a sq foot of grass, two inches deep and see that is down there.

Don’t use Japanese beetle traps. Hanging a trap in a home garden is not an effective way to protect plants. And they may attract more insects to your yard.

The traps attract beetles using synthetic female sex pheromones and a blend of chemicals with a strong floral odor. They were developed to monitor for the presence of Japanese beetles so that management strategies could be implemented.

Always let your lawn grow as high as possible and then mow the top third. The reason is that the taller the grass, the deeper the roots, the stronger the grass and the more resistant to weed invasion.

https://extension.umn.edu/lawn-care/mowing-practices-healthy-lawns

Steve Miles, Master Gardener, Hennepin County MN (I am a human being, not a bot nor AI). I am an avid gardener but am not a degreed or certified horticulturist or arborist. I am happy to receive follow-up questions if my responses are incomplete or unclear. This is the University of MN' garden soil testing service. https://soiltest.cfans.umn.edu/testing-services/lawn-garden This is guidance on how to find a tree expert. https://extension.umn.edu/planting-and-growing-guides/how-hire-tree-care-professional The Minnesota Landscape Arboretum is a wonderful place to see and learn about plants that grow in Minnesota. https://mngardens.horticulture.umn.edu/minnesota-landscape-arboretum Replied April 25, 2026, 2:46 PM EDT

Thanks!

I haven’t used a beetle trap in 10 years.

What I want to know is what would be the best topsoil / topsoil blend so I can, over time - smooth out the lawn.

Any thoughts?

Thank you,
Greg Solberg

On Sat, Apr 25, 2026 at 1:46 PM Ask Extension <<personal data hidden>> wrote:

The Question Asker Replied April 25, 2026, 6:00 PM EDT

I hope this helps.
https://www.milorganite.com/blog/Lawn/how-improve-lumpy-lawn

https://turf.purdue.edu/bumpy-lawn/#:~:text=Most%20lawns%20are%20bumpy%20because,down%20to%20the%20soil%20surface.
https://yardandgarden.extension.iastate.edu/how-to/bumpy-rough-lawns

Steve Miles, Master Gardener, Hennepin County MN (I am a human being, not a bot nor AI). I am an avid gardener but am not a degreed or certified horticulturist or arborist. I am happy to receive follow-up questions if my responses are incomplete or unclear. This is the University of MN' garden soil testing service. https://soiltest.cfans.umn.edu/testing-services/lawn-garden This is guidance on how to find a tree expert. https://extension.umn.edu/planting-and-growing-guides/how-hire-tree-care-professional The Minnesota Landscape Arboretum is a wonderful place to see and learn about plants that grow in Minnesota. https://mngardens.horticulture.umn.edu/minnesota-landscape-arboretum Replied April 26, 2026, 8:53 AM EDT

Thanks for your help - much appreciated!

Take care,

Greg

On Sun, Apr 26, 2026 at 7:53 AM Ask Extension <<personal data hidden>> wrote:

The Question Asker Replied April 26, 2026, 12:30 PM EDT

Best Topsoil Blend For a Lumpy Lawn #929494

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