Lumpy Lawns – Common Causes and How to Fix Them

Why is my lawn so bumpy?

You might be surprised to hear that this is actually a pretty common question, especially in the spring after a cold winter.

Luckily there’s no need to worry; it’s often a natural process and also easy to fix.

I’m going to share the easiest ways to fix a bumpy lawn and how to help prevent it from happening again.

Quick Read

  • Lumps and bumps are natural and will appear on every lawn eventually.
  • They aren’t necessarily a problem unless they make mowing difficult or are a hazard for people walking.
  • How you remedy the bumps depends on the cause.
  • The best way to level a bumpy lawn is to top-dress with fresh soil and grass seed.
  • Avoid using a roller if possible to prevent compaction.

bumpy green zoysia grass lawn

What Causes Bumps to Form on a Lawn?

Before deciding how to tackle your uneven lawn, you first need to establish the cause, or at least rule out a few. Some reasons for bumps can be easily remedied while others are a little trickier.

So, it pays to save some time and effort further down and line by asking yourself first:

What is causing bumps in my lawn?

Bumps in your lawn can appear for many different reasons.

Most of the time, a lawn becomes uneven over time if it has been exposed to too much traffic trauma in wet conditions when the soil is soft.

Bicycles, lawn furniture, football, pets and even the actual act of mowing, can all result in lumps and bumps if the lawn is subjected too often when it is vulnerable.

Other things that can result in a bumpy lawn include:

  • Tree roots growing under the lawn.
  • Freezing and thawing patterns, particularly in soil with clay.
  • Historical land use.
  • Different grass and weed species clumping together.
  • Dead or thin patches of grass that get eroded.
  • Digging creatures like moles or voles.

Do Bumps in Your Lawn Matter?

If you’re reading this article, then chances are you care about the lumps in your lawn. And if you care, then they matter.

But what if you don’t care? Should you still fix them?

The main things to think about are whether the bumps are a trip hazard, and whether any lower areas develop pooling water in wet weather.

If you have vulnerable people living on the property then making sure the lawn is even is important to prevent accidents. It’s also worth avoiding water pooling during wet weather as this can compromise grass health.

However, in saying all that, there’s nothing overtly wrong with having a lumpy lawn. After all, lumps and bumps are a part of nature. Provided you don’t cut your lawn short enough to scalp the higher areas, then it’s not the end of the world to leave some humps in your lawn.

person using zero-turn lawnmower

How to Fix a Bumpy Lawn

If you’ve made it this far, chances are you’re still wondering how to fix a lumpy lawn. So, let’s get into it.


The best way to fix a bumpy lawn that has occurred over time as a result of freezing and thawing is to top-dress it with fresh soil or compost.

What this means is spreading a layer of soil or compost over the whole of your yard and raking it out so that it fills in the holes and depressions. In these areas, where the soil ends up being a bit deeper, you can then reseed with fresh grass seed.

Just be sure to use the right kind of grass seed for your region and climate. I have an article dedicated to the different types of grass seed available and the conditions they’re best suited to if you’re not sure.

Replace Patches of Turf

Similar to top dressing and reseeding, another option is to remove the turf in places where there are obvious depressions, and fill in the depression with fresh soil.

Once the fresh soil is in place and leveled to match the surrounding lawn height, replace the turf with either the same piece of sod if it is healthy, or a new piece.


If your lawn is a complete disaster and the options above won’t cut it, then you always have the option of starting again. This would entail digging up the turf, leveling the ground, and either relaying new ready-to-go turf, or adding fresh soil and grass seed.

I have another guide to leveling your yard that might be helpful if you’re going to take this route.

Spot Fix

Lastly, if your lawn is suffering from bumps as a result of localized issues like tree roots, clumping grass species, or digging animals, then you only need to target that specific spot and the cause.

Tree roots shouldn’t be damaged so unless you can top dress the surrounding area to raise the level of the lawn, you may just have to make peace with them.

Clumping species of grass should be dug up and replaced with fresh sod with the grass species of your choice. It will take a bit of time for the lawn to look uniform again but it will get there eventually. Just be sure to water the new turf well while it gets established.

Lastly, if the mounds in your yard are caused by moles or voles then simply pushing them down with your foot when the soil is soft will suffice. If your lawn is healthy then the surrounding grass should spread over the bare patch quickly.

gardener pulling a lawn roller

Should I Roll My Bumpy Lawn?

You might be wondering why I haven’t recommended simply rolling your lawn with a heavy lawn roller.

The truth is, there may be instances where it is appropriate to use a lawn roller. For example, if you know that the bumps in your lawn have been caused by an animal, like a mole or your pet having a dig, and your lawn doesn’t get easily compacted, then a quick roll might be appropriate.

However, often, a lawn roller might do more harm than good and leave you with a compacted lawn.

If you have decided that rolling is what your lawn needs, I have a guide to the best lawn rollers to help you out. Just be sure to aerate afterwards!

If you’re new to lawn care and not yet set up with the appropriate tools, have a read of my guide to lawn care tools here.

How to Prevent Your Lawn from Developing More Bumps in the Future

Since soil is full of living things, and living things naturally move and change form over time, maintaining a perfectly flat lawn is an unrealistic expectation.

However, there are things that you can do to reduce the chances of your lawn developing another serious bump problem.

These are:

man working with a yellow zeru turn lawn mower

Check for Insects and Diseases

Some pests and diseases can result in a lumpy lawn if they cause the grass to die in patches. These dead patches can then turn into depressions as the thatch and underlying soil is eroded away by wind and rain.

Keeping your lawn dense, healthy and disease-free will help to prevent bumps from forming.

Check for Clumping Grass and Weed Species

Some grass species, like clumping tall fescue, grow in clumps in a way that makes your lawn appear bumpy. The soil underneath is most likely flat, but as the clumps form and develop a thicker layer of thatch than the surrounding species, they can appear to be sitting higher on the lawn.

Some species of grass grow a darker green, or grow quicker than the surrounding grass, also creating the illusion of bumps.

The best way to manage this is to keep your lawn thick and lush with no space for opportunist invaders to set up shop. Overseeding at the start of the growing season is a good way to do this.

You can also manually dig up any clumps that have already established themselves and reseed those patches.

Check for Burrowing Animals like Moles

Moles and voles are notorious for creating lumpy lawns. Your options are to either manually flatten the hills as they appear, or find a humane way to discourage the animals from your property.

Aerate as Required

Aerating your lawn can help to prevent the appearance of bumps and depressions by promoting overall lawn health and helping to support drainage.

Aerating is just one lawn care task that should happen on a yearly basis for most lawns. Other lawn care tasks that can help to prevent a bumpy lawn, simply by keeping your lawn healthy and thick, are laid out in this calendar.

Use Correct Mowing Practices

Did you know that mowing your lawn in the same direction and pattern every time can create an uneven lawn? Repeatedly running the mower over the same patch of lawn will result in troughs and depressions where the wheels go.

Mix it up a bit and your lawn will thank you.

Check this article for more lawn mowing tips.

Avoid Using the Lawn when the Ground is Wet

Last but not least, one of the most important ways to look after your lawn is to avoid subjecting it to trauma while it is wet and vulnerable.

When the soil is wet, it is much more easily compacted and torn up. Wait until it’s dry before letting the pets and kids loose!


It appears that there are actually multiple causes for bumpy lawns, and just as many solutions.

Some of the causes are hard to avoid, like the natural settling of the ground during freezing and thawing cycles. Others, like using the lawn when it’s wet, are easier.

The solution you choose will depend on the cause of the bumps, but, most of the time, top dressing with fresh soil and seed is the best option for a healthy lawn.

I hope you’ve found this article helpful and are no longer wondering, why is my lawn so bumpy?

Let me know if you have any thoughts on what I’ve written here, I’d love to hear them!

Andy Gibson

My name's Gibson. Andy Gibson. I like to think of myself as the Bond of the backyard, that is if yard work ever became sexy. I write about everything about indoor and outdoor gardening and the dread-it-but-still-need-to-do-it chores around the yard, like cleaning out the gutter guards.

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