What Causes A Bumpy Lawn?

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Lawn lumps are usually caused by an underlying issue in your yard, so if you want to stop them from reoccurring, it’s essential that you diagnose this issue before doing battle with the bumps.

What Causes A Bumpy Lawn?

Drainage Issues

Even though a bumpy lawn brings along its own drainage problems, sometimes, the bumps themselves are symptomatic of a pre-existing issue in your drainage or irrigation networks.

For instance, if you’ve noticed any bumps or depressions in one particular area, and that area just so happens to be near some water pipes, an outdoor faucet, or a sprinkler system, you need to check for leaks.

Sprinkler systems are the most common cause of lawn erosion as, once they’re installed, people often forget to check them over periodically.


Without a maintenance protocol, the system can easily fall into disrepair, spring a leak, and destabilize your lawn from beneath the surface.

Ground Settling

Ground settling refers to the downward movement of a surface due to the earth below compacting. This is particularly common in new lawns, and it can be exacerbated by the freeze/thaw cycles of the winter months.

The constant changes in state cause the earth to sort of buckle, and rise up into the air.

Ground settling may also be caused by heavy equipment, so if you’ve had any diggers in your yard, the solution may be as simple as moving them elsewhere.

Lawn Disease, Dogs, And Foot Traffic

Anything that kills off a section of your lawn can lead to a bumpy, uneven surface. Whether the perpetrator is a fungus, a dog that likes to relieve itself on the lawn, or even your own feet, the result is the same, bare earth.

Over time, rainfall, wind, and foot traffic will erode these bare spots, eventually forming depressions, ruining the pristine topography of your yard — boo!

fooot traffic

The good news is that if it was a lawn disease that killed off your grass, it’s probably long gone by now, but stay vigilant. If you notice another flare-up elsewhere, you’ll need to identify and treat it as soon as possible.

If animals are the problem, it’s best to keep them off your lawn from here on out, and if foot traffic is the issue, you should consider an alternative path.

Should there be no other way to navigate your yard, why not invest in some stepping stones, so you can get from A to B without disturbing your lawn?

Alternatively, you may need to overseed with a more robust species of grass that can handle the heavy foot traffic, which brings me to my next point.

Soft Grass

They say to leave only footprints when you’re in the wild, but even footprints can be damaging to our own yards. Some species of grass are tougher than others; it’s just the way of things.

Softer grass doesn’t cope well with foot traffic, and once dead, the earth will erode and sink, so tread lightly, or better yet, don’t tread on it at all.

Animals And Insects

Burrowing animals, such as groundhogs, rats, and moles, are another reason your lawn may have taken on a rather rough complexion as of late. Ants pose a problem too, as they will often form large mounds as a base of operations.

Ants aren’t necessarily a threat to the health of your lawn. In fact, they can be a great deterrent for other more vicious pests, but their structures are unsightly and cause just as much a practical dilemma as any other form of lawn bump or depression.

I’d say an animal or insect intruder is probably the most difficult scenario to deal with, as you’ll have to find a way of relocating or repelling the squatter before you can flatten your yard back out again.


Buried Objects

Large pieces of debris hidden by surrounding grass or buried beneath the surface of your lawn will also lead to a bumpy surface, but once the object in question is removed, fixing it will be a total cakewalk.

Tree Roots

The last cause of the dreaded lawn bump is a wayward tree root, and this one is a doozy! Tree roots may take things pretty slowly, but they move with enough force to buckle asphalt, so needless to say, over time, their underground activity can cause bumps to appear in your lawn.

You’ll normally be able to tell if this is the case if your bump is situated near the base of a tree, but as tree roots venture far beyond the canopy diameter, it is possible for root lumps to appear a fair distance from the tree itself.

Unfortunately, besides raising the rest of your lawn to the same level as a bump, you’ll have to take pretty drastic measures to solve this issue (but more on that in just a sec).

tree roots

Why Are Bumpy Lawns Problematic?

Before we dive into some bumpy lawn remedies, let’s take a quick look at why they can be such a nuisance.

Trip Hazards

You’d be forgiven for thinking that it’s perfectly okay to let the odd yard bump slide. It’s not hurting anyone, right? Well, actually, it might do.

If your children have claimed the turf as their private sports field, firstly, my condolences, and secondly, the bumps in your yard pose a trip hazard. It only takes one awkward fall for a little one to end up in hospital with a dislocated thumb, a sprained ankle, or even – god forbid – a broken bone.

In fact, I myself as a child tripped over uneven ground in my family’s front yard, took flight, and landed on my knees with a resonant cracking sound. I seemed fine at first, but the next day I couldn’t walk. 

Adamant that I was faking to get out of a grueling day at school, my mother decided to call my bluff, loaded me in the car, and took me to hospital, where an X-ray confirmed I had a hairline fracture snaking along the top of my right shinbone.

If we level out those pesky bumps, we create a safer environment for kids to play tag, soccer, football, croquet (for the fancier sprogs), or, well…anything really. That means no medical bills — hurray!

bumpy lawn

Plus, the even playing surface will prevent the ball from taking unpredictable turns during the game, inevitably leading to arguments about whether that goal was really a goal, if that touchdown should count, or…whatever the croquet equivalent is (I’ve never played).

But it’s not just kids that stand to injure themselves when coming into contact with the lumpy scourge. Seniors are also at risk. As it can be difficult for people living out the autumn of their years to get back up off the ground after falling over, if no one’s around to help, they may be stuck there for a while.

Sadly, in some cases, the fallen aren’t found in time and pass away. Suddenly those little hills don’t seem so innocent, huh?

Lawn Maintenance

I’m sorry to say, but bumps are bad news for the health of your lawn, folks. The reason being, when you’re cutting your grass, the uneven surface may cause the blades of the mower to scalp the lawn. And the only thing worse than a bumpy lawn is a bumpy lawn with bare spots.

Navigating a smattering of lumps with a lawn mower can also be a pretty physically demanding activity, turning what is usually an enjoyable chore into a drawn-out nightmare.

What’s more, the scalping will take its toll on your lawn mower blades too, as they’re simply not designed to cut through earth. A nice, level lawn, facilitates a quick, healthy cut, allowing us to get on with the rest of our day.

mowing lawn


Of course, you can’t have highs without lows. Each of these irritating lawn pimples is connected by a dipped area. When it rains, and gravity does its thing, all the moisture collects into these low spots and stagnates, significantly increasing the chances of lawn disease.

A level lawn facilitates even drainage, so no one area gets drowned out, keeping your grass lusciously green, thick, and healthy.