Lumpy-Bumpy Lawn – Causes and Fixes (How to Repair a Bumpy Lawn)

One call we get a lot of in the Spring is “My lawn is really bumpy and uneven. Can you repair my lumpy lawn, could you roll my lawn for me?” On the heavy clay soil we have in the GTA, nothing short of a steamroller can exert enough pressure to flatten a lawn by force. And if you did manage it, the soil would be so compact it would choke your grass to death anyway.

Lumps, bumps, holes, and dips will show up on every lawn sooner or later. They happen for many different reasons throughout the year. Finding the right long-term-fix depends on the cause of the bump. So how can you fix a bumpy lawn?

Causes for A Lumpy Bumpy Lawn

There are a number of reasons why you might be dealing with a lumpy, bumpy yard that is in need of repair.

  • In Spring, bumps often appear as the frozen, dense clay soil thaws unevenly. It heaves and buckles like a bunched-up carpet.
  • Animals, like voles and pets, sometimes dig holes in lawns, causing a bump of soil or heaved turf to appear.
  • Children at play can also dig holes causing your lawn to become lumpy, or excessive activity when the lawn is too soft from rain or snow
  • Depressions can be created if people or animals walk on lawns that are too soft (like in the early spring or after long rains).
  • Some heavy gardening equipment can leave holes or ruts as well if misused.
  • Thicker-matted weed grasses like clump tall fescue create higher surfaces in the lawn
  • Tree roots that crest the soil surface as they grow in search of water or due to frost heaving are a big culprit (even from trees in the yard next door)

Sometimes fixing a bumpy lawn is as simple as just filling the disturbed soil back in and topping up with a good topsoil (hopefully weed-free). If they’re small, the existing grass will grow over the hole. Larger spots should be seeded or even patched with sod.

If part of the lawn sinks and creates a depression, the first thing to do is determine why. Removing the cause before correcting the effect is crucial. For any depression an inch or deeper, repair should involve removing the sod, correcting the cause of the sinking, and then backfilling with new soil with enough extra to allow for settling. The removed sod can be put back in place if it is still in good shape, or replaced with new sod or seed. A shallow depression in a lumpy, bumpy lawn – less than an inch deep – can be corrected gradually by top dressing over it. Topsoil and sand mixes are best for this.

A very common problem is that people often perceive a lawn is bumpy when it has nothing to do with soil!  The lawn is made up of many layers, for simplicity, let’s say: the soil, roots, thatch, and the blades.  Thatch is the area, just above the soil, that protects the roots.  It is normally about 1/4″-1″ in height of matted decomposing grass clippings and generally dying old grass plants that fade away as new plants are generated.  When you have a thin lawn or a disease or insect problem that is weakening an area (think Chinch bugs), the blades go first, then the thatch rapidly decomposes leaving bare soil. This bare area then erodes even deeper with rainfall, wind, and activity. That leaves a depression when compared to the surrounding area of a healthy lawn.  This is what we describe as the illusion of a bump.  Multiply that by several areas and voilà! You feel like you have a bumpy lawn, especially when mowing!

Bumps and rises also need to be diagnosed before correction. If caused by an object, it will need to be removed. If a bump is from burrowing animals, they will have to be removed before the area can be smoothed. It may be possible to flatten smaller bumps by stepping on them when wet.

how to fix a lumpy bumpy lawn near Ontario

The Best Way to Repair A Lumpy Lawn That Has A Few Bumps

It is actually quite simple to fix lumpy grass issues and prevent them from reoccurring if you have a green thick and healthy lawn. A comprehensive lawn care program will help do this for you, make sure that it includes:

  • high-end nutrition components that thicken and fortify your grass plants,
  • regular aeration to loosen the soil and lessen heaving,
  • overseeeding to thicken the lawn and create a stronger more pest-resistant lawns,
  • and proactive insect control for Grubs and Chinch bugs.

Spring is the best AND worst time for people worried about how to fix a lumpy lawn. The ground is soft and the grass grows quickly to cover any repairs, but snowmelt-saturated soil plus traffic on your lawn add up to new bumps.  You can read more in our April lawn care experts checklist. There are tips to avoiding creating ruts from lawn mower wheels when you mow the lawn in our lawn cutting tips section as well.

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FAQ About Best Lawn Care Practices

🌱When is the Best Time to Water My Lawn?

Take it from the lawn experts at LawnSavers, the best time to water your lawn is in the early morning. The 2nd best time is RIGHT NOW! Watering in the morning is best because this allows the water to soak deep into the soil (without evaporation) and allows the leaves of the grass plant to dry before the water evaporates as it gets warmer in the day.  If you can’t water in the morning, evenings are OK, just try to do it earlier!  (better to water any time, than not water at all – water deeply when you water).

🌱How Many Times a Week Should I Water My Lawn?

You need to water at least once a week for at least an hour in each area, this generally provides 1-1.5″ of water to the roots (a tuna cans height) (exceptions: 1. when you seed &  2. if you have an automated system 3. When we are experiencing extreme heat).
New Seeding Watering: Seed must be kept moist until established.  This will be influenced by the amount of sun, wind and heat you are experiencing in your particular area.  It is normal to require 3-4 short watering’s per day to maintain a moist seedbed.  Use a light stream of water to lessen disturbance of the seedbed.

🌱What is the Proper Height to Mow Grass To Keep It Healthy?

In the spring (May-June) and fall (September-November), your lawn should be kept at the 2.5 – 3-inch mark and in the hotter and drier summer periods at least 3 inches.  Contrary to popular belief, if you cut the lawn shorter it doesn’t make it grow at a slower rate, it can actually cause it to lose moisture and scorch, as well as promoting weed and crabgrass growth.

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Check out what Maria says about LawnSavers on HomeStars:

“LawnSavers first rescued my lawn 4 years ago . They now help me to maintain its good appearance and health by a number of services including lawn and hard service weeding, aeration, grub control, fertilizer application , and seeding. They are always prompt, knowledgeable and available!”

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