A bumpy lawn is unsafe, unsightly, and hard to maintain. Further, the depressions can cause drainage problems in your yard. You must establish why your lawn is uneven to provide a lasting solution.
Why is my lawn uneven?
The following are reasons why a lawn is bumpy or sunken:
1. Poor ground settling
Depressions, and bumps, may appear on the lawn after heavy rains and freezing and thawing cycles. This is likely to happen when the ground is not properly graded or compacted before starting a new lawn.
2. Heavy traffic
Moving heavy equipment across a wet lawn can leave its surface uneven. Driving on the lawn and mowing when the ground is wet and common culprits for this problem.
3. Animal activities
Both domestic and wild animals can dig up your lawn in search of grubs and other soil-underlying insects, for shelter or for fun. Animals like dogs, groundhogs, or moles can dig holes in your lawn overnight and create hips of soil that may damage the grass.
Pests and diseases
Pests and diseases cause thinning of grass in some spots of the lawn. Within no time, this will result in bare patches. Water, winds, and rain will erode the soil in such areas, and over time, you will end up with dents and depressions in your lawn.
It is common to find large roots of trees in the soil, especially when preparing the ground for a lawn. If you do not remove the roots, a time will come when they will start to decompose, and as a result, the soil will sink to occupy the void space.
Thatch is a collection of plant materials, dead and alive, lying at the base of grass plants, where stems meet roots and soil. Excess thatch greater than 3/4 inch prevents air, water, and nutrients from reaching the grassroots and makes a lawn bumpy and spongy.
How to Level a Bumpy Lawn
To level your lawn, you’ll need to use the right lawn leveling equipment and do it when the grass is actively growing. Spring is always the ideal time to carry out lawn repairs, as the weather conditions favor grass recovery and growth.
Depending on the nature of the bumps on your lawn, you’ll need one or more of the following lawn leveling equipment.
- A lawn leveling rake
- A lawn roller
- A landscape rake
- A shovel or hoe
- A wheelbarrow
- A grader tractor
Effective lawn leveling methods and steps
Before you get started, assess the nature of the bumps and unevenness in your lawn. For small bumps and a few dents, choose a less intensive approach like topdressing or use a lawn roller to flatten them. A severe case will need a more aggressive approach, such as removing the sod and re-grading the area.
Using a lawn roller
Using a lawn roller effectively works in fixing uneven lawns with moderate bumps or shallow depressions. For a few countable bumps, try to step on them when the ground is soft. If this doesn’t help, get a lawn roller, fill it with water to a third full, and go back and forth over them.
If the bumps are persistent, add more water to the roller and repeat the process. Be careful not to overdo it, as rolling can easily compact your lawn soil, making it difficult for air, water, and nutrients to reach the grass root.
Topdressing a lawn
Topdressing works in leveling numerous but mild depressions in the lawn. It simply involves adding and spreading more organic material to the lawn. A mix of soil with a well-decomposed compost or sand is great for this. Compost is preferred as it adds more nutrients to the soil.
You’ll need a wheelbarrow to transport the material to the site, a lawn leveling rake, or a push broom to spread and work the material in the grass. Here are the steps:
- Start by mowing your lawn at the lowest setting possible
- Use a garden rake or a de-thatcher to get rid of any thatch in the lawn
- In a wheelbarrow, mix well-decomposed compost with soil
- Apply scoops of the soil mix to low areas of the lawn using a shovel
- Using a gardening rake, spread the material evenly in low areas to a tune of 1/4 to 1/2 inch. Applying more than that can be smoother and kill your grass.
- With a leveling rake or push broom, thoroughly work the compost mixture into the grass
- Water the grass to stabilize the topdressing material into the ground further.
- Keep monitoring the progress in the lawn and repeat, if necessary, every time the grass recovers until your lawn becomes flat and fully even.
Filling holes with soil
Holes created by animals can be filled with new topsoil to create a flat area. Once done, you’ll need to over-seed the area. The approach can also be used in dealing with deep dents in lawns that are covered with grass.
- Remove the sod over the low spot using a sod cutter or a hoe. Safely keep the sod if you plan to reuse it or discard it if you install a new one.
- Shovel a generous amount of topsoil into the hole or where you have removed the sod until the area becomes even with the rest.
- While adding topsoil, also keep adding water to help the soil settle properly
- Now reinstall your sod or use a new one, depending on your preference.
- Thoroughly water the new sod until the grass gets established
Re-grading your yard
Topdressing or filling with topsoil is not likely to solve the problem when your lawn has severe bumps and sunken depressions. You may need to re-grade the area and establish a new lawn. Depending on the size of your yard, you may have to use more advanced equipment, like a grader tractor.
When grading, you should always aim to slope the ground away from your house or patio. This is to prevent cases of standing water in the yard when it rains. The maximum slope in a lawn should be no more than twelve inches for every four feet. Here is how to achieve it:
- Drive stakes in the ground and use a transit level to establish a slope line for the yard. The equipment can be hired from a nearby landscaping store, or you can hire a professional service.
- Next, remove the topsoil from the target area. You may use simple tools like a hoe, shovel, and wheelbarrow or hire grading services when dealing with a large yard.
- Once done, spread two inches of topsoil into the first two inches of subsoil. This will blend the two layers of soil, which helps solve drainage issues in the soil.
- Finally, spread about 4 inches of the rest of the topsoil on the area as you aim for the last grade to match your outdoor fixtures like patios, driveways, walkways, or the adjacent existing lawn.
- Once everything is set, you can start a new lawn from seed or sod installation. Then keep watering the new lawn until your grass gets established.
A lawn without bumps and depressions provides a safe place to walk on, for kids to play, and for sporting activities. Lawn maintenance also becomes enjoyable when dealing with flat even surfaces. However, it is not a surprise for your lawn to become bumpy. If this happens, I hope you know why and what to do.