Compacted soil is a common problem for lawn care enthusiasts. It can cause major problems with your grass growth as it doesn’t allow water or air to circulate properly, which can lead to problems with drainage and moisture retention. Fortunately, there are several ways to soften compacted lawn soil.
What is compacted soil
When the soil under your lawn is healthy, it contains tiny spaces between the soil particles that allow air and water to reach the deepest part of the plants roots – which in turn leads to a soft and healthy lawn.
Compacted soil occurs when the soil is packed down so tightly that these spaces between the soil particles no longer exist and grass roots can no longer penetrate it, it also prevents air and moisture from penetrating the ground and eventually can lead to lawn death.
Some of the causes of hard lawn soil are:
- Heavy foot or vehicle traffic
- Outdoor activities
- Heavy rain
- Over time, the soil can settle and become compacted
Why hard soil is bad for your lawn
Compacted soil affects lawns in a variety of ways. Compact soil is often too tight for roots to penetrate, and your lawn depends on its roots for water and mineral nutrients. When roots can no longer reach the lower levels of soil, your lawn will stop growing, and new blades of grass will stop replacing older, dead blades. Over time, your lawn will start to look thin and unhealthy.
Worse yet, compacted soil can even be too tightly packed for water to penetrate. When this happens, even healthy blades of grass will no longer get the water they need, since the water won’t be getting past the surface. This can lead to your lawn turning yellow and grass dying off.
Hard soil can also cause an Anaerobic environment in the soil, which means that there is essentially a lack of oxygen in the soil.
If your grass is dying and you can’t figure out why go outside and try to stick a spade in the ground. If you can’t, the soil is almost certainly too compact for water to penetrate efficiently.
Finally, hard soil can affect more than your lawn. If water can no longer penetrate the hard soil, it will flow across the surface to the most convenient spot. If that spot is a basement window or a crack in a foundation wall, you can quickly end up with a flooded basement.
How to Soften compacted soil
There are several ways to soften compacted lawn soil. Depending on your situation and budget, one of these methods should soften your previously hard soil and allow your lawn to recover.
Core Aeration or Lawn Coring
Core aeration is one of the most effective ways to soften hard soil. It usually involves using a special machine called a core aerator and physically removing plugs of soil from your lawn, which reduces compaction and allows air, water, and nutrients to penetrate deeper into the soil.
These core aeration machines are typically expensive to buy but can be hired for a much more cost-effective rate from a store such as home depot.
There are also manual lawn corers available (such as this model), these are much slower as they remove only 2 or 3 cores at a time. Using these manual corers takes a bit of strength as you need to manually push the corer into the hard ground, then pull it back out to remove the plugs.
Spike or Slit aeration devices are simpler than their coring counterparts. Spike devices simply have a series of long spikes that are pushed into the ground to make holes.
These spikes can be on the bottom of special shoes, or on a tool that you push into the ground with your hands.
Spike/slit aeration is much less effective than lawn coring, as it simply pushes the hard soil out of its way to make a hole, instead of actually removing a section and can actually cause additional compaction of the soil.
Lawn tillage is the process of using a special machine or garden tiller to break up and turn over the topsoil on your lawn. This usually results in needing to reseed the area.
Tillers are much more powerful than core aerators and can penetrate deeper into the soil, allowing you to reach the deepest part of the plant’s roots – which in turn leads to a healthier, more vibrant lawn.
Tilling should only be considered as a good option if you want to start your lawn from scratch.
Liquid Lawn Aeration
Liquid Lawn Aeration is the application of a liquid aeration solution to lawns and turf areas via a garden sprayer or hose-end sprayer. This liquid solution is applied directly onto the soil surface, where it quickly penetrates down into the root zone and breaks apart compacted soil particles.
Liquid lawn aerators are easier to apply, but take longer to yield results, but ultimately they do work and perform as advertised.
Does Gypsum help with compacted soil?
There are some resources that recommend adding gypsum to your lawn to help with compacted soil. The fact is that in most cases, it will not help at all.
You can read more details about it here, but the summarized version is that gypsum does not work well on layered soils, which is exactly what most American homes have.
Adjust your Lawn Care Schedule To Prevent hard soil
As with many home improvement issues, an ounce of soil compaction prevention is worth a pound of expensive roto-tilling cure. Aerating your lawn regularly should be part of your lawn maintenance plan and will keep the top layer of soil loose, so your grass will get plenty of water.
Aerate and Topdress Regularly
Aeration of your lawn isn’t just something you should do when you have a hard soil problem. It should also be part of your regular lawn maintenance plan.
After you carry out the aeration, you can topdress your lawn to help further benefit the grass. Top dressing involves adding a light layer of compost, sand, or a mix of the two over the top of the lawn. Top dressing assists with drainage and introduces beneficial microbes.
We recommend aerating in late summer using a core aerator.
Keeping your lawn regularly watered is also a good way to soften soil. Use a sprinkler and water the grass enough so that it becomes saturated, but not muddy.
You can learn more about how much to water your grass in our lawn care guide.
Dethatching is an important part of lawn maintenance and care. It involves the removal of dead grass clippings, matted thatch, and other debris from the soil surface to maintain a healthy lawn.
This is done using a special dethatching device.
By removing this build-up, it helps promote better air circulation and drainage, increases sunlight exposure to the grass’ roots, reduces soil compaction, and encourages beneficial microorganisms in the soil.
Dethatching also improves grass growth and turf health, helps reduce weed infestation, and reduces disease risk. Dethatching is best completed in spring.
Cutting your grass higher leaves a nice layer of lawn above your soil which in turn protects your soil from being compressed by foot traffic or other activities that take place on your lawn.