Is your lawn having trouble absorbing and draining water? If you start to learn about the basics of soil to fix this problem, you might be led astray. There are two very general kinds of soil that might be beneath your grass: clay and sandy. Sand drains water very well, while clay does not. However, that does not mean that adding sand will help your lawn drainage. Let us explain why that doesn’t work and what you should be doing instead.
Why Sand Doesn’t Help Lawn Drainage
Yes, sandy soils drain water much better than clay soils. Most lawns in Colorado hide a clay-like soil made of red silt that is particularly water-repellant. This makes drainage issues relatively common in the state. You may be tempted to add sand to help. However, adding sand to clay-like soil actually makes conditions worse. The small particles bind up with the clay and form a mixture that is almost like concrete. It will repel even more water and may actually be the death knell that does in your grass.
If you see a golf course or another homeowner adding sand to their lawn, they are doing it because their soil is already sandy (or, we hope that’s why they are doing it!)These soil mixtures may have up to 80% sand particles, with the remaining particles being organic matter and almost no clay. In this situation, the additional sand won’t bind with the clay particles because there simply aren’t enough.
Those who want to invest in their lawn drainage could remove almost all of their current soil and have a sand mix installed. You would also need to change the species of grass that you’re growing. However, there are much less expensive and less extensive ways to improve the drainage on clay soils. We suggest you invest in these methods instead.
How to Improve Lawn Drainage
Clay soil can’t have sand added to it, but it can support organic matter. Essentially, this is broken-down plant material in the form of animal manure or compost. Organic matter will absorb water, and it won’t bind up with the clay particles. Depending on the current conditions of your soil, you may need to add a lot of organic matter, so much that you need to roll back the sod, add the organic material, and then restore the sod.
Homeowners who have well-draining soil can instead sprinkle on a layer of organic matter every year or so to keep the lawn well-supplied. Be sure not to add so much that you smother the grass blades–they still need light.
Other than adding organic matter, there are a few other things you can do to improve your lawn’s drainage:
- Aerate the lawn: Sometimes, thatch build-up can cause drainage problems. Aeration can remove thatch.
- Change the sprinklers: Sometimes, the irrigation system creates lawn drainage problems. It may overwater the whole lawn or overwater a specific section.
A professional landscaper can help you assess your lawn’s drainage and decide how to improve it.