Can You Add Topsoil Over an Existing Lawn Without Removing the Grass? Expert Advice

Adding topsoil to your existing lawn can significantly enhance its quality and appearance with the right approach. Over my 22 years in landscaping, I've seen firsthand the benefits and challenges of this technique. Here's a comprehensive guide to help you understand whether adding topsoil over an existing lawn is right for your project, and if so, how to do it correctly.

When Can You Add Topsoil?

The best times to add topsoil to your lawn are early spring or fall. Avoid applying topsoil during the peak of summer or the dead of winter. These extreme seasons can stress your grass, making it more susceptible to damage from the added weight of new soil.

Picking the Right Topsoil

Quality is key when it comes to topsoil. Opt for rich, dark, and crumbly soil that can support healthy root growth. Avoid using sandy or clay-heavy topsoil as these types may not mix well with your existing lawn or drain poorly, leading to compacted soil and other issues.

Preparing Your Lawn for Topsoil

To prepare your lawn, start by mowing it to about 1.5 inches high. Next, remove any debris or dead grass with a rake. This step, often underestimated, is crucial for ensuring the topsoil settles properly and doesn't suffocate the remaining grass.

Spreading the Soil

Spread a thin layer of topsoil over the lawn, about a quarter to a half-inch thick. Use the back of a rake to level the soil out evenly, making sure the tips of the grass are still visible. This approach ensures good drainage and allows the grass to continue photosynthesizing.

Water It In: Give the newly applied topsoil a thorough watering to help it settle and start integrating with your existing lawn. Proper hydration is essential for the topsoil to become part of the ecosystem rather than sitting atop your grass.

Optional: Overseeding for Enhanced Growth

If your lawn has thin spots or weak areas, consider overseeding the topsoil. This will help fill in those gaps and strengthen the overall health and density of your lawn. Overseeding can be a beneficial addition if you’re looking for improved grass coverage.

Chemical Considerations

It's important to note that certain chemicals, like glyphosate and fluazifop, can be detrimental to bermuda grass if used excessively. These chemicals can mix into a soil blend that is difficult to control. In such cases, you would need to apply a mixture containing 12.8 ounces of 41% glyphosate per gallon and two-thirds of an ounce of commercial-grade Fusilade II per gallon. These applications should be made every 5-7 days, adhering strictly to the label instructions.

Using a Tiller and Fertilizer

After applying the soil and allowing it to settle, use a small tiller, such as a Mantis, to loosen the soil. This step is crucial for aerating the ground and making it ready for planting or ground cover. Additionally, rake in a 6-6-6 fertilizer at a rate of about 5 pounds per hundred square feet, which will further enhance the soil's fertility and promote healthy growth.

Conclusion: While it is possible to add topsoil to an existing lawn without removing the grass, careful consideration of the timing, quality of soil, and preparation of the lawn is essential. Ensuring the right conditions will help your lawn thrive and look its best.