| Key Takeaways |
|---|
| • Topdressing spreads a thin layer of compost, sand, or topsoil over your lawn to improve the soil, reduce thatch, and smooth uneven ground. • Match the material to your existing soil, and time the job to your grass type: fall for cool-season grasses and spring for warm-season grasses. • Topdressing is labor-intensive but doable as a DIY project, and it works best when paired with core aeration and overseeding. |
Upon first thought, it seems almost absurd to spread a layer of compost or sand over your grass. After all, dirt is supposed to be under the grass.
But that is exactly what topdressing a lawn is. Knowing the benefits and how to do it is the first step in this organic lawn care strategy, and this guide covers the materials, timing, and steps you need.
If you would rather leave the heavy lifting to a pro, LawnStarter’s landscaping pros can help you.
What Is Topdressing a Lawn?
Topdressing a lawn is accomplished by spreading a thin layer of material, such as compost or sand, over the grass. This practice dates back to when golf was first invented in Scotland and is gaining popularity with homeowners transitioning to organic lawn care.
Benefits of Topdressing a Lawn
But why is it good to add soil to the lawn in the first place? According to Ginny Rosenkranz, principal agent associate at the University of Maryland Extension, topdressing “promotes a quicker turfgrass recovery from aerating and dethatching, helps to control thatch through enhanced microbial activity, and reduces some diseases.”
When the soil under your grass starts to lose its oomph, or it’s a new lawn that isn’t doing well, pulling all of the grass up to amend it isn’t a feasible option. Topdressing is a simpler, albeit still challenging, way to see the following benefits in your lawn:
Improves the soil structure. “The use of compost will help to alter the soil structure in the turfgrass root zone for improved availability of nutrients and water,” Rosenkranz says.
Adds organic matter to the topsoil. “It will also increase organic matter in the soil, resulting in a better soil structure,” she adds.
Builds up beneficial soil microbes
Reduces thatch
Smooths out uneven terrain from worm castings, freeze and thaw cycles, or water runoff
Reduces the need for fertilizing.
What Topdressing Material to Use
One of the first and most important steps is deciding what type of topdressing material you should use. To be effective and advantageous, it needs to be similar in texture to the underlying soil. According to the late James Beard, a leading authority on turfgrass, choosing the wrong material as a topper soil can create serious problems:
“The use of topdressing mixes containing textures drastically different from the underlying soil results in the development of a distinct layer that impairs air and water movement considerably and results in an overall reduction of turfgrass quality.”
He advises: “One of the most important considerations in topdressing is the use of a soil mixture of comparable texture and composition to the underlying soil.” The most common options for lawn topdressing are sand, topsoil similar to your existing soil type, high-quality compost, or a custom-blended mix of the materials.
Sand: Used extensively on golf courses, primarily on man-made greens. It can also be used with heavy clay soils to improve drainage. According to Rosenkranz, “homeowners should never topdress with sand,” so only do it if you know what you’re doing.
Topsoil similar to original soil: Adding a topsoil similar to the existing soil structure is acceptable and will help smooth out the ground but doesn’t contain much organic material. The best lawn topsoil for you will depend on your soil’s original characteristics. Topsoil for grass is a combination of clay, sand, decomposed plant matter, and other substances that compose soil.
Compost: “Compost is the best material for topdressing for all soil types,” Rosenkranz says, as long as it is finished and has few fillers. “As the compost drifts through the soil profile, it improves soil aeration and drainage, which improves the soil health,” she says.
Topdressing mix: It is common for homeowners to use a mix of the above materials to create a cost-effective blend that is comparable to their existing soil. Most often, a blend of compost and either topsoil or sand is recommended.
Materials can be purchased from local nurseries, garden centers, and perhaps landscape or construction companies if you are looking for lawn topsoil or sand.
When to Topdress Your Lawn
Timing matters as much as technique. Topdress while your grass is actively growing so it can recover quickly and grow up through the new layer.
“Topdressing can be done with lawn aeration during the spring or the fall when the plants are actively growing,” Rosenkranz says.
For cool-season grasses like Kentucky bluegrass and tall fescue, early fall is the sweet spot. For warm-season grasses like Bermudagrass and Zoysiagrass, late spring works best.
How often depends on your lawn’s condition. A healthy lawn only needs a full topdressing every few years, while bare or bumpy spots can be treated as needed. Topdressing too often raises the grade of your yard and can create new drainage problems, so go light and let each application settle before repeating.
Tips for Topdressing Your Lawn
Topdressing your lawn can be a do-it-yourself (DIY) project, but truthfully, it is a very labor-intensive endeavor. Some home improvement centers have motorized spreader machines available for rent, which will reduce the labor but increase the cost.
Routinely topdress: Topdressing regularly improves thatch breakdown and improves the soil. However, it does raise the grade of your yard. To ensure you don’t raise it too much, it’s best not to topdress your entire lawn routinely. Treat bare spots as needed and the entire lawn every few years.
Topdress the lawn more often: A very light topdressing application can be completed more often if the amount added is shallow enough to be brushed into core aeration holes.
Time it to your grass type: Topdress in the spring for warm-season grasses and in the fall for cool-season grasses. This allows three or four mows before severe heat or cold sets in.
Combine with other lawn maintenance practices: Combine topdressing with aeration to prevent soil compaction and overseeding to grow new grass. Keep in mind that the best topdressing for grass seed germination is rich in nutrients and peat-free.
If topdressing your lawn sounds like too big of a project to tackle yourself, some lawn care companies offer topdressing services to clients. It’s becoming a more popular service available because of demand but is still not widely available; it requires a lot of work with a small profit margin for companies.
How Much Material Will I Need to Topdress a Lawn?
The table below shows how much material you will need to topdress your lawn to different depths. If you have a particularly problematic lawn, it may take several applications to introduce enough material to achieve your goal.
It’s better to topdress multiple times than to overdo the amount of material and end up harming your lawn. “Only a thin layer of compost should be used. Too much can shade out the turf and can stunt the growth of the lawn,” Rosenkranz says.
| Depth of Topdressing | Amount Needed per 1,000 sq. ft. |
| 1/8 inch | 0.40 cubic yards |
| 1/4 inch | 0.77 cubic yards |
| 1/2 inch | 1.54 cubic yards |
*Consider purchasing 10% extra to account for filling low spots and material waste.*
Source: James Beard, “Turfgrass: Science and Culture.”
See Related: How to Measure a Yard
How to Topdress Your Lawn in 7 Steps
As a DIY project, the process isn’t difficult. It is tedious and labor-intensive, however. Follow these steps on how to spread topsoil over your lawn:
Check the soil pH and adjust accordingly if it is out of range.
Open up the thatch layer with a power rake or aerator to create channels for the topdressing material to penetrate the surface.
Mow grass as short as possible without stressing it to the point of damage.
Remove grass clippings, dethatching debris, or plugs of soil from aerating.
Spread grass seed if overseeding.
Add the topsoil to the lawn. The best way to spread topsoil on your lawn is by using your shovel. Shovel out a small amount of your material, working in small areas, a few square feet at a time. “Fling” the materials with a smooth, sweeping motion similar to hitting a hockey puck. Spread the topdressing over the lawn to a depth of 1/8 to 1/2 inch.
Gently rake it in or water the lawn well. That moves material down to the soil surface.
Once you have successfully topdressed your yard, it’s time to be patient, as it can take a few seasons to see the full results. If done correctly, you will see improvements in drainage and water retention quickly, but it takes time for the microbes to start working and the organic matter to begin breaking down.
Pro Tip: Fertile, rapidly growing turf and lawns that are more prone to create thatch build-up may require heavier topdressing rates.
FAQs
It’s optional, but yes, you can fertilize before topdressing a lawn. If you decide to aerate, the fertilizer should be put down after you aerate and before you place the topdressing material. This extra fertilizer boost will help increase the turf’s growth and health.
You should water your lawn after topdressing as this helps boost the terrain. Plants and grass can get stressed when going through a new change, and adding water afterward helps with the transition.
Do not mow directly after topdressing. It is best to leave the lawn alone for a week to 10 days before cutting the grass.
The difference between dirt and soil is that dirt doesn’t contain the living matter, organisms, humus, fungi, and nutrients found in soil. Dirt is made of silt, clay, and sand. Basically, dirt is a part of the soil that contains minerals but not live organic matter.
Improving Your Healthy Lawn
Topdressing provides a healthy and organic way to make your lawn look like the one in your dreams. All it takes is determination and elbow grease.
But even for small lawns, topdressing can be a lot of work. For help with your lawn care chores, LawnStarter’s landscaping pros tackle the topdressing, aeration, and overseeding, so you can enjoy the results without the backache.
Read More:
Sources:
- Ginny Rosenkranz, principal agent associate at the University of Maryland Extension. Salisbury, MD. Personal interview.
Main Image: Topdressing is applied into a bumpy lawn to level the surface. Photo Credit: Mike Hayward / Adobe Stock
Related Posts:
