Lawn Topdressing: What is it and its Benefits

Eden explains topdressing in detail in this article, along with the different materials used for topdressing, the advantages and disadvantages of each material, and the overall benefits of topdressing the lawn. Let’s start with understanding what exactly topdressing is.

What is Topdressing?

Top dressing a lawn is the practice of spreading a thin layer of a single or blended material over the lawn to either amend the soil or to level the lawn. This layer of material is less than half an inch thick and is spread over the area by scooping the material with a shovel and throwing it over the area. The topdressing material is spread evenly over the lawn area by raking it lightly using a garden rake or a bow rake. 

Topdressing can be done for the entire lawn or for the bare spots only to fill them by combining topdressing with overseeding, depending on the requirement. One of the best features about topdressing is that it can be done without removing the existing layer of grass, as the grass will be able to grow through the thin layer of topdressing material. 

What are the Materials Used for Topdressing?

The three most common and effective materials for topdressing are good quality sand, topsoil that has similar characteristics to your existing soil, and compost. These three materials can be blended together in the right ratio to form a fourth topdressing material. Let us look at each of these four topdressing materials in detail.

1. Sand

Sand is a commonly used topdressing material on golf courses to improve the resiliency of the turf. When using sand on home lawns, you should be careful to apply a thin layer and spread it evenly. You should only use sand as a single topdressing material to cover tree roots that are exposed and to repair excessive thatch buildup.

The advantages of using sand as a topdressing material are given below.

• Sand improves the drainage of the soil and prevents waterlogging.
• Sand can help lawns that experience a lot of foot traffic to recover from the stress faster by cushioning leaf tips and crowns.
• Sand helps make a lawn more firm. When there is a lot of organic matter present in the soil, it makes the lawn spongy, which is not ideal as it can turn into a breeding ground for insects. Sand helps improve the firmness of the lawn.
• If your lawn faces problems due to thatch buildup frequently, using sand as a topdressing will help reduce thatch.
• Sand also improves soil aeration along with soil drainage and this helps keep the root zone of the grass healthy.

The disadvantages of using sand as a topdressing material are given below.

• Sand cannot be used in heavy clay soils as sand creates a cement-like substance when it combines with clay.
• Heavy and uneven applications of sand create lumps that choke the grass and inhibit their growth.
• When the sand is too fine, it seals the soil and prevents water from penetrating to the roots of the grass.
• If the sand is too coarse, it does not blend well with the existing soil and frequent applications will cause nutrient loss as sand does not retain nutrients.

2. Topsoil

Topsoil refers to the top few inches of the soil (about 2-8 inches or 5-20 cm) that is rich in nutrients and organic matter and is formed by the slow weathering of rocks over hundreds of years. Topsoil helps improve the quality of in situ soil when added. Topsoil is smooth and easy to apply but you should ensure its characteristics are similar to your existing soil when you use topsoil as a topdressing material.

The advantages of using topsoil as a topdressing material are given below.

• Topsoil helps correct unfavorable soil conditions like lack of nutrients or a high composition of sand.
• Topsoil helps smooth out the lawn.
• Topsoil helps level uneven spots in the lawn caused due to soil erosion.
• Topsoil is the best material to use to prepare an area for overseeding or reseeding as it has a good nutrient content and correct soil pH.
• Topsoil improves soil drainage as it allows water to pass through its layer and down to the root zone of grass.

The disadvantages of using topsoil as a topdressing material are given below.

• Topsoil can contain fertilizers, lime, and other substances which when combined with the components of your existing soil might harm the quality of the soil instead of improving it. For example, if your soil already contains enough nutrients, the added fertilizer of the topsoil will cause fertilizer burn to your plants. Also, if your soil pH is in the pH range and you add lime to it in the form of topsoil, it will lower the pH of the soil and make it too acidic. Therefore, you need to test the topsoil before application.
• Since topsoil is also soil, it can contain weed seeds which will be introduced into your lawn if you do not screen the topsoil before you add it.

3. Compost

Compost is a mixture of organic ingredients that is used to fertilize the soil and improve its nutrient quality. Composting is done with two categories of material – greens and browns. Brown waste includes twigs, branches, and dead leaves while green waste includes coffee grounds, fruit and vegetable waste, and grass clippings; animal manure is also added to the compost pile. When using compost as a topdressing material, it is important to ensure that the particle size is fine and similar to the particle size of your existing soil. Also, the pH of the compost should be in the range of 6.5 to 8.0.

The advantages of using compost as a topdressing material are given below.

• Compost is a natural fertilizer that corrects any nutrient deficiencies in the soil.
• Compost has a neutral pH and hence does not affect the existing soil pH.
• Compost improves soil drainage.
• Compost releases nutrients slowly into the soil which is best for the health of the grass and thus keeps them nourished for a long time.
• Compost has beneficial microorganisms that break down the nutrients in the compost and make them available in the soil for the grass to absorb. Also, the microorganisms feed on thatch and break it down and thus prevent thatch buildup.

The disadvantage of using compost as a topdressing material is given below.

• Since compost is made of decomposed organic matter, it can get easily contaminated due to harmful insects, bacteria and viruses. Therefore, it is essential to screen the compost before application.

4. Blended Mix

A blended topdressing mix is a mix of all three individual topdressing materials – sand, topsoil, and compost in a certain ratio as per the requirement of the lawn. The mix can be bought as a ready-to-use mix or you can buy the individual components separately and then mix and prepare them in the proportion you require.

The advantages of using a blended topdressing mix are given below.

• The sand in the topdressing mix improves drainage and prevents thatch buildup.
• The topsoil in the topdressing mix helps level any uneven areas and fill bare spots in your lawn.
• The compost in the topdressing mix improves the nutrient quality of the soil without affecting the soil pH or chemical composition.
• A blended mix allows you to choose the ratio of the materials you want to add to your lawn which is effective in meeting the specific needs of your lawn.

The disadvantage of using a blended topdressing mix is given below.

• A blended topdressing mix is more expensive than using compost on its own.

If you want to know the detailed procedure of how to top dress a lawn, read Eden’s article on the same.

Which is the Best Top Dressing Material for my Soil Type?

It is important to choose the right topdressing material according to your soil type because choosing the wrong material can harm your lawn instead of improving it. For example, if you apply sand topdressing to a heavy clay soil, the two materials will combine to form a cement-like mix that will prevent circulation of air, nutrients and water in the soil. 

To choose the best top dressing material for your soil type, you need to first understand what type of soil you have. The most basic way of determining your soil type is taking a lump of soil in your hand and rubbing it between your palms. 

If the soil feels sticky in your hands, then it has a high clay content; if it feels gritty, then it has a high sand content and if the lump of soil feels soft and fine, then it is loamy soil. 

For more information on different soil types and how to identify them, read Eden’s article – Guide to Soil Types

Benefits of Topdressing the Lawn

Top dressing a lawn has various benefits when done properly with the right material for your soil type. Eden lists the benefits of topdressing your lawn below.

• Improves soil quality: Topdressing improves the overall quality of the soil by providing nutrients like nitrogen, phosphorus and potassium, organic matter and increasing the soil’s capacity to retain these nutrients.
• Reduces the need for chemical fertilizers: Since most topdressing materials contain organic matter that improves the soils nutrient content, it reduces the need for chemical fertilizers.
• Improves soil aeration: Topdressing loosens the soil by modifying its texture and thus improves soil aeration to allow better flow of nutrients, air and water in the soil.
• Breaks down thatch: The organisms present in compost feed on thatch to break it down and prevent thatch buildup. This also helps improve soil aeration.
• Adds beneficial microbes to your soil: Compost has beneficial microbes that are added to the soil during topdressing. These soil microbes break down the compost to make the nutrients available to the soil and also help balance nitrogen, phosphorus and potassium levels in the soil.
• Aids healthy seed germination: Topdressing provides ideal soil conditions for reseeding or overseeding a lawn and this aids healthy seed germination.
• Levels the lawn: Topdressing helps to level the uneven lawn spots caused due to irrigation or drainage issues as the topdressing mix has similar characteristics as the existing soil.

Is Topsoil the Same as Topdressing?

No, topsoil is not the same as topdressing. Topsoil refers to the top few inches of the soil while topdressing material refers to any of the materials mentioned above like sand, compost or a blended mix. Topsoil is just one of the topdressing materials and on its own it can be used to level the uneven areas of the lawn or provide high-quality soil for reseeding or overseeding a lawn.

Can I Put Topsoil Over an Existing Lawn?

Yes, you can add topsoil to an existing lawn. When topdressing to level uneven lawn spots, topsoil is spread over the existing lawn in the low spot to increase the level of the area half an inch at a time and bring the spot to the same level as the lawn surrounding it. 

If you want to topdress a lawn but don’t know how, don’t have the tools or if your physical health does not allow it, contact Eden’s topdressing service. Our experts bring their own equipment and material and provide professional high-quality service that is guaranteed to improve your soil quality and give you a lush, healthy lawn.