Here are some frequently asked questions about topsoil in gardens.

If you have poor quality soil, you may want to lay a new layer of topsoil over your existing soil. However, many people are not all that familiar with topsoil, why it is used, or how they can know when it is needed. Here are some frequently asked questions about topsoil in gardens that may help answer some of your questions.

What is Topsoil?

Topsoil is the outermost layer of soil, generally the top two inches of your soil. Topsoil contains the most nutrients and microorganisms, which will help your plants grow and establish their roots. Unfortunately though, there are places that lack topsoil, or don't have a thick layer of nutrient-rich soil. In places such as this, you will have to bring in soil to create a topsoil layer.

Why Should Topsoil Matter to Me?

If you have plants, trees, bushes, shrubs or grass in your yard, topsoil should matter to you. It ensures that all of these growing and living plants have the nutrients they need to thrive and grow. Without good topsoil, these items may die as soon as you plant them or fail to thrive over time.

How Do I Know if My Topsoil Layer is Good?

As mentioned above, there are places where there really is not much of a topsoil layer, or any topsoil layer at all. In these cases, you will want to bring in quality soil to create your own nutrient-rich soil layer. There are circumstances where this is done regardless of the quality of your topsoil, such as when grass is being laid. It is important that the layer is thick and nutrient-rich so the grass thrives, so landscapers often create an entirely new layer, even if your existing layer is good. However, if you or a landscaper are planting trees, shrubs or bushes, the topsoil layer is tested. Soil testing can help determine whether your topsoil layer is sufficient or if a new layer needs to be created before the plant can be planted. Soil testing kits are sold at most garden centers and home improvement stores.

Do I Need to Continue to Test After My Plant or Tree is Planted?

If you did not have a topsoil layer at all and/or your plant is planted in an area where the soil may slide off due to water runoff, you should continue to test the soil. If the condition of the soil was poor to begin with, it is unlikely that topsoil will change the conditions. Once the plant uses up the nutrients in the soil, more nutrients will need to be added to ensure the tree of plant has the nutrients it needs to survives. Usually, you will only need to add the nutrients themselves, rather than changing out the topsoil. However, if the pH level of the topsoil is off, you may need to replace the topsoil itself.

Is it Difficult to Add Topsoil?

No. Although testing sounds confusing, it is simple. And once you have determined that topsoil is needed, the process of adding it and spreading it is also easy. You can buy bags of topsoil at a garden center or home improvement store, or have it delivered to your home by the truck load. You then pour the topsoil where you want it and spread it out with a hoe or rake, trying to ensure your layer is at least two to three inches thick. Once it is spread, your space is ready for grass to be laid or plants to be planted.