Essential Topsoil Truths You Should Know to Help Your Garden Flourish
Using the right topsoil, and caring for it correctly, is key to having a healthy lawn, flowers, plants, trees, and shrubs.
If you enjoy gardening it's worth considering how to improve the quality of the topsoil in your backyard. After all, plants rely on topsoil, the uppermost layer of the earth's surface, for water and necessary nutrients. The more organic matter it has, the darker the soil will look (like what you may see sold in bags or bulk as "black dirt"). This type of dirt is very easy to dig in and support healthy plant growth. However, the type of soil in your yard may look very different. Depending on your region, it can vary from reddish clay to beige sandy soil.
Topsoil Myths & Misunderstandings
If you've ever found yourself in a garden center, staring in bewilderment at all the bags of soil amendments, there are a few things you should know. Here are four common misunderstandings about topsoil that can trip you up.
Topsoil Myth 1: All Topsoil Is Pretty Much the Same
Topsoil can differ dramatically, even in the same yard and from one garden bed to another. All the dirt in your yard is made up of sand, silt, and clay in various amounts with a generous helping of decomposed plant matter (organic matter). The right mix provides nutrients, allows for good drainage, and lets enough air reach the roots, creating an ideal place for plants to grow. Sometimes topsoil has weed seeds in it, so don’t be surprised if you have to work at eliminating them for a year or two after you start a new plot or bed.
Topsoil Myth 2: If My Soil Is Rich, I Don't Have to Fertilize
Plants draw the nutrients they need to grow from the soil. Those nutrients need to be replenished each year for the healthiest growth, no matter what type of soil you have. This is especially true for annual flowers and vegetables, which can be real nutrient hogs. Luckily, it's easy and inexpensive to restore nutrition annually by adding high-quality compost and/or granular or liquid fertilizer products.
Topsoil Myth 3: I Can Use Dirt From My Yard For a New Garden Bed
You can, but in most cases, you probably shouldn't. Soil includes varying amounts of decomposed plants, called organic matter. It's the component that gives topsoil good drainage and its loose, easy-to-dig quality. Most soil around homes doesn't have nearly enough organic matter, which is why gardeners often buy topsoil to add to their garden or have to amend their soil with organic matter like compost.
Purchasing topsoil is the quickest way to great garden soil. You can put it directly on top of existing soil. For best results, put down a layer of 2-3 inches of topsoil on your planting beds and till it deeply into the existing soil. The other alternative is to amend soil by tilling in generous amounts of compost. This can be a lot of labor, but ultimately it can create very productive soil.
Topsoil Myth 4: To Always Have Good Topsoil, I Have to Till It Annually
Once you create a garden or raised bed filled with good soil, avoid walking on the soil and compacting it; you should not need to till it every year. If you’ve built raised beds, you’ll never need to step into them. If you created a garden that is not raised, create permanent paths so that you don’t compact the soil you’ve worked hard for. To add nutrients and to replace organic matter as it breaks down, add 1-2 inches of compost after cleaning up your garden in the fall; it will be ready to go in spring.
Common Topsoil Questions
Where Can I Buy Topsoil?
Topsoil is widely available through a variety of sources, including garden centers, nurseries, and home improvement stores. Your topsoil should be screened; this means any extra materials such as small rocks, roots, and debris have been removed. Topsoil is sold by the bag or in bulk. Bulk orders of topsoil are usually priced by the cubic yard, and the price varies based on location and availability.
How Do I Figure Out How Much Topsoil I Need?
If you need to fill a raised bed or install a berm, you will need to measure the area's square footage and depth to calculate cubic feet. To fill a garden bed, you’ll probably want at least 6 inches of depth of topsoil. To install a new lawn, plan to spread a layer of 3-6 inches of topsoil before sowing seed or laying sod, depending on the quality of your existing soil. A soil test can help you determine if your existing soil will support good lawn growth.
Can I Use Topsoil in Containers?
You shouldn't because it is heavy and won't drain as well as you would need it to in a pot. Stick with potting soil for containers, and use topsoil in garden beds.