Many people use the terms topsoil and loam interchangeably, mistakenly thinking they are the same thing. This can lead to some difficulties when you are landscaping your yard and designing new vegetable gardens and flowerbeds. If you are planning to revamp your yard and garden, there are some things you should know about topsoil and loam before you begin.
What is topsoil?
Topsoil refers to the top layer of soil that covers your property. This may consist of clay, sand, or silt or any combination of the three soil particles. Because there is no legal definition for topsoil, there is no guarantee of the ratio of soil particles and no guarantee the soil will contain organic matter, explains the Michigan State University Extension. The makeup and consistency of topsoil varies depending on where you buy it. To get an accurate picture of the topsoil you are purchasing, you will need to visit the site and observe the soil for yourself. Because some suppliers simply dig the topsoil from the ground and deliver it as is, it may contain rocks or sticks that you will need to remove before using the topsoil. Some suppliers screen the topsoil to remove foreign objects and add organic matter or fertilizers, but they are not required to do so. Topsoil is typically sold in bulk and is less expensive than loam.
How do you use topsoil?
Topsoil is typically used to fill in sunken areas or build up the level of soil in your lawn or landscape. Topsoil can be used to create a level surface for building raised beds, positioning ornamental lawn and yard features, or increasing the drainage in soggy areas. It may be used to create pathways or to make a base for setting stepping stones. Topsoil generally serves to level the ground in your yard and to fill in areas around stone walls or other features of your landscape. It can even be used to create slopes to direct rainfall away from your home.
Topsoil can also be incorporated into existing gardens to improve the condition of the soil, but beware of topsoil that has been scraped from the earth and has not been screened. This raw soil may contain foreign objects, stones, roots, and other debris. It may also contain copious amounts of weed seeds. If you are purchasing topsoil to build up a garden bed, remove any sticks or rocks from the topsoil first and apply a two- to three-inch layer to your garden. Till the soil into the top four inches of your garden soil and then add the remaining topsoil. This creates a transition layer that allows your flowers and veggies to send roots deep into the soil. Be sure to test your new soil and add nutrients as needed for the best growth of your plants.
What is loam?
Loam is a special kind of topsoil that consists of clay, sand, and silt particles. Loam also contains organic matter and minerals needed for plant growth. Ideally, loam contains equal parts of clay, sand, and silt. Loam that contains more than 50 percent sand is called sandy loam while loam that contains more than 30 percent clay is called clay loam. Loam with more than 30 percent silt is called silty loam. As a rule, flowers and vegetables grow best in loam with ample amounts of humus from decayed organic matter. Loam may also contain fertilizer, limestone, or other nutrients to balance the soil's pH and promote healthy plant growth. Loam may be sold in bulk or pre-packaged in bags. It is more expensive than topsoil.
How do you use loam?
Loam is used to fill raised beds and large container gardens and to enrich the soil in vegetable and flower gardens. Loam improves drainage, loosens the soil, and also helps with adequate water retention. It should be worked into the existing soil when added to gardens, as this encourages roots to grow deeper where they can access water and nutrients. Garden loam is not suitable to use alone in pots and small containers, as it compacts easily when watered, making it difficult for your plants to get the moisture and nutrients they need to thrive. If you choose to add garden loam to plant pots and containers, mix the loam with equal parts peat moss and perlite to create a lightweight soil ideal for container plants.
If you are unsure whether topsoil will serve your needs or whether you need garden loam for your projects, talk to a landscaper and explain your needs. They can help you make the right decision for your project. Click here for info on a landscaping company.