If you've already decided that topsoil is a needed amendment for your planting area, you may be considering whether you should purchase bagged mixes or buy in bulk from the supplier down the road. It may seem like a simple answer, but bagged and bulk mixes both have their benefits. Before choosing either, know what you're buying.
1. What is Topsoil?
As the name implies, topsoil is the upper level of soil. However, virgin topsoil is more of a rarity than cultivated topsoil, due to agricultural development. Cultivated topsoil may be in the second layer of soil, such as 5 to 12 inches below the surface. True topsoil is typically rich and fertile because of the organic material that has broken down over the years. It's often darker in color than subsoil because of the amount of organic material, but it may also be darker because it comes from wetlands.
2. Where is It From?
Knowing where the topsoil -- whether bagged or bulk -- is from is as important as any other factor in deciding which to purchase. Many topsoils are of local origin, meaning they came from your region. The soil labeled as topsoil may be from local farmland, which sounds great at first, but isn't always an ideal product for your lawn. Farm topsoil can contain high levels of pesticides used on the crops. Available topsoil may not be topsoil at all, but a collection of soils from different levels. Before purchasing either bagged or bulk topsoil, know where it came from and what the soil was used for.
3. What's in That Topsoil?
What the product labeled as topsoil really contains is one of the most important aspects of choosing. Many bagged topsoils are actually mixtures of organic materials, muck, peat, sand, topsoil and other ingredients designed to make the ideal planting medium. Some reputable nurseries and suppliers premix their own formulas that can be ideal for your region's soil type. Ask the staff at the nursery or garden center what the ingredients are. If they didn't mix it, contact the manufacturer of the product before adding it to your soil. Chances are that you'll be better off with a specially mixed, regionally designed formula of topsoil and other amendments than an unknown topsoil. As for bulk topsoil, inspect the soil for rocks or gravel and make sure none is larger than 3 inches in diameter. Squeeze some of the soil into a ball in your hand and make sure it forms a loose ball that holds together but is still crumbly; and make sure there is no construction debris or weeds growing in the pile.
4. The Nitty Gritty
Cost may be an important factor when deciding to buy bagged or bulk soil for your landscaping needs. A few bags will suffice for a small raised bed, but you may spend more on bagged soil for large areas than you would if purchasing in bulk. Buying quality topsoil will be more expensive either in the bag or in bulk, but the few dollars extra will be well worth the trouble it prevents. When choosing, ask for the recommendations of professionals in landscaping or your local university extension office. Your local bulk supplier may have a better understanding of the contents and origin of the soil, but the same may also be true for nurseries that make their own products.