Inexpensive Bagged Topsoil is Bad for Gardens
Q: I just had a beautiful stone-raised bed built across the front of my house. It is 17 feet long, 12 feet wide, and 3 feet high. I have been filling it with soil: first from my yard but then with bags of the inexpensive topsoil from a local home center. I hope to plant a Japanese maple in the center. When getting another load of bags the guy helping load my car said this was absolutely the wrong soil to be using. I thought topsoil was supposed to be good dirt. I am very distressed after so much work. I do not want to stunt the growth of the tree, nor do I want to remove all the soil that I have added.
A: I know you have made a big investment in labor and soil material, but I think the landscape person was right. Inexpensive bagged topsoil is rarely any good. In my observation, it is usually composed of poorly composted wood chips, silt, and sand. This mix will not support good plant growth. In addition, having different layers of materials in your raised bed will make for a very poor rooting environment. The expense of your nice Japanese maple could be wasted.
I can’t think of a solution other than removing the material in the bed and replacing it with good-quality topsoil from a landscape supply company. Examine the soil before it is delivered to be sure it’s a homogenous brown, sandy loam. Another soil option is to have big super sacks delivered to your site. Erthfood (erthproducts.com) and Soil3 (soil3.com) are two local producers. A third option is to use good quality but more expensive bagged products from the local home center. I have the good results of my experience with these products at bit.ly/GAbaggedsoil.