To the editor:
This letter is in response to Tim Lamprey’s recent article about adding “loam” to improve plant performance. First off, “loam” is a U.S. Department of Agriculture classification for soil texture — that is, the percentage of sand, silt and clay as the mineral component of soil. So, let’s stop calling soil loam. The most sensible approach for homeowners who have persistently poor plant performance is to have their soil tested. Universities such as UMass have very good soil labs and reports that can be easily understood by non-professionals. Soil report instructions will tell you exactly what to do to address soil chemistry.
The one approach that Tim does not mention, but is often most cost-effective to improve soil, is to increase soil organic matter content. Soil organic matter is the key to supporting healthy plants. It plays an important role in making nutrients available to plants, provides air-space for roots to grow and holds water so that plants survive even in drought conditions. If your soil organic matter content is less than 4 percent, add compost. Rent an aerator, spread a half-an-inch to an inch of compost and re-seed. You will see long-term positive results. Just make sure you do it in the spring or fall — not the summer. This should be the least expensive way to give you permanent results. Once root systems get established in cold climates like ours, soil organic matter maintains itself, so you should only have to do this once.
If and when you do buy “loam,” ask the supplier if they have a soil report on the loam. You will be able to see if it is good or not by reading the interpretation attached to the report. If they do not have a soil report, the safe fallback position is to insist that they provide you with “loam” that has compost added. This will ensure that you are not getting a pile of acidic sand, silt and clay that is devoid of organic matter and the ability to support plant life.