According to John: Add Sand to Clay and all you get are Bricks!
A popular gardening myth is that sand should be added to clay soil to improve it and make it lighter. In reality, unless it is added in monumental and impractical amounts, this practice will turn clay soil into a rock hard, mortar like substance. Organic matter, preferably quality compost, is a better choice to fundamentally change clay soil especially if you can add it once or twice per year for several years. It’s interesting to analyze why compost or organic matter can miraculously change heavy clay soil (or sandy soil for that matter). It is not that it does so physically although there is some minor, immediate physical improvement. The magic is in the organic compounds and the microbes that result from organic matter and are in compost that can fundamentally change everything about soil, for the better.
With this in mind, we recommend the John & Bob’s GrowGreen Smart Soil Solutions, which is a system of four products that provide the soil with organic compounds, beneficial microbes and food for microbes. These products can be re-applied every six months so heavy clay (and sand) can be improved on an ongoing basis. Since the magic is in the organic compounds and the soil microbes, we have put together a simple, concentrated system that applies only those needed ingredients. These concentrates are light and convenient so that money is saved in purchasing and in labor for application. They can be easily reapplied over turf, shrubs, and flowers and just watered in, so that the most important process of soil building and enriching can be ongoing.