Can I use sand to break up clay soil and improve my lawn? -Gary
Sand is an important ingredient in the composition of soil (see What Is Dirt, Anyway?), but it needs to be balanced with organic matter in order to be of any benefit. Despite popular advice, you shouldn’t use sand by itself – that misguided practice is a cheap shortcut rather than a problem-solver.
When mixed together, sand and clay form a substance very similar to concrete, which will make your problem worse! Your soil would have to be more than 50% sand before it would start behaving like sandy soil – and sandy soil has drainage problems of its own.
You’re better off mixing your sand with compost or humus, at a 50-50 ratio, before incorporating it into your soil. Use the coarsest sand you can find (not play sand), with the largest particles, and mix it with well-rotted organic matter. If you aren’t able to do this step, you’re better off using compost alone.
What’s the disadvantage of using beach sand where that’s not illegal? I suppose the salt of the beach sand can be harmful to some plants and to earthworms, but f you wash the sand, that’d be ok, right?
I think the sand take up organic material from clay and make clay homogeneous, this leads concentrate useful heavy elements in the soil so the plant will absorb these elements.
You definitely can add sand to clay to loosen it but you have to add a lot to do any good. When clay dries its already as hard as concrete, so don’t worry that adding sand will make it worse. But golf course pros have found that it takes fifty to eighty percent sand to prevent soil compaction. And they note that it’s virtually impossible to effectively mix in that much sand onsite. Ideally clay should be twenty percent of the total mineral composition of the soil. Compost remains critical after that.
Thanks for sharing, David!