Photo courtesy of kurafire at flickr.com.
Many gardeners aren’t aware that granite dust — that’s right, powdered granite — serves as an excellent, all-natural fertilizer that’s rich in potassium (a.k.a. potash), the “K” in NPK. Potassium concentration in commercially available granite dust can vary from as low as 3% to as high as 11%, depending on where it’s mined. Also available are “fortified” granite dusts, which contain other materials intended to boost the N and P factors as well. The extra ingredients in fortified granite dust may include greensand (another potassium-rich product mined from former ocean-floor deposits), fish meal, chicken manure, and blood meal, as well as several other types of fertilizers.