Question
Will adding granite to my clay soil help or hinder my efforts improve my soil? I'm hearing mixed reviews on this subject in central Tx

Answer
Dear Karo:

Decomposed granite is a rock powder and is an excellent amendment for clay soils.  All rock powders are great sources of minerals and micronutrients. All growing soils need them. As the microbes and macrobes like earthworms, digest the insoluble minerals, they break down into the various soluble micronutrients that all forms of plants need.

For example, limestone rocks are rich in calcium. Granite rocks are rich in potassium, etc. Seaweeds of course are the king of micronutrient fertilizers and soil amendments. There can be up to 70+ trace elements in seaweed.  In locations where seaweed is not readily available; rock powders is one answer to the problem.

Research continues to reveal that insoluble tiny particles like rock powder minerals, can be easily digested or absorbed via microbial activity, over time, into the anatomy of growing plants, thriving in the presence of rich organic compost, and other forms of powerful biostimulants like aerobic compost teas.

Sincerely,

Mack Jean
AllExperts
Master Gardener
Tennessee