I notice that you used to recommend vermiculite but you don’t anymore. Why?
El Cerrito, California

Vermiculite is hazardous material that contains asbestos. It is not worth the risk of using it.

Readers with grow questions (or answers) should send them to Ed at:
Ask Ed, PMB 147, 530 Divisadero St., San Francisco, California 94117, USA
You can also email Ed at [email protected], and send queries via his website at
All featured questions will be rewarded with a copy of Marijuana Question? Ask Ed. Sorry, Ed cannot send personal replies to your questions.