From tgray@california.com Fri Apr 16 14:18:40 1999 Date: Thu, 15 Apr 1999 23:50:14 -0600 From: t. gray shaw To: fronsk@cats.ucsc.edu, owner-permaculture@envirolink.org, permaculture@envirolink.org Subject: Re: Tires >I was re-reading "Urban Permaculture" and started thinking about the >growing potatoes in tires idea. I have heard of tires being used as >planters before. I was a little concerned that some strange chemical >from tires might get into the soil and then into the plant. Does anyone >know if there is anything to be cautious of when planting in tires? Any >feedback would be appreciated. Much thanks, >Kevin Snorf Yeah, I read in Erlich's _Ecoscience_ (or something else published around 1980) that 11,400 pounds of cadmium are released into the air each year in the United States from the normal wear of automobile tires. I don't know why that number stuck in my head, but I never forgot it. Of course, you'd have to figure what percentage one tire is of all the tires in the United States and make up some coefficient for the difference between "normal wear" and the fact that the tire in question is motionless (probably more if buried). I think it'd be easier to take direct readings under test conditions. I suspect that there are more volatile ingredients, anyway - otherwise why would they smell? Still, I don't see that whatever's coming off tires used as planters could be any worse for you than tap water, most household cleaners, and most cosmetics. So if you're going to apply a tight standard to tires, remember that you'd do just as well cleaning out your cabinets and buying a water filter. - Gray Never hold a Dustbuster and a cat at the same time.