Smithsonian Institute's Secrets of Soil
What's the difference between "rotten rock" and "parent rock"? (shhh ... I didn't even know there was "rotten rock.") This Smithsonian Institute website tells all... about soil. It carries over information from its exhibit "Dig It! The Secrets of Soil" that closed in January. Included are videos, interactive games and educational materials. Catch The Chef's Challenge Video, with Pierre La Terre and Sandy Marsh - Who knew sand could be so entertaining? (BTW... Parent rocks are primary minerals (quartz, mica, feldspar) that haven't changed chemically since they first crystalized. Rotten rocks are formed from particles of dissolved minerals. Rotten rocks form secondary minerals such as iron oxide, silicate clay.
Clever Gardening Technique
Build a PVC Grow Light Frame
Building a grow light frame using PVC pipe is within most people's budget. You'll still have to purchase the lamps, lamp fixture, and timer. There are build-a-frame instructions and video on the web. I constructed a simple, v-shaped frame with 1/2-inch pipe that holds one four-foot light fixture, easily raised and lowered.