Clever Gardening Technique
Skip the Gravel in Containers
It's a common misperception that placing gravel in the bottom of a pot before adding the soil and plants will improve drainage. Actually, the reverse is true. As the water seeps into the soil, it slows down as it reaches the gravel (water doesn't move readily from fine-textured to coarse-textured media), so the soil above the gravel -- where the roots are -- stays wetter than it would if soil filled the pot and could drain more easily out the bottom drainage holes.
A plant is only as healthy as its roots, so why don't we understand more about root systems? There are many surprising things to be learned in Roots Demystified by Robert Kourik (Metamorphic Press, 2008; $25). While the science may be interesting (at least to us plant nerds), the practical applications make this book useful as well.