I am an avid gardener and I get asked this question all the time, the funny thing is the answer is so simple you will wonder why you didn't think of it. Put your finger in the soil of you plant up to about 1/2" if it's dry, water it, if it feel damp don't water it just yet. Also always use a pot with drain holes in the bottom and put a tray under it, if there is still water in the tray don't water.

This submission was not accepted into the wiseGEEK Writing Contest because it does not meet the minimum length requirement.