The Garden Bug: Growing catnip
By Brenda Weaver
Set out catnip seedlings in a sunny, well-drained spot after the last frost of spring, spacing them 18" - 24" apart (some can grow to 5 feet tall). Water regularly, and pinch back any spindly growth to get fuller, more robust foliage. Outdoor cats can be rough on these plants, as they like to roll and lay on them; try placing bamboo stakes every few inches to prevent their destroying them. For "indoor" kitties, pick off a sprig and bring it inside for your cat to enjoy on the floor or in its favorite bedding.
Source: bonnieplants.com