Catnip, is a popular herb for your feline.  The crushed leaves release neptealactone, a compound known to cause frisky behavior in cats.  Oddly in humans it has a reverse affect and it calms us down.  The silver gray felted leaves are soft to the touch and borne below the tubular white/blue blooms.  Makes a nice container plant inside or outside.
Mature Plant Size: 24"-36" Tall, 24" Spread
Bloom Time: June-September
Light Exposure: Full Sun
Soil Type/pH: Well-drained/6.0-7.5
Hardiness Zones: 5-9 
Fertilizer: Incorporate compost before planting and normally they are fine for years.  Apply an all purpose granular (preferably organic) in poor soils.
Container Size: 4.5" Pot, 1 Plant