Catnip (Nepeta cataria) is a member of the mint (Labiatae) family of plants. It is a perennial herb. The plant is even distantly related to the marijuana plant. Catnip is native to much of Europe and Asia but has quickly taken over native areas and become common in both the United States and Canada. There are more than 250 varieties of catnip available. Catnip contains a chemical (Nepetalactone) that acts on the cat's olfactory senses and works as a stimulant when inhaled by the feline.
Plant catnip in full sun or dappled shade. Catnip will adjust to virtually any well drained soil. If the soil is a sandy loam, the catnip aroma will increase dramatically. Catnip enjoys a mildly acidic soil with a pH of 6.1. Work peat moss into the soil at a ratio of 50 percent peat moss with 50 percent garden soil prior to planting. Remove all weed growth from the soil prior to planting.
Sow catnip seeds in the late fall or early spring. If winters are hard, then early spring is the best time to sow catnip seeds. Lightly sprinkle catnip seeds on the soil and cover with approximately half an inch of soil. Water lightly to settle the soil. Catnip can be started indoors if there is a fear of a late hard frost in the region. Start seeds indoors in a plant-start soil mixture and small flats. Once the plants reach five to six inches in height, transplant outside.
When catnip is approximately 5 to 6 inches tall, thin the plants. Each clump should have approximately 12 to 18 inches of space between each other. Catnip grows between 3 to 5 feet in height depending on the variety.
Watering and Fertilizing
Water catnip regularly to maintain moist soil conditions. Fertilize catnip monthly during the growing season. Use a well balanced fertilizer such as 10-10-10. Apply lightly according to the directions on the label. Water thoroughly to work fertilizer into the soil.
Cut catnip back after flowering in the fall. Remove the flower heads and discard. Apply added mulch around the base of the catnip before the winter arrives. Apply approximately 3 inches of mulch such as peat moss, recycled plastic, bark chips or sawdust.