A perennial shrub plant, 25-30" (60-80 cm) high with a powerful root. On a fluffy, medium-sized bush, the toothed leaves have a lemon scent that attracts cats. It blooms with white or light purple flowers. The catnip is warm-loving and winter-hardy.
Catnip seeds have tough coats, and you'll improve the chance of success by first stratifying the seeds. Place the seeds in a plastic bag and keep them in the freezer for a month. Take them out and let them thaw, then freeze them again for another month.
Prior to planting, thaw the seeds in warm water overnight. Sow the stratified seeds in pots one to two months before the last spring frost. Plant them about 1/4 inch deep in seed-starting mix, and set them in front of a sunny window. They should sprout in two to three weeks. Harden off the seedlings before planting them in the garden, spacing them 18 to 20 inches apart. You can also keep them in pots to grow indoors.
Catnip can be planted in your garden in spring or fall, from seed or plants. It will sprout in two to three weeks if started from seed. Cutting back the plants after the first bloom set will allow enough time for them to completely regrow and bloom again. To avoid damage from unwelcome neighborhood cats, consider protecting your catnip with some type of enclosure.