Harvest catnip when it’s in bloom. Late morning is a good time to harvest after the dew has dried but before the day heats up and potentially causes the plant to wilt. Cut off entire stems or even the whole plant if you wish. Catnip plants are good for making actual catnip for your cat's enjoyment. Catnip is used dried in sachets, teas, cat toys, and more. Hang the stems upside-down for drying in a dark, dry, well-ventilated space as soon as possible after harvesting. Once they’ve dried out, which usually takes two to three weeks, the leaves and flowers can be crumbled for use., Catnip (Nepeta cataria) is a herbaceous perennial that thrives in much of North America and is very easy to grow. It has a clump-forming growth habit with square stems and triangular to oval, gray-green leaves with toothed edges that stretch around 3 inches long., Nepeta cataria, commonly known as catnip and catmint, is a species of the genus Nepeta in the mint family, native to southern and eastern Europe, northern parts of the Middle East, and Central Asia. It is widely naturalized in northern Europe, New Zealand, and North America. The common name catmint can also refer to the genus as a whole..