Catnip is an easy-to-grow perennial plant as far north as U.S. Department of Agriculture zone 3. Not all cats are attracted to catnip, but those who are will be seen sniffing and rolling on the foliage. Catnip can be dried for use in pouches as a cat toy and has other household uses, such as a component in tea and insect repellent. You can dry catnip and store it for use over many months.
Harvest when the plant is 8 to 10 inches tall. By that stage, the leaves will be large and mature.
Gather catnip for drying in late summer. The harvest process will depend on how you will be drying the catnip. If drying flat, then snip or pinch off the top leaves. If hanging the catnip to dry, snip off long stems.
Dry the leaves before storing them. Drying can be achieved by placing the snipped leaves on a screen to allow the air to dry the leaves, which can take several weeks. Another option to dry flat is to place the leaves on a baking sheet in the oven on the lowest setting; it can take up to six hours for the leaves to dry. The leaves are dry when you can easily crumble them with your fingers. To dry the leaves by hanging them, secure bunches with twine on the stems and hang them in a dry location.
Crumble the dried leaves and place them in an airtight plastic container or glass jar. The leaves can also be stored in a sealed plastic bag in the freezer.
Dry the catnip by securing several cuttings with twine and hanging upside down.
Combine catnip and olive oil in a clean mason jar and secure lid. Use approximately 1/4 oz. dried catnip to 1 cup oil.
Leave the sealed jar in a sunny window for several weeks.
Strain the catnip from the infused oil, and discard the dried catnip.
Store the strained catnip essential oil in a clean jar.
Let your catnip flower dry out on the catnip plant. This will happen at the end of the season.
Cut the flower off the catnip plant with a pair of scissors. It is best to cut the flower off, rather than pull it. This is because the seeds will be dried out and any sudden movements could cause them to fall out.
Hold your flower over a paper plate. Turn it upside down and give it a few shakes. The seeds will come loose and land on the paper plate.
Use your fingers to spring loose any remaining seeds that did not come out when you shook the flower.
Transfer your seeds to a plastic storage bag until you are ready to use them.
Plant catnip where it will be exposed to sunlight at least six hours each day. Although catnip will grow in partial shade, full sunlight will result in larger plants and bigger, brighter blooms. If you're growing catnip indoors, put it in a sunny window, or supplement available light with a grow light.
Cut the catnip plants down with a pair of scissors or garden shears after the first blooms have faded. Cutting the plant back will encourage the plant to grow and bloom again. Use the cut blooms in a bouquet, or dry the leaves and blooms by hanging them upside down in a well-ventilated room.
Water catnip regularly, but don't over water. The soil should be kept evenly moist, but not soaked. If the catnip is grown indoors, be sure to plant it in a pot with a drainage hole, and never allow the pot to sit in water.