Catnip: Indoor or Direct Sow Herb
How to Sow
Catnip may be grown from seed sown early indoors and transplanted outside after frost, or directly sown into the garden.
Sowing Seed Indoors:
- Sow catnip seeds indoors 4-8 weeks before the last frost in spring
- Sow seeds ¼ inches deep in seed-starting formula
- Keep the soil moist at 70 degrees F
- Seedlings emerge in 14-21 days
- As soon as seedlings emerge, provide plenty of light on a sunny windowsill or grow seedlings 3-4 inches beneath fluorescent plant lights turned on 16 hours per day, off for 8 hours at night. Raise the lights as the plants grow taller. Incandescent bulbs will not work for this process because they will get too hot. Most plants require a dark period to grow, do not leave lights on for 24 hours.
- Seedlings do not need much fertilizer, feed when they are 3-4 weeks old using a starter solution (half strength of a complete indoor houseplant food) according to manufacturer’s directions.
- If you are growing in small cells, you may need to transplant the seedlings to 3 or 4 inch pots when seedlings have at least 3 pairs of leaves before transplanting to the garden so they have enough room to develop strong roots.
- Before planting in the garden, seedling plants need to be “hardened off”. Accustom young plants to outdoor conditions by moving them to a sheltered place outside for a week. Be sure to protect them from wind and hot sun at first. If frost threatens at night, cover or bring containers indoors, then take them out again in the morning. This hardening off process toughens the plant’s cell structure and reduces transplant shock and scalding.
Sowing Directly in the Garden:
- Direct sow in average soil in full sun or light shade after danger of frost. In frost-free areas, sow from fall to early spring. Choose a location where vigorous plants can be easily controlled, such as in containers or a raised bed.
- Remove weeds and work organic matter into the top 6-8 inches of soil; then level and smooth.
- Sow seeds evenly and cover with ¼ inches of fine soil.
- Firm the soil lightly and keep evenly moist.
- Seedlings will emerge in 14-21 days.
- Thin to stand about 18 inches apart.
How to Grow
- Keep weeds under control during the growing season. Weeds compete with plants for water, space and nutrients, so control them by either cultivating often or use a mulch to prevent their seeds from germinating.
- Mulches also help retain soil moisture and maintain even soil temperatures. For herbs, an organic mulch of aged bark or shredded leaves lends a natural look to the bed and will improve the soil as it breaks down in time. Always keep mulches off a plant’s stems to prevent possible rot.
- Keep plants well-watered during the growing season, especially during dry spells. Plants need about 1 inch of rain per week during the growing season. Use a rain gauge to check to see if you need to add water. It’s best to water with a drip or trickle system that delivers water at low pressure at the soil level. If you water with overhead sprinklers, water early in the day so the foliage has time to dry off before evening, to minimize disease problems. Keep the soil moist but not saturated.
- Pinch the tops off young plants to encourage bushy growth. To encourage a flush of new growth, cut plants back by about one half after the first flush of bloom.
- Divide plants every 2 to 3 years to keep them vigorous and prevent them from spreading too much.
- Monitor for pests and diseases. Check with your local Cooperative Extension Service for pest controls recommended for your area.
Harvest and Preserving Tips
- Grow catnip for you feline friends, or use it yourself for a soothing tea. Leaves may be added to salads or to flavor foods.
- Catmints are marvelous as edgings for perennial beds and borders, as groundcovers under roses, or cascading over the edge of containers. They also attract numerous pollinators, and are great alongside the vegetable garden.
- Harvest leaves or whole stems as needed as soon as the plant is mature but before the leaves start turning yellow. Harvest in the morning before the heat of the day but after the dew had dried. Cut entire stems at the base of the plant. Strip leaves from stems.
- Store fresh catnip in the refrigerator for a few days.
- To dry, cut a bunch of stems on a sunny morning, tie them loosely and hang them in a dry, airy location out of the sun. Or, dry herbs in the oven for 2-3 hours on a cookie sheet at the lowest heat, leaving the over door open. Or, use a dehydrator following the manufacturer’s instructions. When plants are dry enough to store, a leaf will easily crumble between your fingers.
- When thoroughly dry, store herbs in a tightly sealed glass jar in a dry, dark location, such as a cupboard. Dried catnip can last for several months.
Common Disease Problems
Bacterial Leaf Spot: First signs are small translucent spots with a broad yellowish edge that slowly enlarge and become angular or irregularly circular with a reddish center. It thrives in cooler temperatures. The disease may also affect and disfigure flower heads. Burpee Recommends: Remove infected plants. Rotate crops with plants in a different family. Avoid overhead watering. Do not work around plants when they are wet.
Cercospora Leaf Blight: Small flecks which develop a yellowish halo appear on the leaves and turn brown and coalesce. They cause the leaves to wither and die. Burpee Recommends: Remove infected plants and destroy all plant debris. Rotate crops.
Root Rots: A number of pathogens cause root rots of seedlings as well as mature roots. Burpee Recommends: Pull up and discard infected plants. Make sure your soil has excellent drainage. Contact your Cooperative Extension Service for recommendations.
Septoria Leaf Spot: This disease is most severe during rainy seasons in closely planted gardens. Circular spots with gray centers and dark margins appear on the lower older leaves. Fungi spores are produced and darken the center of the spots. There is a progressive loss of foliage and fruits suffer from sunscald. Burpee Recommends: Remove and destroy infected plant debris. Don't handle or brush against plants when they are wet. Remove weeds growing nearby.
Virus (Various causes): The most characteristic sign of virus is tight and dark green mottling of the leaves. Young leaves may be bunched. Young plants may have a yellowish tone and become stunted. Burpee Recommends: Plant resistant varieties. This disease is readily spread by handling. Destroy diseased plants and the plants on either side. Never smoke in the garden as Tobacco Mosaic Virus can be transmitted from a smoker's unwashed hands while handling plants.
Common Pest and Cultural Problems
Aphids: Greenish, red, black or peach colored sucking insects can spread disease as they feed on the undersides of leaves. They leave a sticky residue on foliage that attracts ants. Burpee Recommends: Introduce or attract natural predators into your garden such as lady beetles and wasps who feed on aphids. You can also wash them off with a strong spray, or use an insecticidal soap.
Flea Beetles: These small hopping beetles feed on plant foliage and spread diseases. Burpee Recommends: Use floating row covers to prevent damage to young foliage.
Spider Mites: These tiny spider-like pests are about the size of a grain of pepper. They may be red, black, brown or yellow. They suck on the plant juices removing chlorophyll and injecting toxins which cause white dots on the foliage. There is often webbing visible on the plant. They cause the foliage to turn yellow and become dry and stippled. They multiply quickly and thrive in dry conditions. Burpee Recommends: Spider mites may be controlled with a forceful spray every other day. Try hot pepper wax or insecticidal soap. Check with your Cooperative Extension Service for miticide recommendations.
Thrips: Thrips are tiny needle-thin insects that are black or straw colored. They suck the juices of plants and attack flower petals, leaves and stems. The plant will have a stippling, discolored flecking or silvering of the leaf surface. Thrips can spread many diseases from plant to plant. Burpee Recommends: Many thrips may be repelled by sheets of aluminum foil spread between rows of plants. Remove weeds from the bed and remove debris from the bed after frost. Check with your Cooperative Extension Service for pest controls.
Whitefly: These are small white flying insects that often rise up in a cloud when plants are disturbed or brushed against. Burpee Recommends: They are difficult to control without chemicals. Try hot pepper wax or insecticidal soap. Check with your Cooperative Extension Service for pesticide recommendations.
Is catnip a perennial or annual? Catnip is a perennial plant that grows in zones 3-9. It is a member of the mint family.
How can I use catnip as a companion plant? Catnip can deter insects from members of the cabbage family.
Can I grow catnip in a container? Yes, in fact we recommend growing catnip in containers so it will not spread through the garden.
Are the flowers edible? Yes, the flowers may be used fresh or dried in herbal teas.
Why do cats like catnip? The leaves and stems of catnip contain an essential oil called nepetalactone, which is thought to emulate a cat pheromone. Catnip is often used in cat toys and causes behavioral changes when cats sniff the nepatalactone.