How to Grow Catnip From Seed (Tips for Fast Germination!)
Despite what many people believe, catnip isn’t only useful for cat owners! Catnip can also be used to repel a variety of pests in the garden. You can even use it for cooking just like mint. So if you want to cultivate your own catnip, familiarize yourself with its needs!
Catnip seeds usually take 4–7 days to germinate. The growing medium needs to be moist growing medium and kept in a warm environment with an ambient temperature of about 86°F or 30°C. Catnip can grow indoors or outdoors from seed in zones 3–9, with temperate and tropical conditions. Catnip is best kept in big clay or plastic pots.
Quite frankly, I find that some cats are actually fussier than catnip—and I say this with no exaggeration whatsoever. So if you’re looking for a low-maintenance herb that’s versatile, go for catmint. Continue scrolling to find all there is to know about planting catnip!
How Do You Germinate Catnip Seeds?
Although very small, a single catnip seed can easily grow into a 3–4 feet tall hardy plant. Overnight soaking before direct sowing is not needed. However, pre-sprouting catnip seeds in a moist paper towel in a warm area can speed up germination.
Catnip seeds look a lot like specks of black pepper. Upon closer look though, they kind of resemble black mung beans. Rather than being completely black though, catnip seeds are a very dark shade of brown.
There are over 3900 catnip seeds in an ounce, which is equivalent to more or less 140 tiny individual seeds for every gram.
You can buy a packet of over 1000 catnip seeds (here on Amazon) for just under 5 bucks. But if you want to start your very own herb garden, get the package of heirloom catnip seeds along with several other tasty and fragrant herbs below on Amazon.
Now, although some say catnip seeds should be soaked overnight before sowing, it’s not really necessary. In fact, many home gardeners have been able to successfully germinate catnip seeds by directly planting them in the soil.
Learn more in our article on successful seed germination!
Ideally, a catnip seed should be sown in moist fertilizer-free soil—I’ll explain why later on. It should be lightly covered with a very thin layer of soil, no thicker than 1/8 inch. Then, lightly spray with clean water to moisten the soil and sown seeds.
For germination, temperature is more important than light exposure. More specifically, lower temperatures prolong germination and higher temperatures speed up germination.
So although you can grow catnip between 60–70°F (15–21°C), you can expect to wait for up to 6 weeks before seeing a tiny catnip sprout. Bumping the temps to 71–86°F (21–30°C) helps catnip seeds grow rapidly within 1–3 weeks.
Regardless, it’s quite difficult to tell whether the sown catnip seed is indeed viable when it’s buried in the dirt. So ensure seed viability by pre-sprouting a couple!
Pre-Sprouting Catnip Seeds (5 Easy Steps!)
Generally, pre-sprouted catnip seeds germinate in less than 10 days. As such, many experienced gardeners and experts recommend doing so over directly sowing them.
Follow these simple steps to pre-sprout catnip seeds:
- Tear a sheet of power towel and give it 2–4 spritz of clean water.
- Spread the catnip seeds on the moist towel and fold it in half.
- Place the folded towel in a resealable air-tight container like a plastic zip-lock bag.
- Spray some more water until the towel becomes slightly translucent and seal it.
- Keep the sealed container in a warm area, like on top of a working refrigerator.
If it’s especially cool in your area, you can use a heat mat and a thermostat like the combo deal below on Amazon to keep the seeds warm and make sure it germinates fast.
After all that, it’s a waiting game. If you notice that the paper towel has started going opaque again, it’s drying up. So give it a couple more spritz to keep the seed moist and promote germination.
Oftentimes, you’ll see the seeds germinate by day 4 or 5. With that, you can finally plant each catnip in its own container and watch it flourish.
Where Should You Grow Catnip Seeds?
It is possible to grow catnip indoors and outdoors in plant hardiness zones 3–9 at any time of the year. However, planting catnip in spring in summer leads to better and faster growth. Keep catnip in a container for better control of its weedy habit.
A huge part of the reason why catnip—or catmint—is so easy to grow could probably be attributed to how it’s widely distributed and naturalized throughout the world.
Catnip is a herb that can thrive in temperate and tropical areas with little to no problem. It can even tolerate both heat and frost!
So technically speaking, you can plant catnip no matter the season. As I’ve mentioned before though, catnip grows faster with warmer temperatures.
In other words, sowing catnip seeds anytime between spring and summer typically results in rapid development.
Young catnip plants, however, don’t compete well with other plants and weeds. Even though they’re hardy, catnip seedlings can suffer from slow and stunted growth when placed next to more mature plants.
Much like many other plants in the mint family, however, established catnip plants can grow widely when planted directly in the ground. It’s even considered an invasive species in certain areas including West Virginia because of this.
Discover the basics in our article on taking care of grown catnip plants!
When and How to Harvest Catnip
Catnip is best harvested once flowers are in full bloom in the middle of summer or fall. Using clean gardening scissors, cut as many catnip stems as needed while leaving at least 4–5 inches (10–12 cm) of the plant to encourage regrowth.
You can harvest your catnip once it’s 1 foot tall. However, you’ll have to wait for its flowers to open up if you want it to be as tasty and fragrant as possible. Depending on what variety you grew, you can expect to see clusters of little white, pale purple, or blue-violet blooms!
But don’t wait too long before harvesting flowering catnips. Once the flowers start drying up and falling off, the aromatic property of the essential oils in catnip will greatly and steadily decrease.
If you don’t need too much, just harvest what you need. In doing so, you can harvest twice every year instead of only once before winter starts. Get as much oils in your harvest by snipping catnip during mid-morning hours in the height of summer.
Promote fuller, bushier regrowth by leaving a few inches of the catmint above the ground. Make sure to leave at least one set of leaves on it as well. These will allow it to grow back again in just a couple of weeks.
When done, shake the debris off your cut catnips. Alternatively, you can give it a quick rinse-and-shake to clean off any dirt. To be safe, pat them dry to remove all excess water. A salad spinner would also work great for quickly drying it off.
Also, you can keep the flower clusters separately for seed-saving. Just wait for the flowers to start withering on their own and then cut them off before they completely dry out.
2 Ways to Store Freshly Harvested Catnip
The best ways to store catnip leaves after harvesting are 1) dried and kept in air-tight containers or 2) chopped up and frozen into ice cubes with some water. Either way, catnip leaves should be consumed within a year.
Quite honestly, my friends and I don’t really notice a significant difference for either one. However, if you’re planning to stuff some catnip into your little kitty’s toys, it’s best to dry them. I mean, you don’t want their toys to be soaking wet, do you?
After you’ve successfully harvested a good bunch of fresh sprigs from your catnip plant, inspect them for insects hiding within and underneath the foliage. Wash them and pat them dry if necessary.
Then, carefully remove the leaves from the stems. Let them all dry on a mesh tray in a room with no windows allowing direct sunlight in. After all the catnip has thoroughly been dried, store it in an airtight container.
Others have also had great results by using the microwave or a food dehydrator. Just keep in mind that microwave-dried catnip will become a lot less fragrant and flavorful since it loses a lot of its essential oils in the process.
Besides that, harvested catnip leaves can also be stored by freezing them into ice-cubed herbs. Just keep in mind that frozen catnip cubes should be used immediately after they’re thawed. They can’t be frozen again.
If you want a less troublesome option that doesn’t require chopping in up and portioning it out, I’ve got the thing for you!
Just chuck your cleaned-and-dried catnip sprigs and leaves directly into a resealable plastic bag before keeping them in the freezer. It’s important that they aren’t wet when you do this. Otherwise, they could freeze up together.
What pests can catnip repel?
Various harmful insects and damaging herbivores can be repelled with live catnip plants. Such pests include aphids, squash bugs, flea beetles, mosquitoes, ticks, flies, termites, and deers. Catnip contains a natural pest-deterring compound called nepetalactone which is commonly used to make commercial pest repellents.
How can you stop cats from killing catnip plants?
To prevent house cats from destroying live catnip plants, they can be grown in hanging baskets to keep them out of reach. Additionally, potted catnip can be protected using old bird cages, empty aquarium tanks with screen tops, and thick chicken wire mesh. When space is available, the catnip can be grown away from cats in a grow tent or greenhouse.
Is catnip toxic for humans and animals?
Despite minimal side effects, certain varieties and cultivars of catnip are indeed considered toxic to humans and pets including cats. Catswort (Nepeta cataria), in particular, is known to be mildly toxic when eaten in large quantities. It can cause vomiting, diarrhea, drowsiness, disorientation, and hyperactivity.
Summary of How to Grow Catnip From Seed
Catnip can be grown from seeds and sown directly into the ground anytime between spring and summer for fast development. To further speed up germination to just 1 week or less, pre-sprouting with moist paper towels and resealable plastic bags in a warm environment is recommended.
It’s best to harvest catnip leaves and flower stalks early in the morning during the summer or fall months. Prevent it from dying back completely by leaving at least 4 inches of stems with leaves. Home gardeners can preserve their catnip for long-term use by either drying or freezing it.
- “Catnip and Catmint” by Jeff Schalau in Backyard Gardener
- “Production of Catnip in North Carolina” by Ferguson, Weeks, and Fike in Purdue University Center for New Crops & Plant Products
- “Catnip” by Cheryl Kaiser and Matt Ernst in University of Kentucky Center for Crop Diversification
- “Growing herbs in home gardens” by Jill MacKenzie and Shirley Mah Kooyman in University of Minnesota Extension