Having fresh catnip at your disposal is important when you’re a fur parent. It’s also a great addition to herb gardens in general. Regardless of the reason you’re growing it though, you need to know what they need to stay alive. Otherwise, you’ll find yourself constantly buying a new pot from the nursery!
Catnip plants grow best with 1) large clay pots, 2) sandy soil, 3) weekly watering, 4) full sunlight, 5) temperatures at 68–86°F 6) humidity at 50–70%, and 7) no fertilizer. Catnip is a low-maintenance herb whether grown indoors or outdoors.
Now you’re probably thinking that catnip is not a low-maintenance one. However, remember the figures above are, as always, the ideal conditions for the plant to grow and it can really survive in a large variety of conditions making it an easy plant to grow.
This means, that you can still grow healthy and thick catnip plants as long as you grow them while keeping 7 important factors and guidelines in mind. Keep reading to learn more!
It is recommended for catnip to be grown in a medium size planter such as 12-inch (30 cm) wide that allows the plant to grow without requiring any planter change. Unglazed clay planters are recommended with drainage holes and catch plates.
Keep in mind that catnip can grow pretty tall and bushy. So it’s best to give it a lot of room to grow while also making sure that it won’t be too difficult to move when necessary. A wide but relatively shallow planter like this one on Home Depot will work well for catnip.
That said, it’s not like you need to grow your catnip from seed in a large container from the very beginning. Many of my friends and acquaintances have grown catnip in small pots that are typically used for nursery plants or small succulents and cacti.
However, keeping catnip in tiny 4-inch pots won’t allow it to thrive. You would need to transplant it once the seedling is about 6–8 inches (15–20 cm) tall—which can kill the plant.
Discover why it's risky in our article on herbs dying after repotting.
Similar to many other herbs, catnip doesn’t like being in constantly wet and soggy soils. It’s best to have it growing in a planter that prevents excess water from sitting at the bottom. Unglazed clay and terracotta pots are perfect for this. Plastic pots are a close second.
Either way, the planter should have drainage holes to ensure that the soil won’t be soaking wet—which could suffocate your catnip and cause root rot.
Even in nutrient-poor dry soil, catnip can grow into a fully developed plant with no issues. However, it grows best in mediums that drain well so sandy soil mixes will work great for it.
More often than not, herbs require a soil pH of 6–7.5. Catnip plants, however, grow well not only in neutral soils. They can also thrive in acidic and alkaline soils.
Hence, you don’t have to buy expensive specialty potting mixes to keep your catnip happy and healthy. It can survive in soil with little to no nutrients without much problem.
Just stay away from ready-to-use potting mixes that contain slow-release fertilizers. They can do more harm than good for our hardy herbs.
Know the differences among these in our article comparing sand, silt, and clay!
As long as you give it a well-draining mix, you won’t have to worry much about its soil quality. So when you do create your own potting mix, prioritize draining.
Nevertheless, I know people who have successfully grown bushy and healthy catnip plants with other mediums such as clay pebbles, moss, perlite, coco coir, bark, and seed-sowing compost. Of course, hydroponics is also an option!
The drought-tolerant catnip prefers dry soil, generally needing water only once a week when established. While still small, catnip seedlings may need to be watered every other day.
Sure, catnip needs water to grow and survive in harsh growing conditions. But this doesn’t mean that its soil should always be left soaking wet. Rather, catnip only requires low to moderate watering.
Like I’ve discussed before, overwatering catnip—especially when it’s still really young and vulnerable—can easily result in its death. You don’t want to wait until your catnip wilts before you start watering it either.
During the germination period, catnip seeds and seedlings require frequent watering, often done 3–4 times per week. However, when they’ve grown tall and have produced several leaves, watering can be done once a week at most.
The top 0.5–2 inches of a catnip’s soil should have thoroughly dried before it is watered again. When the soil is still moist to the touch, check it again the next day to see if it has dried before watering again.
Allow water to soak into the soil to deeply and evenly water your catnip. Then, stop once the water drains out of the pot’s holes at the bottom and or sides.
By following these tips, even beginner home gardeners can avoid drowning their catnip.
Remember, however, the catnip plants grown in containers outdoors may require more water than ones kept indoors. This is especially true for people living in more tropical regions with really hot summers. It is best to move potted catnip indoors when it rains though.
Catnip grows best with at least 6 hours of direct sunlight exposure each day. Grown indoors, it can be placed near south-facing windows or under 15–40W grow lights.
Because it’s a light-loving plant, catnip grows best with natural unfiltered sunlight outdoors. It can tolerate partial shade, but it grows best with a minimum of 2–6 hours of full sun exposure.
That said, catnip is one of the many herbs that can be grown completely indoors with little to no issues whatsoever.
Ideally, it should be placed no farther than 2 feet away from a window that gets a lot of sun during the day. South and southwestern windows, in particular, are perfect for growing catnip indoors with natural light.
Bright windows facing the east or west with indirect sunlight also allow for good growth in catnip. Remember to regularly turn their pots in such cases to avoid leggy development.
Gardeners living in apartments or condos with little to no windows for natural can opt to use grow lights placed at least 6 inches above the plant instead. A fluorescent grow light system like the one below from Amazon, can help you grow big bushy catnips at home.
Have it on for 12–18 hours a day, and you’ll be ready to harvest in no time!
Looking for something more cost-effective? Consider getting a full spectrum LED grow light (here on Amazon). These last longer, use less energy, and produce little to no excess heat.
For a flourishing catnip, maintain warm growing temperatures from 68°F to 86°F (20–30°C). It can survive in lower or higher temperatures but will grow slower or spindly.
If you ask cat owners with green thumbs from across the globe, then you’d know that catmint can thrive in a wide variety of growing conditions.
Be it in temperate North America and Europe or tropical Eastern Africa and Southeast Asia, catnip can prosper with sufficient light, water, and drainage.
Catnip can survive really cold winters at -30°F (-34°C) and its foliage is quite frost-hardy. Alternatively, this minty herb can also handle very hot summers over 100°F (37°C).
You should also have a reliable digital air or ambient thermometer (here is a good one on Amazon) on hand for easier checking whenever you need to.
To avoid lasting negative effects such as stunted or leggy growth, keep an eye out for the weather forecast in your area—especially during extreme summers and winters.
Even mature catnip is somewhat intolerant to high heat. So place it in the shade before noon on sweltering summers.
Make sure that your outdoor potted catnip will also survive through harsh winters by either covering it with a protective barrier against frost or bringing it inside the house.
Catnip grows well with moderate levels of humidity around 50–70%. Hence, it can grow with average room humidity indoors.
Here, we have to consider, once again, that catnip doesn’t like too much moisture in its environment. That includes not only the soil it’s grown in but also the air surrounding it.
In short, catnip will not grow optimally when the humidity is either too high or too low. Although they can withstand such environments, they can still die from prolonged exposure to such substandard conditions—even more so when it’s too humid.
You want to give your catmint the sweet spot between the two. As the story of Goldilocks and the three bears goes, you want the humidity for your minty herbs just right!
So if the average humidity in your area stays well below 70%, you can grow it outdoors with no problem. But be mindful to place it away from areas with plenty of standing water like fountains or ponds in the yard. Water features can boost the humidity in the area.
When inside, you can also reduce humidity by opening windows and positioning your potted catnip away from your other plants, especially humidity-loving houseplants. Ample air circulation will prevent high humidity.
On the other hand, if it’s too dry you can raise the humidity of your catnip. Place it next to other plants, lay its pot on top of a saucer with wet gravel, or invest in a good humidifier.
Regularly fertilizing catnip seedlings and mature plants is unnecessary. Catnip should only be fertilized only in case of extremely poor soil.
Though many think that all plants need fertilizer, this isn’t necessarily true. Catnip, for instance, is a herb that will do better without any fertilizer than with regular application!
Yes, catnip is considered a moderate nitrogen feeder by experts. However, it’s typically only fertilized when grown commercially on a large scale. I’m talking about acres of land here.
For such cases, nitrogen and other nutrients are incorporated into the soil before planting it. Besides that, side-dressing catnip is a normal practice as well. They do this to ensure good growth and minimize potential profit loss.
Plus, even when they are given plant food, it’s done rarely. Usually, catnip is only fed nutrients once per growing season because they don’t require it. More specifically, flowering is induced by poor soil rather than nutrient-rich alternatives.
As a regular home gardener though, you don’t have to worry yourself over such things!
It’s best to grow catnip from seed using lean soil—that is, soil with little to no nutrients. Despite promoting lush growth, fertile soil can reduce the characteristic flavor and fragrance of herbs like catmint!
Compared to mint, catnip is already quite mild tasting and smelling. So do yourself a favor and retain those lovely qualities by refraining from giving your plant fertilizers, which it doesn’t need.
Learn about other plants in the mint family in our article on spearmint and peppermint!
How can you propagate catnip?
Catnip can propagate on its own by allowing flowers to bloom and self-seed. However, this method can lead to invasive and weedy growth. For better control and management, it’s best to propagate catnip by collecting its seeds, using stem cuttings from mature plants, and dividing the root system in half before replanting them separately.
Do you need to mulch catnip?
Normally, catnip doesn’t require mulching regardless if it’s grown outdoors in the ground or a pot indoors. But in cases of extreme weather events, mulching can help keep catnip plants alive. In very hot and dry summers with water shortage, mulching helps retain moisture. Mulching catnip during freezing winters prevents it from dying back.
Are catnip and cat grass the same thing?
Catnip and cat grass are two different plants. Catnip is a relatively low-growing herbaceous plant with serrated heart-shaped leaves that are used for teas and repellents. Meanwhile, cat grass is a weed-like plant that can grow up to 6 feet tall and used is as livestock feed. However, they have similar growing needs such as lighting and watering.
Summary of How to Grow Catnip From Seed
Grow catnip indoors or outdoors by using a 12-inch clay pot with holes at the bottom that’s filled with well-draining sandy or rocky soil. Provide proper care by watering it lightly or moderately once a week and exposing it to 6-12 hours of natural or artificial light.
Promote optimal growth and retain its minty taste and smell by keeping catnip in an environment with temperatures and humidity levels staying within 68–86°F and 50–70%, respectively. Do not fertilize it. Otherwise, its flavor and scent will be lost.
- “Nepeta” by n/a in North Carolina State University
- “Catnip, Nepeta cataria” by n/a in Wisconsin Horticulture
- “Catnip” by Cheryl Kaiser and Matt Ernst in University of Kentucky Center for Crop Diversification
- “Herbs” by n/a in Clemson University Cooperative Extension
- “Growing herbs in home gardens” by Jill MacKenzie and Shirley Mah Kooyman in University of Minnesota Extension