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Easy Perennial Collection: Nepetas or Almost False Catnip

It always comes back to the same thing. Thousands of gardeners are looking for ways to garden… less! Yes, they want a beautiful flower garden. No, they don’t want to maintain it for hours. They don’t want to water and they don’t want the plants to be attacked by insects and diseases. And that’s not all: it must bloom all year round! These gardeners want perfect perennials, almost like plastic plants! Well, there are a few plants that meet some or all of these high performance criteria. Nepetas are part of this group.

The Nepeta’ Cat’s Meow ‘ in a beautiful ornamental flower bed. Photo: Proven Winners.

Catnip or Not?

Let’s immediately settle the big question that tickles your whiskers: is nepeta the real catnip? Yes and no. What is called catnip is actually a mixture of grass-like herbs, such as barley, wheat or oats. It looks a lot more like giant grass than nepeta. This catnip is very easy to grow indoors.

On the other hand, nepetas are also given the name of catmint or catnip. Because there is a species of nepeta, Nepeta cataria, which causes an euphoric effect on felines. This plant is so intoxicating that cats will actually lay down and roll over the plant. Finding plants or seeds of this other true catnip is relatively easy.

The species grown in the garden are not the same and generate a little less interest among the neighborhood kitties. That said, I myself have seen my own cat lay on my young ‘Walker’s Low’ nepeta plants. Eventually, the plant grew in strength and their relationship is now limited to a few chewed leaves and tender caresses.

The Basic Model

There are about five or six species of nepetas that are of horticultural interest. In fact, the genus Nepeta brings together more than 250 species, distributed mainly in Russia, Asia and northern Africa.

The majority of nepetas have greyish leaves and flowers in erect spikes. Photo: Proven Winners.

Most cultivars on the market are derived from Nepeta x faassenii , which itself is a cross between N. nepetella and N. racemosa. These hybrids form the typical catnip group. They are perennial plants with a rather rounded habit and which reach about 45 cm in height. Their foliage is toothed and rather triangular in shape. It is slightly graying and aromatic and releases a small mixture of mint and cinnamon. The stems of the plant are square, which is typical of the Lamiaceae family, to which nepetas belong.

The bloom rises above the foliage. There are hundreds of tiny mauve flowers gathered in aggregates or whorls. There are always new flowers developing, which explains the prolonged flowering of nepetas. It is a plant that establishes itself quickly and flowers on the first year of planting.

It is also important to underline the great ecological value of nepetas. They attract masses of pollinating insects of all kinds. It is also shunned by deer and wild rabbits.

Easy to Grow? Really?

The answer is yes, without hesitation. Nepetas are full-sun plants that have remarkable drought tolerance. They grow equally well in many types of soil, as long as the drainage is good. At planting, it is not even necessary to amend the soil. Nepetas grow well in poor soils. Once planted, there is almost nothing to do! A watering, if a great extreme drought persists, and that’s it.

Several years ago, nepetas had to be kept under surveillance, because they had the annoying habit of re-seeding themselves, if the conditions were right. Nothing really catastrophic: the plant was easy to control and we used these young plants to fill in the holes, by transplanting. Luckily, most newer strains (pretty much anything that has a kitty pun in their name) don’t have this defect.

How to Maintain Nepetas?

Since there are no problems with insects and disease, it really is a plant to watch grow. A little cleaning in the spring to remove the dead stems and it’s done.

The first flowering usually occurs between the end of May and the beginning of June. It lasts several weeks. To encourage the plant to flower until autumn, it is necessary to prune the faded flowers, to encourage the regrowth which will bear new flowers. Given the abundance of flowering, pruning the flower stalks one by one can be long. This is why, in my case, as soon as I feel a slight slowdown in flowering, I grab all the stems with one hand and with the other, I prune the whole plant at once. I remove about 25 or 30 cm of stems. The idea is to cut the plant back as much as possible, without compromising its beautiful full look. This action can give a shock, I agree. But after only a week, the plant grows new shoots and nothing shows. Then, thanks to this radical technique, the second flowering is as spectacular and as beautiful as the first. It will last until September, sometimes October.

The Different Varieties of Nepetas

There are nearly thirty species and cultivars available on the Canadian market and it must be recognized that for most of these varieties, there is no major difference. The typical portrait of the nepeta, derived from N. x faassenii , is to be a mauve flowering plant about 18 inches (45 cm) high and 18 inches (45 cm) wide. Several cultivars fit into this standard format with a few minor details: ‘Walker’s Low’, ‘Picture Purrfect’, ‘Cat’s Meow’, ‘Purrsian Blue’, etc. I grow ‘Walker’s Low’ and ‘Cat’s Meow’ side by side and it’s virtually impossible for me to tell the two varieties apart! For this group, it is often a matter of slight differences in height and width.

For example, ‘Junior Walker’ is a variant of ‘Walker’s Low’ which is shorter (40 cm) and wider (75 to 90 cm). It is therefore more interesting to create large nepeta ground covers. If you want a very low nepeta, less than 1 foot (30 cm) in height, ‘Cat’s Pajamas’, ‘Kitten Around’ or ‘Felix’ are the best choices. They will be perfect along borders of mixed perennials. Finally, although most nepetas grow in USDA zone 3, there are a few that survive further north in USDA zone 2: ‘Purrsian Blue’, ‘Cat’s Meow’ or ‘Blue Wonder’.

To explore a lesser-known side of nepetas, one must discover subsessile nepetas, also called subsessile catnips (N. subsessilis). With a height varying between 60 and 90 cm depending on the cultivar, the plant is more imposing, but just as easy to grow. The foliage is taller and less graying. The flowers are also generally larger and more intense purple than the classic varieties. It is PERFECT to cover a large area with a beautiful plant! With an average diameter of 2 feet (60 cm), you quickly fill a flower bed with a few plants! Those looking for a very imposing plant will choose ‘Blue Prelude’, a variety reaching 2 feet and a half (80 cm) in height and width. Another interesting fact, it is also here that we find plants whose flowers are not purple! ‘Candy Cat’ is lavender, while ‘Pink Dreams’ is pink!

Those who garden in USDA zone 4 can try their luck with nepeta ‘Blue Dragon’ (N. yunnanensis ‘Blue Dragon’). It is a large variety of 2 feet and a half (80 cm) in width and height and its port is rather upright. Then, collectors will enjoy discovering the nepeta ‘Souvenir d’André Chaudron’ (N. sibirica ‘Souvenir d’André Chaudron’), with its beautiful drooping flower spikes. It is a plant with a more erect habit. It’s sometimes sold under the name ‘Blue Beauty’.

Finally, we should also mention an old variety to rediscover, ‘Six Hills Giant’, 3 feet (90 cm) high. This was well-liked by professional growers until it was surpassed by ‘Walker’s Low’. A few attempts at golden-leaved nepetas have made their entrances (and exits), but nothing conclusive for northern gardeners so far.

In conclusion, all the plants that make up the large group of nepetas should be introduced into the low-maintenance garden. They are also valuable additions to the garden for pollinators. They are essential for xeric (dry landscape) gardening and they work wonders in gardens that simply want to be beautiful! What more?

Julie Boudreau is a horticulturist who trained at the Institut de technologie agroalimentaire in Saint-Hyacinthe, Québec. She’s been working with plants for more than 25 years. She has published many gardening books and hosted various radio and television shows. She now teaches horticulture at the Centre de formation horticole of Laval. A great gardening enthusiast, she’s devoted to promoting gardening, garden design, botany and ecology in every form. Born a fan of organic gardening, she’s curious and cultivates a passion for all that can be eaten. Julie Boudreau is “epicurious” and also fascinated by Latin names.

6 comments on “Easy Perennial Collection: Nepetas or Almost False Catnip

  1. Fascinating information, much enjoyed.

  2. Catmints are incredibly beautiful and useful plants but do watch for seedlings even form those reputedly sterile new varieties. Do beware of varieties offered by seed. I purchased seed from Chilterns in England many years back. ‘Blue Cloud’ is a big tall beautiful plant beloved by pollinators but as you say Julie, has an obnoxious penchant for seeding. We have been battling with it for years as it insinuates itself everywhere and then chokes out it’s neighbours.

  3. gardencat

    Don’t waste your time trying this at home if you have cats in your neighborhood. They will destroy it before it gets big enough to have a chance. I’ve even tried surrounding my little nepeta plants with chicken wire, and they still got dug up.

  4. Sue Babcock

    Probably too late for this year, but: would a variety/cultivar of this work well over my septic system’s leaching field – about 50’x50′, hard-pack sandy soil, good drainage, full sun exposure? Grass struggles on this patchy area…but not weeds or clover. I’ve given up with constant top soil/grass seed amendment/watering over the years. It’s smack in the centre of my front lawn, fully exposed to the elements.

    The leaching field standard depth in my area (E. Ontario, zone 4-5a)) is between 18″- 36″ so I would assume roots shouldn’t be an issue? And are potted/nursery seedlings preferred, or broadcast seeding in spring (given the area I’m trying to repair/reno)?

    • Carey Abbott

      How about dotting the area with threadleaf coreopsis? Mine are just coming into bloom now, and bloom for a good month and a half. Can shear off the tops, and they will bloom till fall. A nice, yellow easy to take care of plant.

  5. SANDY MARION

    Thanks, this is great! Would enjoy more articles like this. How about Bee Balm?

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