Last updated on October 23rd, 2023 at 09:02 pm
Catnip (bot. Nepeta cataria), also known as cat balm or cat weed, not only attracts four-legged fur friends with its scent, but is also a beautiful perennial for the natural or herb garden. Outside the flowering season rather inconspicuous, the plant shines meanwhile with its lush blooms in the most beautiful hues. Another plus: catmint successfully keeps numerous pests away and is therefore ideal as a protective companion planting for sensitive species, for example in the rose bed.
Origin and distribution
Catmint belongs to the catmint genus (bot. Nepeta), which includes about 250 different deciduous species of perennials. The majority of these are native to Asia and Africa, but have also been released into the wild in Europe since the mid-18th century. For this reason, catmint can be found in some regions of Europe, mainly along fields and roadsides. The diverse species occur naturally mainly in dry locations, but also on moist hillsides or in forests. Of the numerous species, about 20 are planted as ornamental plants in our gardens. They are popular mainly because of their long and intense flowering period, as well as their usefulness as insect pasture – not to mention that they are very low-maintenance plants.
Low-growing species of the genus, such as Nepeta racemosa, are wonderfully suitable for edging beds, as they form dense cushions and thus create a beautiful purple or white flowering border. Taller-growing varieties are perfect rose companions due to their filigree growth, especially since they keep pesky pests at bay. Therefore, species such as blue mint are very suitable as a substitute for lavender. But be careful: cats like to roll around in the plant, which is irresistible to them, and in this way can destroy painstakingly tended beds. To prevent this behavior, it is best to use the lemon-scented catnip (bot. Nepeta cataria), which is native to our area, as this species is avoided by four-legged friends.
Catnip in the garden
Catmints reveal their beauty only at second glance, making them perfect for a border or background planting. The mostly blue-violet or white flowering species accompany roses or create a calming counterpoint to showy perennials such as orange torch lily. In general, lushly flowering, tall-growing splendorous perennials or large-leaved plants are a perfect match for the more filigree and small-leaved catmints. Furthermore, the various species cut a good figure not only in the natural and medicinal garden, but also in boxes and tubs on the balcony or terrace.
Effect on animals
The flowers of catnip contain the scent nepetalactone, which is very similar to the sex attractant of some insect species and therefore magically attracts them. These are often beneficial insects such as the lacewing, which cannot resist the pheromone-like scent. Lacewings are important helpers in combating aphids, for example, which primarily attack roses.
Cats also find catnip very attractive – hence the European species name – and often like to roll around in this herb. This, in turn, is due to the ingredient actinidin, which is also excreted by non-spayed females with their urine and thus attracts and intoxicates male cats in particular. But be careful: catnip has such a strong beguiling effect on some animals that the four-legged friends become aggressive. If you observe such behavior in your cat, you should refrain from planting it in the garden as a precaution.
Even though the herb is irresistibly attractive to many animals, the scent reliably deters others. Especially pests such as mosquitoes, fleas or cockroaches flee from the lemony scent. Furthermore, catnip is suitable for deterring rats, especially in the form of aromatic oil.
Effect on humans
Many of the catnip species known today have their home in the Mediterranean region and spread with the Romans and their campaigns of conquest in almost all of Europe. Thus, Nepeta cataria also found a welcome home in our country and was cultivated in monastery and also peasant gardens more than 1000 years ago because of its healing properties. Medieval scholars and healers such as Hildegard von Bingen described Nepeta cataria, its effects and applications in great detail. Thus, common catnip was used for many purposes, such as stomach ailments and flatulence, to relieve infections, to clean wounds or to calm nervous conditions. In the garden, however, Nepeta cataria with its white flowers is rather inconspicuous, so that here mostly other species are used. By the way, the subspecies Nepeta cataria ssp. citriodora is especially recommended as a tea herb.
Preparation of catnip tea
As a tea, Nepeta cataria has a sleep-inducing, analgesic and antipyretic effect. To prepare it, take two tablespoons of the dried leaves, pour hot (but not yet boiling!) water over them and steep the decoction for five minutes. Depending on taste, the refreshing lemony-minty tasting tea can be sweetened with honey. For toothache, on the other hand, help a few fresh leaves, which you chew thoroughly.
Appearance and growth
Catmints belong to the labiates family (bot. Lamiaceae) and are divided into low and taller growing species. The leaves are silver-gray to fresh green and are arranged opposite on the stems, so that there are always two leaves at a height. The whole plant smells very intensely of lemon and mint.
The low varieties of catnip grow only between 20 and 30 centimeters high, but they grow strongly in width and can develop into lush cushions over time. These varieties are particularly well suited for edging beds or for understory planting in perennial borders.
With an average growth height of up to 60 centimeters, the representatives of the Nepeta faassenii group of varieties, which are crosses between Nepeta racemosa, Nepeta nepetella and other species, are somewhat larger. These varieties bloom a little later than the smaller representatives and are more loosely structured. The foliage is usually silver-gray in color. With a growth height of about 120 centimeters, the varieties of Nepeta grandiflora, the large-flowered catmint, which also has gray foliage, are considerably taller.
Flowering and flowering time
Most catmint species show their flowering splendor between April and July, although the flowering time can be extended again by a targeted, timely pruning. Depending on the species and variety, the plants bloom purple, blue, white or pink, with their filigree lipped flowers clustered in numerous narrow inflorescences. These sit on flower stalks up to one and a half feet tall.
Contrary to the fears of many a garden and cat owner, catnip is not poisonous to humans or animals – although it can sometimes induce intoxication-like states and should therefore be used only in careful doses. Instead, the young leaves and flowers can be used both medicinally and in cooking. The slightly sweet and minty tasting parts of the plant are great for smoothies, salads and summer desserts.
Location and soil
With the exception of a few species, catmints prefer a full-sun to sunny location in the garden – just as they do, after all, in their natural habitat in Africa or Asia. Otherwise, the perennials feel comfortable in a nutrient-rich, well-drained and sandy to loamy garden soil. This ideally has a neutral to slightly alkaline pH value between six and seven. The subsoil should be well loose and not compacted, as catmints, like so many other plants, do not tolerate waterlogging.
Planting catnip correctly
Catmints grow just as splendidly outdoors as in a balcony box or other planter – provided they are in a sunny spot. Since the small perennials can become very wide – some species even form runners – the planting distance should be about 30 centimeters, with the taller varieties even more. Therefore, calculate with about three to eight plants per square meter of planting area, depending on the species and variety. For container planting, on the other hand, the catmints may be somewhat denser. Dip the root ball in a bucket of water before planting to allow it to soak up moisture.
Watering and fertilizing
Most catmint species – not all – are very drought-tolerant plants that do fine without watering for long periods of time. Only in very hot or dry water you should reach for the watering can, but you should avoid waterlogging at all costs. Plants cultivated in containers, on the other hand, depend on a regular water supply and should always be watered when the top layer of substrate has dried off. Water in the saucer or planter must always be removed promptly, as the plants are very sensitive to this. Fertilization is also basically only necessary for potted plants, which you can provide with a weakly dosed liquid fertilizer for flowering plants during the main vegetation period.
Prune catmint properly
After the main flowering period – for most species and varieties this is over between July and August – cut the catnip back vigorously once, removing the faded shoots. The plants then develop an afterflower, a second bloom that can last well into the fall. If you want or need to impede the plants’ spread, another pruning is done in early spring.
You have several options for propagating catnip specifically. In addition to vegetative forms – such as by cuttings or division – you can also use purchased or self-collected seeds. After flowering, the perennials develop inconspicuous cloistered fruits containing up to four seeds, through which the plants may well self-seed.
Sow the seeds in a shallow container with a low-nutrient growing medium (7,00€ at Amazon*), cover them only very lightly with soil and place them in a warm and bright place. The seeds germinate best at constant temperatures around 20 degrees Celsius. Keep the substrate slightly moist with the help of an atomizer. After about two to three weeks the first green tips will appear and as soon as the seedlings have developed at least four leaves, you can move them directly into the open or into planters. However, do not transplant them outdoors until mid to late May when frosty nights are no longer expected.
Propagation by cuttings
However, propagation by cuttings, which you cut either between April and May or in early autumn, is quicker and less complicated. The shoots should be about five to seven centimeters long, and the lower leaves should also be removed. Root the little ones either in a water glass (change water daily!) or plant them right away in a container with a low-nutrient growing medium. The latter is more recommended, as it is easier. Transfer the young plants to a nutrient-rich substrate or to the desired outdoor location as soon as they begin to form their own new shoots. However, this should not be done before mid to late May due to the risk of frost.
Since catmints are perennial and often vigorous plants, they can be easily propagated by division. In any case, this procedure is recommended about every three to four years to keep the plants young and vigorous. Divide catmints by cutting out clumps of the desired size with a sharp, clean spade in early spring or early fall, lifting them out and replanting them in a new location. Dip the roots of partial plants in a bucket of water before replanting to help them take root.
Although many catmints originate from rather warm climes, they are nevertheless extremely frost-hardy in this country and very insensitive to the harsh winter weather conditions. Therefore, except for cuttings, no special protective measures are necessary for overwintering. Only specimens cultivated in tubs should be overwintered frost-free, but cool and bright indoors.
Diseases and pests
With regard to diseases and pests, catmints are very insensitive, because all parts of the plant contain the active ingredient nepetalactone. This has both an antiviral and antimicrobial effect and reliably puts annoying pests to flight – with one exception: slugs love to eat catnip, which is why you should protect a planting with slug fences or even slug pellets (€10.00 at Amazon*).
If you would like to plant catnip in your garden, but can’t spare a sunny location, simply plant Japan catnip ( bot. Nepeta subsessilis) or China dragonhead (bot. Nepeta prattii) in an off-sun, but still bright spot.
Species and varieties
In the garden, as well as for container culture, the following species and varieties of catnip are particularly popular:
Nepeta cataria ‘Citriodora’: strong scent of lemon, perfect for tea preparation, bushy growth up to 60 centimeters high, numerous white flower spikes between July and August, good repeat blooming
Nepeta x faassenii ‘Alba’: white-flowered variety with gray-green foliage and bushy growth, growth height up to 30 centimeters, flowering time May to August, suitable for dry locations
Nepeta x faassenii ‘Dropmore’: compact growing perennial up to 60 centimeters high with rather loose growth and violet-blue flower clusters between May and August
Nepeta x faassenii ‘Glacier Ice’: healthy, very robust variety with numerous whitish-blue flower clusters between May and August, bushy growth with growth heights up to approx. 50 centimeters
Nepeta x faassenii ‘Kit Cat’: bushy-growing, low-growing variety, up to a maximum of 30 centimeters high, many blue-violet to blue flower spikes between May and August
Nepeta x faassenii ‘Senior’: low-growing variety with a maximum height of 30 centimeters, cushion-like growth, good repeat blooming, many blue-violet flowers between May and August
Nepeta x faassenii ‘Six Hills Giant’: densely bushy growing, older and proven variety, up to 80 centimeters high, numerous violet-blue flowers between May and August
Nepeta grandiflora ‘Blue Danube’: variety of large-flowered catmint, bushy growth with heights up to about 80 centimeters, numerous violet-blue flower spikes between June and August
Nepeta grandiflora ‘Bramdean’: variety of large-flowered catmint, bushy growth with growth heights up to about 90 centimeters, numerous large, dark purple flower spikes between June and September
Nepeta grandiflora ‘Zinser’s Giant’: variety of large-flowered catmint, bushy, loosely branched growth with growth heights up to 80 centimeters, many blue-violet flower panicles
Nepeta grandiflora ‘Dawn to Dusk’: loosely bushy growing variety, up to about 80 centimeters high, numerous pale pink flower spikes between June and August
Nepeta nervosa: also veined catmint, up to 30 centimeters tall and just as wide, blooms between July and August in numerous light blue-violet flower panicles
Nepeta nervosa ‘Snow Bunny’: loose, compact growth with growth heights up to about 30 centimeters, striking pure white flower spikes between June and September, perfect as a rose companion
Nepeta racemosa ‘Grog’: variety of the racemose catmint, especially rich flowering variety with good after-blooming, numerous blue-purple flower panicles between May and August, bushy, low growth to about 30 centimeters high
Nepeta racemosa ‘Odeur Citron’: pretty, low-growing variety with blue-violet flowers between May and August, maximum height 30 centimeters, cushion-like habit
Nepeta racemosa ‘Snowflake’: cushion-like growing cultivar, maximum height about 30 centimeters and just as wide, many white flower spikes between May and August
Nepeta sibirica: strong-growing species with a preference for moist soils, up to 80 centimeters high, violet-blue flower spikes between June and July, good repeat bloom, runner-forming
Nepeta subsessilis ‘Sweet Dreams’: bushy growing variety with light pink flowers for semi-shady locations, growing height up to about 60 centimeters, abundant flowering between June and September