Have you ever heard about „catnip"? It is very often used to perfume toys for cats, but if you have the possibility to grow catnip in you garden, do it! Your cat will be delighted - and you as the gardener will take delight in its little blue or sometimes white or light pink blossoms. But beware for your cat‘s sake to grow the right plant: Catnip (nepeta cataria) and „catmint" (nepeta fassenii) are sometimes used interchangeably, but they are two different perennial plants of the mint family.
Catmint grows in soft mounds up to 2 feet (60 cm) high, has usually lots of blue blossoms and looks very nice - the most common plant (at least in Germany) is called "Six Hills Giants" - it has no effect on cats. But to my garden, as it grows like weed... Every year I cut it down after blossoming in summer so it blossoms in autumn again. And as much I try to collect all seeds (either to grow new plants, as a gift for friends or to sell at ebay), it spreads more and more... The original of „Six Hills Giants" is probably a smaller eastern mediterranean or middle eastern plant called „Persian Catmint" (nepeta mussinii), a fairly 1 - 2 feet hight (ca. 30 cm) groundcover with light blue blossoms.
The real Catnip however grows higher, at least 3 feet (up to 120 cm) high and looks more than balm-mint (melissa officinalis), having white or light pink blossoms. It has square stems in cross-section, opposite and fragrant gray-green to green leaves, small flowers in tight clusters at the ends of branches which produce four tiny, dark nutlets per flower.
I mean it COULD grow that high - if my cats let them grow... Every year I try to grow this plant again - and every year my cats destroy them before they reach their maximum height: they sniff it, lick it, bite it, chew it, rub up against it with head and chin, roll around in it, kick at it, and even leap about. Even my tom-cats act as a cat in heat. In one word, they go mad... No chance to stop them, they are deaf to my shuts and dizzy, drunk and on drugs... This lasts for several minutes, then the cat acclimates to it and needs a break: an exhausted cat sinks on the pitiful remains of former proudly standing plants to finish it off... Maybe an hour later the same reaction on those plants who‘d still survived occurs again.
Most cats react the same way, although not all of them. I don‘t now why, but some cats are somehow unimpressed... When Lea‘s kitten were young, they didn‘t take any notice of this plants as well as my senior cat.
But why do some cats go nuts? Catnip has aromatic oils (nepetalactone) in the stem and leaves which cause this signs - very similar to Valerian (valeriana officinalis) and other plants that contain actinidine. Catnip could be considered as a legal recreational drug for cats! But they don‘t suffer any side effects. So no first aid is required except for execessive ingestion which may cause vomiting or diarrhea.
Catnip is easy to grow. They just need full sun but moderate water and love well drained sandy soil. Propagation by seeds or division in spring. But I warn you: to protect young plants agains addicted cats you should use a wire-netting protection as agains rabbits... otherwise you‘ll never get high and healthy plants ;-) Usually you need no frost protection, and whether you cut them in late autumn or not it‘s up to you. If you do so, you may pick the leaves and dry them, filling old socks with it as a winter toy for your cats.
For the questions of hardiness and easy of care I gave my answers having no addicted cat in mind... Otherwise see above ;-)
