Nepetas or catmints (Nepeta spp.) are catching on as perennials and with their long flowering period, attractive coloration and dense growth, they’re bound to please. There’s just one problem: cats!
They don’t call this plant catmint for nothing: cats love it! That old feline favorite, catnip, is a nepeta (Nepeta cataria) and can draw cats from afar. They rub against it, scratch it and roll around on it. They’re attracted to the nepetalactone given off by bruised leaves and stems. And about two thirds of house cats are sensitive to nepetalactone.
Now, catnip (N. cataria) isn’t terribly ornamental and is usually grown for the pleasure of cats anyway, so that’s not usually a problem. But the other nepetas are ornamental plants. You don’t want cats scratching them to death or digging them up. True enough, they give off much less nepetalactone than catnip, but cats certainly can make a mess of them.
Try the following to ward cats off.
The problem is not with well-established plants, but freshly planted ones.
During planting, some roots are inevitably broken or leaves are damaged, leading to the emission of nepetalactone and the resulting cat attraction. So, cover freshly planted nepetas with some sort of barrier (a cut-off gallon milk jug, for example) to keep the cats away. After 4 or 5 days, the aroma accidentally released during planting will have disappeared and cats will no longer be a bother.
Your nepeta will then go on to live a beautiful, cat-free existence … unless you accidentally wound it or crush it, so keep your cat barrier handy!