Is Greater Knapweed toxic to cats?

No — greater knapweed is listed by the ASPCA as non-toxic to cats. It is a sensible choice for a home with a cat; a curious nibble will not poison them, though no plant is meant to be eaten. Centaurea scabiosa is not individually listed by the ASPCA, but the genus is consistently non-toxic to companion animals: the ASPCA lists cornflower (Centaurea cyanus) and Russian knapweed (Centaurea repens) as Non-Toxic to dogs and cats. Treated as pet-safe on that genus grounding; certain Centaurea (e.g. C. solstitialis) pose a risk to horses, not dogs or cats.

Yes — the ASPCA lists greater knapweed as non-toxic to cats and dogs. A cat that chews a large amount of any foliage can still get a mild, brief stomach upset, so discourage grazing, but it will not be poisoned.

The ASPCA classification Growli uses applies to both cats and dogs: Greater Knapweed is non-toxic to dogs as well. See the full greater knapweed pet-safety guide for both species.

Reliable ASPCA non-toxic picks for a cat home include spider plant, calathea, parlor palm, peperomia, and most true ferns. Browse the best cats-safe plants list to check more before you buy.