The correct answer to this question is NO. Generally speaking, not all herb plants are toxic to plants. However, there are a few herb plants which have been found to be toxic to cats and can cause serious health problems if grown while cats are around the premises.
Here are a few herb plants that have been found to be extremely dangerous for cats as they can cause cardiac failure, cardiac arrhythmias liver damage, temporary photosensitivity, bloody vomiting, diarrhea, hemolytic anemia, increased heart rate, and even death: Digitalis purpurea or foxglove, symphtum officinale or comfrey, hypericum perforatum or St. John’s wort, Valeriana officinalis or valerian root, menthe pulegium or pennyroyal, coleus ampoinicus or Indian borage or Spanish thyme, allium sativum or garlic, primula vulgaris or evening primrose, berberis vulgaris or barberry, hydrastis canadensis or goldenseal, cimicifuga racemose or black cohosh and caulophyllum thalictroides or blue cohosh.
