There are weeds between them too, all the other plants in my garden are roses. A poisonous weed is a possibility I just don't think it's likely, and I have way too many daylilies to be able to find evidence of him chewing or not, he likes to crawl right in the middle of them. I obviously can't be 100% certain in this case, but I definitely don't feel right about my cats playing in them anymore.