While Allium plants are perfectly fine for human consumption, they are poisonous to cats and dogs. You mustn't plant these perennials in a garden where your pets can easily access them. Just like you cannot give your pet food with onion or garlic in it, this plant is the same thing. Because this is an onion plant, feeding them to your pets is feeding onions to your pets. The best way to keep these plants away from your pets is to plant them in a container off the ground; so they do not have access to ingesting them.