Not poisonous. some folks use it to worm their flocks. Not sure if it is effective. I have more than enough garlic. Never have to worry about the girls eating it all up. I let some of my garlic scapes mature every year. The little bulbils fall to the ground, and start new plants. It grows like a weed in my garden, and if it's in my way when I plant crops the next season, I just move it. Bet I don't have any nematodes!!!