I live in Grapevine, Tx, between Dallas and Ft. worth. A neighbor has seedlings (numerous!) of Cow Pen Daisy. I was considering planting a few in my perennial bed. I can deal with a prolific reseeder, but recently read that this plant produces chemicals that kill other plants that grow too close. Well...how close is too close? Would this be a problem for established plants, or just other seedlings or newly planted things? Does anyone have info on this?
