Those with small children and pets should avoid planting the toxic datura, commonly known as Jimson weed, and castor bean. The seed in the fleshy red fruit of the yew, the nuts of horse chestnut trees ...

and like poison ivy, cashew plants contain a toxin called urushiol. It's found in the plant itself and the brown oil inside a nut's shell. It can cause burns, itches, and blisters, which is why ...