When Prunella is born with a purple thumb instead of a green one like her parents, everyone's stumped. What could it mean? Before long, they find out. Prunella prefers corpse flowers to carnations, fungi to ferns, and poison ivy to petunias. The stickier and scarier the plant, the more Prunella loves it. And if her poisonous and noxious garden keeps the other neighborhood kids away, it's probably for the best. But then one day, a curious weed of a different sort pops up. Should prickly Prunella uproot this tentative new friendship or allow it to flower?