That happened to my dad. His house was at the bottom of a hill. Every time it rained, a ' River ' would form from the top of the hill. It would wash everyone's ( from the top of the hill's) backyard furniture into his backyard, flow through his garden , then cause a waterfall off a brick wall on our neighbors drive way. The following year, about 20 feet away from where they were planted the year before, there were tons of tomatillo plants, self planted and moved. He never planted them again. They came back year after year. I had a similar situation with those ground cherries. Like sweet little orange tomatillos. The dropped from their plant and now are all over the place.