Grow Your Own Tools. Some of the earliest domesticated plants were grown for tool use, just like these bottle gourds. While young gourds can be eaten fresh like summer squash, mature fruit that has completely dried on the vine has a hard shell. These sturdy forms have not only served as storage and dining vessels throughout history, they've also been blank canvases for artists who carve, paint, and embellish them. More recently, people have found that these gourds work beautifully as bird houses—especially for purple martins.