Here is a luffa growing on the side of the carport. Two seeds planted in our raised garden produced hundreds of luffa vegys. You can eat them when they are the size of a zucchini but we didn't really like them.
After they dry out, here are the kids peeling them. Many mornings of rubbing the skin off and collecting the seeds
To this, a dried luffa - handy for all uses of sponges.