Luffas are frost tender, but will grow successfully in a wide range of climate zones down to at least the climate zone that includes Hamilton. They grow like a cucumber with intriguing upright flowers, and once autumn comes they can be picked and left to dry out. They are attractive plants and the flowers are clearly much loved by bees and other insects.
Once they are dry, and the seeds rattle inside, you can peel off the skin and shake out the seeds to use as a pot scrubber, body scrubber, etc. If they look stained and discolored, just soak in a hydrogen peroxide solution or similar. (15)