OP. Grow your own sponge! A fantastic way to become more self-sufficient, and kind on the environment. Originating in Southeast Asia, specifically, India, China, and Vietnam, and gradually spreading to Africa, the Middle East, and the Americas, the luffa has rich cultural roots. The name "aegyptiaca" came from European botanists in the 16th century after Johann Veslingius, in 1638, named luffa the "Egyptian cucumber” after seeing the plant in Egypt. The word luffa was taken from the Egyptian-Arabic name لوف lūf in the 17th century. Also known by the names, Chinese okra, Smooth Luffa, Loofah, Loofa, and Vegetable Sponge. There are two distinct types of Luffa grown, this one is predominantly grown for its spongelike fibrous interior, which has a gentle exfoliating affect and can be used in both the kitchen and bathroom in place of synthetic sponges. Although, when young and less than 17cm long this luffa can be eaten, it is typically Luffa acutangula that is cultivated as a food and prized in Asia. Prepare in ways you would courgette, kamo kamo or okra, the fruits flavour is reminiscent of courgette or cucumber. Requires a long hot growing season. We have struggled to grow luffa outdoors for years in our mountain climate, only ever getting a couple of mature fruit. This season we grew them in our tunnelhouse and successfully replicated the tropical temperatures they prefer. If you have a warm climate, you will be blessed with plentiful smooth, elongated light green fruits with a length ranging from 30 to 60cm. Annual, vine habit like cucumber.
Indoors: Germination can be tricky, needs hot temperatures constantly between 20 and 30°C and a long season to make a sponge. Soak seeds for 12 hours in warm water then sow seeds in pots or punnets 1cm deep and place in warm position. Transplant out at 50cm diagonal spacing. Outdoors: Soak as above then plant on small mounds approximately 2cm deep in groups of 3 or 4 seeds per mound. Pinch out plants when trailers reach 150cm to keep within bounds and promote fruiting. Fruits will produce a better shape if the plant is trained up a frame. Luffas will dry on the vine if you leave them there long enough, as ours are in the tunnelhouse we used this technique for curing them. Alternatively, harvest and lay them somewhere dry and airy to cure making sure to keep an eye on them. When the skin turns brown it can be easily peeled off leaving the fibrous inner, some recommend soaking the whole fruit in warm water for a few minutes first to make removing the skin easier. Cut off the tips and shake the seeds out and give a thorough wash to clean it. Luffa sponges are likely to have natural brown markings on them; shop-bought luffas are bleached. Matures 70 days from transplant.