How to grow and eat a bathroom sponge
There aren’t many mouth-watering veges that can also be a bath sponge and a dishcloth.
The luffa (or loofah) isn’t going to win any prizes for ornamentation, but this fascinating vegetable packs in more uses than most Western vegetables. The bath sponge is perhaps best known. When a luffa is fully ripened on the vine the flesh disappears, leaving only the fibrous skeleton and seeds. They are processed to remove everything except a network of xylem fibres, to make an absorbent and exfoliating back scrubber, bath sponge or loofa.
In Asia it is used for scouring pots – they call it the dishcloth gourd – and in making a range of products including mats and shoes. Powdered luffa is used in skin care products to reduce swelling and detoxify the skin. Before the Second World War, luffas were used as filters in US navy steam engines.
The same fruit, when immature, has a juicy, delicate flavour, similar to zucchini. It’s delicious drizzled with sesame oil and soy sauce or with the addition of browned garlic and slices of chilli pepper for more flavour.
There are two species of luffa: smooth
luffa ( Luffa cylandrica) also known as the dishcloth gourd, rag gourd or sponge gourd, and angled luffa ( Luffa acutangula). Both can be made into sponges, but smooth luffa is generally used because it is much easier to extract the fibrous skeleton.
Luffa fruit look rather like overgrown zucchinis or cucumbers. Angled or ridged luffas are dark green, 30-60cm long (although they will get much bigger given the chance), with 10 raised ridges running down the fruit. Peeling the ridges results in a pretty striped pattern.
Smooth luffas are normally 30-45cm long, and usually smoothskinned, though they can be slightly ridged. They are green and often lightly striped, tending to be larger at the lower end. They are generally much heavier than angled luffas.
Luffas are climbing annuals. Both species have large, deeply-cut leaves like a cucumber. In smooth luffa the young leaves are pale with silvery patches.
They’re amazing plants, growing up to 10m in a growing season. Given sufficient warmth, they make an excellent summer screen covering every inch of a substantial fence.