Growing up to a metre long this luffa can be eaten when young, or allowed to mature to make a bath sponge.
Sometimes known as sponge gourd, the luffa (or loufa) is probably best know for the bath sponges that are made from the mature fruit. However, the immature fruit are good for eating, and are used in Asians, Chinese and Thai cuisines when they can be braised or cooked in curries.
To be harvested as a vegetable the fruit should be picked when they are 40 to 45cm long and 3 to 4 cm wide, when they have a soft puffy, texture.
The plants are heat lovers, so need to be grown in greenhouse or polytunnel. They are also vigorous growers so will fill whatever structure they are grown in. Seed should be sown in May into modules, and transplanted out in June. They need support for the vines to grow upwards.
If left on the plant the fruit of Luffa Longa will continue growing, reaching a mature size of up to a metre long. At this point they are inedible as they have the inner network of tough fibres that makes them good sponges.
To make a sponge bath the fruit must be allowed to mature fully on the plant. If there is enough growing time the fruit will dry out and turn brown naturally on the vine. Unfortunately, in the UK with our short summers it is highly possible the fruit will still be green in the late autumn. If this is the case the flesh and skin have to be “retted”, i.e. soaked in water to rot the flesh. The easiest way to do this is to keep them submerged in a trough or bucket of water – the fruit are so long they will have to be bent or cut in half, and as they float they will need to be weighted down. It takes about 1 to 2 weeks for the flesh to rot sufficiently for it to come off easily. Once a luffa is fully retted simply slip the skin off to reveal the fibrous sponge inside. Allow the sponge to dry, shake the seeds out, and you have your bath luffa! If you want a pure white bath sponge a few minutes soaking in dilute bleach will do the job. They make wonderful Christmas presents.
Please note: The seed needs a temperature of 27˚C to germinate, even then they are slow to emerge and come up erratically (so be patient).
Approximate number of seeds per pack: 8