Luffa: Grow Your Own Sponges

By Noris Ledesma, Curator of Tropical Fruit

Luffa also called “vegetable sponges” commonly used as a bath sponge. The luffa sponge is not unfamiliar in bath and kitchen. Once dried, the fruit full in fibers stiffen, holding together to form nature's perfect sponge, useful in gently exfoliating loose skin, meanwile young fruits can be cooked and eaten as squash or substituted for cucumber in salads.

What gardener can resist the chance to grow something new?

The species most adapted to South Florida are Luffa cylindrica and Luffa aegyptiaca. Both species are recognized by distinguished characteristics, oblong fruits, and beautiful robust vines making it an interesting addition to a vegetable or flower garden. Both species are grown commercially in China, Korea, Japan and Central America. The luffa sponge is generally sold commercially in bath, health, or drug stores, but it can also be homegrown in South Florida.

The plants are beautiful on their own and also look great climbing up in walls in a tropical landscape.

The seeds are easily sprouted,  using a mixture of sand and potting soil. Set the seedlings in a gallon container, and insert a wooden stake next to the plant so you can tie the plant to it for support. Protect your plant by putting it in an area that gets indirect sunlight and is away from cold drafts. 

The seedlings can be planted 6 to 8 feet apart with tall, sturdy trellis for support of the heavy fruit.  Luffas are extremely vigorous plant; vines reach lengths of 15 feet or more. The small seedlings grow slowly while the roots become established, and they prefer warm, dry climates. Luffa plants can be sensitive to frost. Cold protection must be provided for young plants by covering the entire plant. Take care not to let the blanket or box touch the leaves. They grow better in full sun, and plants will produce flowers in 2 months after planting.  Pruning is a must to keep the vine healthy. Prune off less vigorous growth and occasionally prune back vigorous growth to promote flowering. A granular fertilizer like 8-3-9 or similar formulation should be applied after one moth of planting.

Growing luffa is fun and rewarding. They make an excellent summer screen plant and the plants flower and set fruit all season. In appearance, a luffa looks like a cucumber. The attractive trailing vines of the plant will take over any available surface, yielding drooping green fruit in the summer. Luffa vines are often used to cover decaying fences or as privacy foliage, because they are dense and fast growing. When the vines are blooming, the bright yellow flowers attract many pollen gathering creatures including butterflies, ants, and bees.

Luffa is harvested for food in many parts of Asia. The immature fruit (under 6 inches long) can be prepared and eaten like cucumber, squash, or okra. In China, luffa is steamed, boiled, or stir-fried with garlic, onions, or dried prawns, and it's used as a cooling ingredient in spicy dishes. If growing for sponges, allow the fruits to turn from green to yellow on the vine. Fruits will lose quite a bit of moisture and become light. Luffas will dry on the vine, but in our climate conditions its better, cut them from the vine when they turn yellowish. Remove the tough outer skin and dry them in the sun. Cut off one end and shake out the seeds. 

There is really no excuse, for it takes up little space, it will grow well with a minimum of care. It would be difficult to name any other single plant that can be put to more uses than the lovely luffa vine!

Processing Luffa Sponge:

 

  • Allow the fruits to turn green brownish in color on the vine. South Florida it’s very humid. It may necessary to harvest while the fruits still display green pots, they can be picked and hung in a dry place until completely brown. 
  • Peel the skin of fruit to reveal the sponge-like fibers inside, and spray it clean with a high-pressure hose.
  • Soak the sponge in a weak bleach and water solution for five minutes, if a whiter sponge color is desired.
  • Cut the excess fibers from ends of sponge.
  • Dry sponges on a screen rack in a dry place with good air circulation.
  • Empty seeds into a large bowl to be saved for next season

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