Luffa/Loofah

Grow your own sponges with luffa gourds. Enjoy natural exfoliation and eco-friendly cleaning - say goodbye to plastic sponges and hello to a sustainable alternative! In addition, the young fruits are edible when small and taste like a cross between zucchini and cucumber.

20 organic seeds

KEY GROWING INFORMATION

Because of its long growing season and warm temperature requirements, it is best seeded directly in your garden. In cooler climates, start the seeds indoors at least 4-6 weeks before the last average frost date in your area. Plan for at least 150–200 frost-free days for harvest.

• In late spring, when the soil temperature has reached at least 70 degrees F, sow seeds in well-drained, tilled soil, three to four seeds per hole, and leave about six feet between the plants. Do not plant luffa in a location where you grew other members of the cucumber family (Cucurbitaceae) the year before.
• Cover the seeds with 1/2 to 3/4 inches of fine soil, lightly tamp them, and water them evenly.
• Seedlings typically emerge in 7 to 14 days, but germination may be slower.
• Thin to one seedling, keeping the most vigorous plant, when they are one to two inches high. If you don't start with a trellis but plan to drive posts or a cage system, keep the post away from the plant's tender root system.

LIGHT

Luffa needs at least six hours of full sun—the more the better.

SOIL

Luffa grows in any soil type but it prefers a pH range of 6.0 to 6.5. Excellent drainage, however, is key.

WATER

Keep the soil moist but not wet until the seedlings are established. After that, without sufficient rain, water the base of the plants with about 1 inch per week.

TEMPERATURE

Luffa needs warm to hot weather. In cool weather, its growth will slow down. High humidity is not an issue.

FERTILIZER

Add organic matter to the soil before planting, and add nitrogen-rich fertilizer two to three times during the growing season. 

The plants should have male and female flowers. A lack of either one is an indicator that the nutrient levels in the soil need adjustment. Soil high in nitrogen yields more male flowers; soil high in phosphorous produces more female flowers. 

POLLINATION

Crop and fruit production of luffa requires pollination. Male and female flowers look similar, but male flowers grow on a long stalk and are usually the first to appear. The flower blooms for one day and then falls off. The female flower grows on a short stalk (peduncle) but has an ovary in the shape of the fruit. The pollination of female flowers occurs primarily through bees.

If you notice a lack of bees, consider hand-pollination when the plants are flush with flowers.

HARVESTING

You can harvest luffa when it is still young and tender for eating it raw or cooked. The fruit grows fast, about an inch-and-a-half per day. Expect about four to six fruits per plant.

To grow luffa for sponges, let them grow about two feet long. Here's how to harvest them:

• Once the fruit has reached maturity, allow it to remain on the vine for several weeks to give it time to develop its tough inner fibers. Give it 150 to 200 warm, frost-free days from seed to harvest.
• Ideally, let it dry it on the vine before harvesting it. Cut the fruit from the vine with one to two inches of the stem attached; they should be tan and lightweight. Their skin should be thoroughly dried to a hard shell. When you shake a luffa, you should hear the seeds rattle inside, which indicates that the inside fibers have also dried and hardened. Luffa can also be harvested and processed while green if you have a shorter growing season with imminent frost in the forecast - it's just a little more work.
• To make sponges, immerse the luffa in warm water for about 20 minutes or until the skin is easily removed. Remove the seeds by shaking them loose, and remove any pulp.
• Once the luffa is gutted, soak it with a 10 percent bleach solution for one hour to kill bacteria. If you prefer not to use bleach, rinse it well under fresh water, shake it to remove excess water, and microwave it for one to three minutes until it's steaming hot. Allow it to dry in a warm, well-ventilated place before storing.

PRUNING

Trim young plants with sterilized pruners. To encourage vigorous branching, cut four stems back to the main stem.

Once the plant develops fruits, about two months before your first expected frost date, pinch away all the flowers and any small luffa on the vine. Pinching the most miniature fruits and flowers will direct the plant to put all its energy into growing the existing luffas on the vine into larger fruits.