The Luffa or Loofah/Luffah are tropical and subtropical annual vines comprising the genus Luffa. The fruit of at least two species, Luffa acutangula and Luffa aegyptiaca, is grown to be harvested before maturity and eaten as a vegetable, popular in Asia and Africa.
The Luffa acutangula is commonly known as Ridged Gourd and is called “zika” in Assamese, si gua in Mandarin Chinese, Turai in Hindi, Gisoda in Gujarati, Beerakaya in Telugu, heeray kAyi in Kannada, wetakolu in Sinhala, mrop khia in Vietnamese language, patola in Tagalog, kabatiti in Ilocano, and gambas or oyong in Indonesia.
Loofah is a climbing vine related to gourds and cucumbers, and sometimes called the “dishrag vine,” a reference to the sponge-like qualities of the dried fruit. Six species are in the Luffa genus, and they are widely cultivated for food and sponge uses. The loofah is the only plant source of sponge, and it has been used in bathhouses and kitchens for centuries.
Loofah is harvested for food in many parts of Asia. All species of loofah are edible, but they must be consumed before they mature, or they will be too woody and fibrous to eat. Loofah is cooked before eating, and is sometimes seen on menus as “Chinese okra.” When allowed to mature and dry on the vine, loofah can be harvested as a sponge. The woody exterior skin is peeled away, and the seeds shaken out for reseeding. The loofah sponge can be sold whole, or chopped into smaller and more manageable portions. Loofah can also be compressed for shipping. The net of straw colored fibers will puff up again if the loofah is moistened.
The plant prefers deep well drained sandy loam soils, rich in organic matter with a pH ranging between 6.5 to 7.5. But it can also be grown on any good soil. The soil may be prepared well by adding organic matter or animal manure a few weeks before planting.
Once they get established, the plants are quite vigorous. They grow on vines that can reach well over 20 feet(6m) in length. A strong supporting trellis is a must. Chain link fence and lattice works great. The more support points the better. The fruits get very heavy. Luffa may survive in partial shade with some direct sunlight, but produce more in full sun. In a very hot dry climate they will need some watering as they tend to wilt if it gets too dry. Yearly rainfall here is typically 40 to 50 inches (102-127 cm). After the roots have developed, our vines don’t often need to be watered. If the leaves are wilting noticeably, then they may need additional water.
Planting can be propagated by direct seeding or transplanting. The seeds should be planted about 1-2 inch deep in the soil. Transplants can be done when 2-3 leaves develop and should be done in such a way as to avoid disturbance to the root system. The plants require a lot of space to grow and should be placed at a distance of 3 to 4 feet apart in rows. Place poles of any wood or bamboo 2m high as support and give wire or twine supports in rows. The plant requires only little water but regular watering is essential. Too much water during flowering and fruition is harmful to the plant.
The small seedlings grow very slowly while the roots become established. Once they are about 6 inches(15cm) tall the increase in growth rate is phenomenal. Flowering and fruition will occur around 6 weeks after sowing. The flowers bloom in an orderly progression, one at a time.
When the flowers get pollinated, slender cucumber-like vegetables appear. The fruits stay soft until the skin thickens. Then the fiber forms. The vines continue to grow and produce fruit until the sponges begin to mature. They can be harvested whenever they feel ready. The earlier ones can be picked while the vine is still growing. Typically they turn a yellow/brown color and become lighter in weight from drying out. Mature luffa pods can be any color from green to nearly black. Very small sponges can be mature and very large ones may not be ready. Size and color doesn’t matter much. The important thing is that they start to dry and lose weight. The more mature they are, the better the sponge fiber quality. Some smaller ones may mature more quickly, yielding a small soft sponge, good for washing delicate skin.
Problems and Care
Prune all side shoots on the main stem till about 1 metre from the ground. Less the number of fruits, more will be the size of the fruit.
Angled loofah is susceptible to many diseases and insect pests, such as nematodes, viruses, powdery mildew, leaf miners and spider mites. The major insect pests are fruit flies and aphids. Powdery mildew can be controlled by applying benomyl or sulfur dust. Fruit flies can be sprayed with protein hydrolysate mixed with insecticide. Leaf feeding beetles can be controlled by spraying with carbaryl of endosulfan. The insects can also be controlled by wrapping fruits with newspapers, when they are about a few centimeters long.
Harvesting and Preparing Luffa Sponges
Fruits are picked when they are dark green at the tender stage, before the angular ridges outside harden and fibrous network develops inside. Once mature, they become bitter and inedible. While cooking, ridges of the loofah can be peeled off thinly but the remaining portion with skin is edible.
When the sponges are ready for harvest they can be peeled. The skin loses green color and becomes looser when mature. The mature sponges tend to dry out and lose water weight. Generally, if the sponges have reached full growth they will be ready to peel. If they are green, the loofah may contain some fiber but be harder to peel. If it falls apart when you try to peel, it doesn’t have enough fiber and is not mature enough. It is always best to peel them as soon as possible if the vine dies. The longer the skin stays on, the darker the sponges will get. Peeling greener luffa is difficult but can be done if needed. Throwing the loofah hard at the ground is one trick. It’s good exercise for relieving your stress too. The bad ones will break apart, while the good ones will crack and loosen the skin. Letting the luffas freeze and thaw once on the vine also makes them easier to peel.
If they have matured they are usually easy to get open. Soaking in water will help the opening process. After peeling, high water pressure from a hose sprayer can remove much of any remaining green and brown coloration. Wash them with soap and water, lay out to dry, rotating occasionally, as the water settles in the lower side. Placing them in sun and wind outside dries them quickly. The sun tends to lighten them some. Hanging or placing the sponges on a screen works well for drying too.
If they are stained, a soak in some bleach and water will lighten them considerably. A wet harvest season tends to cause more rot and brown spots in the sponges. Getting all the seeds out can be a challenge, but the drier the sponges are, the easier the seeds will fall out. Save the best ones for next year. You can also cut open the sponges in any shape you want to remove seeds or make a loofah fiber mat.
Seeds should be allowed to dry and then stored in a cool place. Refrigerate or freeze in a sealed container for long term storage. We’ve had reports of seeds as old as ten years still germinating. If the seeds are allowed to get too hot and dry they become hard. Some hard seeds can still germinate but it may take a month to sprout.
Many Uses of Loofah
These natural spongy wonders of the vegetable world have many uses. They’ll make your skin squeaky clean or shine up your dirty dishes. The luffa flowers and fruits are soft and edible when young and can be cooked and eaten like squash or okra. Loofah has been an important food source in Asian cultures. When mature, the fruits become a tough mass of fiber that makes a great scrubbing sponge. The leaves and vines should not be eaten. When crushed, they produce a bitter compound and smell that seems to repel insects and animals. Some luffa varieties may produce fruits that are too bitter to eat. Peeling the skin off removes some of the bitterness. If it tastes bad, don’t eat it. Edible luffa can be found sometimes in markets with Asian style vegetables.
Luffa are most excellent in the bath or shower. The exfoliating action leaves your skin feeling the cleanest and tightest it could possibly be. Home soap makers can include slices of luffa in their creations to add an extra cleaning boost to their soaps. Shredded or powdered luffa can be added to soaps. A sponge on a handle or rope makes a great back scratcher. They can be cut into many shapes for scrubbing pads, bath mats, and other craft items. Cut the sponges lengthwise and remove the core to make sheets of sponge material.
Luffa sponges are great for washing items like plastic wares. You can use them for cleaning almost everything, including cars, boats, plastic buckets, and anything that needs scrubbed but can’t withstand steel wool. Non stick cookware is one example.
Powdered luffa has also been used in Chinese herbal medicine.
Care and Maintenance of Loofah Sponge
Luffa sponges will last a surprisingly long time if they are allowed to dry between uses, usually a few months. When they stay wet all the time they tend to deteriorate more.
Most commercial sponges are a light color from being bleached. Natural mature sponges can be any shade of brown to white in color. If you want to lighten sponges, then soak them in a weak chlorine bleach solution for about an hour or so. Commercial growers often use a hydrogen peroxide solution. Bleaching them for too long can significantly weaken the fibers. Bleached sponges look better for commerce. They are also cleaner and less likely to contain insects or other organic matter. Slightly green and/or stained ones can benefit from bleaching. Most sponges are fine in their natural state, without bleaching. Exposure to sunlight can also lighten the color some but not as dramatically as bleach. Leaving them in the sun for extended periods gives the loofa a rougher scratchier feel.
Like other sponges, loofah will collect bacteria if it is kept moist and warm, an environment common to bathrooms. For this reason, many people incorporating loofah into their beauty regimen prefer to use it as a dry exfoliating brush before bathing, or to grind it and use it in exfoliating scrubs. As a dry brush, loofah will gently remove the surface layer of dead skin, leaving the skin smooth and conditioned. Loofah can be used as a body sponge in the shower, but it should be allowed to dry out between uses. In the kitchen, loofah makes a great abrasive sponge for removing stubborn food particles from dishes and counter tops. Loofah is also gentle enough to use on delicate things like coated cookware which cannot withstand normal abrasives.
sources: wisegeek.com, luffa.info, en.wikipedia.org, webindia123.com, photo from www.parissoap.com