Luffa is an interesting plant to grow in the home garden if you have a pergola or some structure for it to ramble over. If the fruit is picked small it can be delicious eaten like cucumber in salads or cooked in a stir fry and if left to mature can give a good crop of useful luffa for the bathroom and a great scourers for the kitchen.
Its beautiful yellow flowers and lush leaves make it a lovely screening plant that attracts the bees to the garden.
Growth habits and planting needs
Luffa love a moist, fertile, freely draining soil, full sun and a sturdy support for their tendrils to grip.
In Sydney, a temperate zone, it is sown in September and planted out in October, November and December.
The soil needs to be warm and at least 22º C for germination. Wait until the soil is warm enough or start off the seeds in the warmth of a greenhouse.
Select a site that has full sun as the plant prefers a long hot growing season. Sydney has excellent conditions for growing Luffa.
Make sure that you have a good supporting structure with wire to support the vine growth over the season. The structure will need to be strong. A chain link fence is ideal. Luffa can be grown over a pergola as the leaves will get sun and the gourds hang down to mature. If you are growing them to eat perhaps growing on a fence will allow continuous harvesting more easily and to encourage more fruiting. The plant uses tendrils to hold on as it grows and while young the plant can be encouraged to grow over the space you have provided.
Luffa prefer slightly acidic soil with a pH of 6.0 – 6.8
Dig over the planting site to a good tilth and dig in well rotted compost or other organic matter to enrich the soil to a depth of 15 to 20 cm. Limit fetilizers as this will encourage leaf growth at the expense of gourd development.
Create a mound to plant the seeds into.
Scarify the seed by rubbing over with sand paper. Then soak the seed for 24 hours. Plant 2-3 seeds in each mound, sowing the seeds 1.5 – 2.00 cm deep. Water in well.
The seeds will germinate in about 14 days.
When two true leaves have formed select the strongest seedling and pinch out or replant the others. Keep well watered until the gourds develop.
Mulch well around the plant but away from the stem to prevent evaporation and conserve water.
Pinch out the early lower laterals to encourage a strong vine and when the vines have reached the top of their support, pinch out the tips to encourage growth on the vine.
The male flowers form first before the female flowers so remove the early flowers to encourage the vine to grow and become more sturdy before fruiting. This will improve the quality of the gourds that grow.
The male flowers form clusters which flower one at a time on a thin stem. The female flower forms on an individual and thicker stem.
When pollinated the luffa gourd forms at the base of the female flowers much like a cucumber does.
A healthy vine growing in rich soil will give a good crop of gourds over the growing season.
If you want to eat the luffa, harvest when the soft gourd reaches about 12-15 cnm long. They will be still tender to cook. Picking often will encourage further fruiting.
Luffa are ready to harvest when the gourd changes from green to brown and the seeds rattle in the pod. From germination to maturity takes about 11-12 weeks. The skin is loose against the gourd and comes away easily. At this stage the inner luffa is a lighter colour. If left to completely dry out the inner luffa will become darker.
Use a secateurs to remove the gourds from the vine to avoid damaging a still productive plant.
Remove the cap at the end and shake out the seeds by tapping the gourd. Then peel away the outer skin. If left to dry out like the one in the photo the skin will shatter away and the luffa will be slightly darker. If you harvest the gourd when it changes colour and the skin is still loose the inner luffa will be lighter in colour. Soaking the gourd in water will help make removal of the skin easier.
Wash the inner luffa out with the hose to remove any remaing seeds ofor skin from the outside and allow to dry completely. It will be ready to cut into pieces for use in the kitchen as scourers or be kept as long luffas for bathroom. Store in bags to keep dry and dust free.