How to Grow Luffa Seeds
Grow Guide #2286
Family: Cucurbitaceae
Binomial name: Luffa sp.
Life Cycle: Annual
This 'How to Grow' guide details everything a home gardener needs to know to plant, grow and care for Luffa (Luffa sp.).
When to Sow Luffa Seeds
Luffa is a warm season crop. Use the table below to identify the best time of year to sow luffa seeds in your climate.
JAN | FEB | MAR | APR | MAY | JUN | JUL | AUG | SEP | OCT | NOV | DEC | |
---|---|---|---|---|---|---|---|---|---|---|---|---|
Cool | ||||||||||||
Temperate | ||||||||||||
Sub-Tropical | ||||||||||||
Tropical | ||||||||||||
Arid |
Preparation
Luffa plants are best grown in full sun. Choose a location that will receive at least 6 hours of full sun each day.
Luffa plants need a well drained soil enriched with plenty of organic matter. Prepare soil by weeding it thoroughly, digging it over to loosen it and adding aged animal manure or compost. Keep the area free of weeds until planting. Learn more about preparing soil for planting here.
How to Sow Luffa Seeds
Optional: Scarifying seeds prior to planting will improve the speed and success of germination. Scarification involves intentionally damaging the hard outer coating of the seeds to allow water to reach the seed's embryo. Use a sharp knife to make a shallow nick in each seed's shell, or gently wear away a section of the husk using fine sandpaper or a nail file. Read more about scarification here.
Luffa seeds can be sown directly into the garden OR seedlings can be raised in trays or other containers and transplanted to the garden once established.
Sow Direct
- Sow seeds directly in the garden 15mm deep and 50cm apart, with rows 75cm apart.
- Keep soil moist but never wet or dry.
- Seeds should germinate in around 14-21 days at a soil temperature of 25-30°C.
- Young seedlings will need protection from pests, pets and weather until they are established.
Raise Seedlings
- Fill trays, punnets or jiffy pots with a good quality seed-raising mix, or use soil starter pellets.
- Sow seeds 15mm deep.
- Keep soil moist but never wet or dry.
- Seeds should germinate in around 14-21 days at a soil temperature of 25-30°C.
- Transplant seedlings to the garden once they have their first true leaves and are large enough to handle (usually 5-10cm tall).
- Plant out, spacing plants 50cm apart, with rows 75cm apart.
Luffa is a tender crop that’s sensitive to frost. Do not transplant seedlings or sow seeds outside until all danger of frost has passed.
Tip: Seeds of this variety can be slow to germinate. Take note of the expected germination time, be patient and follow the recommended depth and temperature guidelines closely for the best chance of success.
Optional: In cool climates luffa seeds can be sown indoors 6 weeks before the last expected frost. Grow them in a warm position with plenty of natural light.
How to Grow Luffa
Luffa plants may need watering during the growing season. Water when the soil is dry about 5cm below the surface (test this by scratching away a little soil with your finger). Water deeply in the early morning or late afternoon. Avoid watering the leaves of plants to avoid fungal diseases. Learn more about watering here.
If soil was well prepared no extra fertiliser should be necessary. In poor soil or to give your plants an extra boost, application of a balanced fertiliser or one formulated for fruit and vegetables can be beneficial:
- Apply slow release fertiliser at the recommended rate when transplanting or when seedlings are 5-10cm tall.
- Apply liquid fertiliser at the recommended rate and frequency while plants are fruiting or flowering.
Vines can sprawl along the ground or be grown up a strong trellis. If growing on the ground, allow at least 2 square metres per plant. If growing on a trellis, plants will attach themselves using their tendrils but extra support can be provided by tying plants gently using twine or plant ties. Make sure you have the support in place when you sow seed or transplant seedlings to avoid disturbing the plant’s roots later.
How to Harvest Luffa
Luffa should be ready to harvest in approximately 100-180 days.
Fruit is ready to harvest when the skin is glossy and the fruit is large enough to eat. Harvest fruit when tender and young as older fruit can become unpalatable. Harvest fruit by cutting it from the vine or bush, leaving a small amount of stem attached. For short term storage, harvested fruit can be kept in the fridge. For long term storage, fruit can be frozen, canned or pickled.
To use the fruit as sponges, leave fruit on the vine until it is fully ripe. The fruit will dry and turn brown. Peel off the skin and shake out the seeds.
Common Problems when Growing Luffa
Like all plants, luffa is susceptible to some pests, diseases and other problems. Below is a list of the most common problems gardeners encounter when growing luffa plants:
- Aphids are small (2-4mm long) sap-sucking insects that congregate on the new shoots or the undersides of leaves. They can cause leaves to wilt or become discoloured, and also excrete honeydew which can attract ants and other insect pests. To manage aphids, remove them by spraying with a garden hose, apply a soap or alcohol spray, or encourage predatory insects to your garden. Read more about aphids here.
- Not setting fruit is a problem caused by lack of pollination. Flowers may fall off the plant or small fruit may form but then shrivel and rot. Wait until the plant is producing both male and female flowers. Use a paintbrush to transfer pollen from the male flowers to the female ones. Learn more about hand pollination here..
- Possums, birds and other animals can ruin a large percentage of your harvest overnight. Physically exclude pests by using netting or cages, or try spraying plants with a pungent homemade spray made from garlic, fish oil or mustard.
- Powdery mildew is caused by fungal spores reproducing on the leaves of plants. First showing as white spots on leaves, affected areas can spread quickly to cover the entire leaf surface. While rarely fatal, powdery mildew can reduce yields. Water plants at soil level (not on leaves) to prevent spreading spores, allow good air flow between plants, remove affected leaves and if necessary spray with an appropriate fungicide or homemade spray. Read more here about powdery mildew here.