Description

Watakolu is a cucurbitaceous vine that is commercially grown for its unripe fruits as a vegetable. Watakolu is related to cucumbers, squash, pumpkins, and melons. Its fruit slightly resembles a cucumber or zucchini with ridges, and can be steamed, stewed or curried. Raw watakolu tastes somewhere between cucumber and zucchini. Many fruits grow on a single vine. Mature fruits are used as natural cleaning sponges.

In Sri Lanka, three main varieties are cultivated in home gardens and commercial farms across different agro-ecological zones.


Planting requirements

Planting season:

Planting conditions:

Propagation Seeds
Planting method Soak the seeds in water for about 24 hours. Plant about 3-4 seeds per pit, fairly away from each other. Keep the seeds well watered. Before transplanting harrow the soil and break it finely. Mark pits to recommended spacing, 1.5m x 1.5m (between rows and between plants) . Make several deep drains to avoid excess water retention in field
Soil Well-draining, sandy loam soil with organic matter. Soil pH should be around 5.5-7.5 for optimal growth. Set up trellises about 2m high using strong poles spaced about 3m apart. Train vines vertically or horizontally on ropes or wire. Remove side vines/water sprouts from the main stem
Water Irrigate twice a day until seeds are germinated. After that, irrigation should be practiced according to soil moisture conditions
Light Requires full sunlight

Growing conditions:

Temperatures Thrives in hot weather. Temperatures between 25-30Β°C are ideal for growth
Soil Well-draining, sandy loam soil with organic matter. Maintain pH between 5.5-7.5
Water After germination, water according to soil moisture conditions. Avoid waterlogging
Pruning Use sharp, clean cutting tools for luffa pruning to prevent disease, trimming young plants to four stems and cutting them back to the main stem while pinching off the first male flowers to allow female flowers to develop fruit
Weed control Luffa has a shallow root system, so take care not to damage the roots of the vines when controlling weeds

Harvesting

Irrigate the evening before harvesting. Harvest around 14 days after flowering. Harvest with the stalk to avoid damaging the fruit. First harvesting can be done around 60-70 days after planting. 10-15 harvestings can be done over a period of 1Β½ – 2 months with 4-day intervals.


Curing

Avoid direct sunlight on harvested fruits. Pack in baskets to ensure good ventilation to prevent fruit damage. For sponge use, cure the fruits in the sun for about 3-5 days to harden them.


Storage

Store cured Watakolu sponges in a dry, well-ventilated area away from direct sunlight.


Protecting your plants

Pest control

Pest type:

Symptoms:

Control method:

Disease Control

Disease type:

Symptoms:

Management:

In General:


Sources

In addition to our General List of Sources (link), we used these specific references:

Luffa_Chinese-okra.jpeg
Image - Anna Frodesiak, Wikimedia Commons

Watakolu

Generic name: Chinese Okra, Sponge Gourd, Angled luffa, Ridge gourd
Sri Lankan name: Wetakolu (Sinhala) | PΔ«rkku (Tamil)
Scientific name: Luffa acutangula
Plant family: Cucurbitaceae
Edible parts: Fruit
Nutrition value: Rich in antioxidants, low in calories, and a significant source of vitamin A

Difficulty rating

Low country wet zone

Difficulty:

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Explanation: Watakolu can be cultivated throughout the year in the wet zone, including areas like Colombo, Galle, and Ratnapura.
Challenges/Adaptations:

  • Monitor and manage fungal diseases due to high humidity
  • Ensure proper drainage to prevent waterlogging

Low country dry zone

Difficulty:

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Explanation: Watakolu cultivation in the dry zone requires some irrigation management. This zone includes areas like Anuradhapura, Polonnaruwa, and Hambantota.
Challenges/Adaptations:

  • Implement efficient irrigation systems, especially during dry periods
  • Use mulching to conserve soil moisture
  • Provide shade during peak hours to prevent excessive heat stress

Mid country

Difficulty:

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Explanation: Watakolu cultivation in the mid country requires some water balancing, but is otherwise quite doable. This zone includes areas like Kandy, Matale, and Badulla.
Challenges/Adaptations:

  • Balance water requirements to avoid both drought and waterlogging
  • Monitor for pests and diseases regularly

Up country

Difficulty:

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Explanation: Watakolu cultivation in the upcountry is challenging due to cooler temperatures, which are less ideal for this heat-loving crop. This zone includes areas like Nuwara Eliya and parts of Badulla.
Challenges/Adaptations:

  • Select warmer, sheltered locations for cultivation
  • Use protective structures or greenhouses to maintain higher temperatures
  • Provide additional support for vines to protect against strong winds
  • Adjust planting times to coincide with warmer months

Companion plants

Companion plants aid growth by attracting beneficial insects, repelling pests, and providing support. They are part of a natural pest control system, maximising space and increasing crop productivity.

Non-companion plants

Non-companion plants are those that negatively affect each other’s growth when planted together, often due to competition for resources or chemical interference. Avoiding these pairings helps improve plant health and yields.