Plant Pulse

When to plant Big onion in Low Country Dry Zone

When to plant Big onion in Low Country Dry Zone. Stored windows: Yala (April–May); Maha (December). Ranges from different sources are not averaged.

Unverified — based on Field Crops – Big onion – Sinhala, Department of Agriculture Sri Lanka, Sinhala page, accessed 2026-10-20: https://doa.gov.lk/field-crops-bigonion-si/; confirm for your microclimate.

Stored planting windows

  • Yala: April–May

    Transplant

    Farmer field experience. Using 85–100 stored days. Plant in Apr, first harvest about 85–100 days later (around July). Plant in May, first harvest around August. Calculated from the stored day count and the planting month. It is not a separate harvest calendar.

    Sinhala big-onion page: seedlings or dry bulbs, Yala from mid-April to mid-May. The grid marks April and May. Cultivation is mainly in the dry zone.

    Unverified — based on Field Crops – Big onion – Sinhala, Department of Agriculture Sri Lanka, accessed 2026-10-20: https://doa.gov.lk/field-crops-bigonion-si/; confirm for your microclimate.

  • Maha: December

    Transplant

    Farmer field experience. Using 85–100 stored days. Plant in Dec, first harvest about 85–100 days later (around March). Calculated from the stored day count and the planting month. It is not a separate harvest calendar.

    Sinhala big-onion page: if cultivated in Maha, during December.

    Unverified — based on Field Crops – Big onion – Sinhala, Department of Agriculture Sri Lanka, accessed 2026-10-20: https://doa.gov.lk/field-crops-bigonion-si/; confirm for your microclimate.

From farmer field experience

Based on hands-on growing experience from Sri Lankan farmers. Not yet verified against official sources.

  • March–May

    Transplant

    Farmer field experience. Using 85–100 stored days. Plant in Mar, first harvest about 85–100 days later (around June). Plant in May, first harvest around August. Calculated from the stored day count and the planting month. It is not a separate harvest calendar.

    Farmer field notenoted Oct 2026

    Low Country Dry Zone nursery, mid-March to May. The grid marks March, April, and May.

    Unverified — based on Farmer field experience, noted 2026-10-23; confirm for your microclimate.

  • May–July

    Transplant

    Farmer field experience. Using 85–100 stored days. Plant in May, first harvest about 85–100 days later (around August). Plant in Jul, first harvest around October. Calculated from the stored day count and the planting month. It is not a separate harvest calendar.

    Farmer field notenoted Oct 2026

    Low Country Dry Zone transplant, May–July, Yala.

    Unverified — based on Farmer field experience, noted 2026-10-23; confirm for your microclimate.

Season ranges

Two or more season ranges are stored. They are not joined. A month is marked only when it falls inside a stored range.

  • Yala is stored from more than one source, and the months do not match. Yala (FAO) is Mar–Aug. Yala (National Drought Plan) is Apr–Sep. Both ranges are shown. They are not averaged.
  • Maha is stored from more than one source, and the months do not match. Maha (FAO) is Sep–Feb. Maha (National Drought Plan) is Oct–Mar. Both ranges are shown. They are not averaged.

Agricultural seasons

  1. Yala (FAO): Mar–Aug (Agricultural)

    Improvement of plant nutrient management for better farmer livelihood, food security and environment in Sri Lanka, J.D.H. Wijewardena, Department of Agriculture, hosted by FAO, accessed 2026-10-20: https://www.fao.org/4/ag120e/AG120E12.htm

  2. Maha (FAO): Sep–Feb (Agricultural)

    Improvement of plant nutrient management for better farmer livelihood, food security and environment in Sri Lanka, J.D.H. Wijewardena, Department of Agriculture, hosted by FAO, accessed 2026-10-20: https://www.fao.org/4/ag120e/AG120E12.htm

  3. Yala (National Drought Plan): Apr–Sep (Agricultural)

    National Drought Plan for Sri Lanka, Ministry of Environment, September 2020, accessed 2026-10-20: https://www.unccd.int/sites/default/files/country_profile_documents/NDP%20of%20Sri%20Lanka-Final%20Report-Sept%202020.pdf

  4. Maha (National Drought Plan): Oct–Mar (Agricultural)

    National Drought Plan for Sri Lanka, Ministry of Environment, September 2020, accessed 2026-10-20: https://www.unccd.int/sites/default/files/country_profile_documents/NDP%20of%20Sri%20Lanka-Final%20Report-Sept%202020.pdf

Methodology

Where do these planting months come from?
Each range is a stored planting window for this crop and climate. A month that is not listed has no stored window. It is not a recommendation to skip planting.
Why can the same season appear more than once?
When two sources give different months for the same season, both ranges are listed. They are not averaged, and the gap between them is not filled in.
How are grower notes different from official windows?
Farmer field notes are labelled Farmer field experience, with the month they were noted. They are not official department windows, and they are not yet verified against official sources.

Big onion crop page · Planting calendar for Big onion in Low Country Dry Zone