Yala and Maha are stored as named ranges. The Colombo sample also stores four rainfall seasons. Two sources that disagree are both kept. This guide does not average them into one calendar.
Open the planting calendar and choose a Sri Lanka zone. A month stays blank when no window places that crop there.
Colombo rainfall and cropping seasons
Low Country Wet Zone
First inter-monsoon · rainfall · March–April
Department of Meteorology Climate Seasons heading: March-April. A later paragraph on the same page says this inter-monsoon runs from March until mid-May. That second bound is not stored.
Official sourceUnverified — based on Climate of Sri Lanka, Department of Meteorology, accessed 2026-10-20: https://meteo.gov.lk/index.php?option=com_content&view=article&id=94&Itemid=310&lang=en; confirm for your microclimate.
Southwest monsoon · rainfall · May–September
Department of Meteorology Climate Seasons heading: May-September. A later paragraph on the same page says mid-May to October. That second bound is not stored. The page says the southwestern coastal belt receives 1000-1600 mm during this five-month period. It does not give that total for a Colombo station. Colombo is named for daytime humidity above 70 percent all year, almost 90 percent in June.
Official sourceUnverified — based on Climate of Sri Lanka, Department of Meteorology, accessed 2026-10-20: https://meteo.gov.lk/index.php?option=com_content&view=article&id=94&Itemid=310&lang=en; confirm for your microclimate.
Second inter-monsoon · rainfall · October–November
Department of Meteorology Climate Seasons heading: October-November.
Official sourceUnverified — based on Climate of Sri Lanka, Department of Meteorology, accessed 2026-10-20: https://meteo.gov.lk/index.php?option=com_content&view=article&id=94&Itemid=310&lang=en; confirm for your microclimate.
Northeast monsoon · rainfall · December–February
Department of Meteorology Climate Seasons heading: December-February. A later paragraph on the same page says December to March. That second bound is not stored.
Official sourceUnverified — based on Climate of Sri Lanka, Department of Meteorology, accessed 2026-10-20: https://meteo.gov.lk/index.php?option=com_content&view=article&id=94&Itemid=310&lang=en; confirm for your microclimate.
Yala (FAO) · agricultural · March–August
The FAO-hosted Department of Agriculture report calls Yala (southwest monsoon) the dry season from March to August. The National Drought Plan uses April-September. Both pairs are stored. They are not averaged.
Official sourceUnverified — based on 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; confirm for your microclimate.
Maha (FAO) · agricultural · September–February
The FAO-hosted Department of Agriculture report calls Maha (northeast monsoon) the wet season and the major cropping season from September to February. The National Drought Plan uses October-March. Both pairs are stored. They are not averaged.
Official sourceUnverified — based on 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; confirm for your microclimate.
Yala (National Drought Plan) · agricultural · April–September
National Drought Plan: Yala is April-September. April-June rainfall is described as the secondary cultivation season. The FAO-hosted report uses March-August. Not averaged.
Official sourceUnverified — based on 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; confirm for your microclimate.
Maha (National Drought Plan) · agricultural · October–March
National Drought Plan: Maha is October-March. October-December rainfall initiates the primary cultivation season. The FAO-hosted report uses September-February. Not averaged.
Official sourceUnverified — based on 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; confirm for your microclimate.
The same national seasons on the other zone samples
Each zone sample stores the national Yala and Maha pairs. A crop window is still separate from these season labels. Okra's wet-zone windows are one example: the official note records a year-round sentence and also stores separate Yala and Maha months. The calendar uses the stored months.
Mid Country
Yala (FAO) · agricultural · March–August
National cropping season for Sri Lanka. Stored on this zone sample because the source describes the island, not a rainfall total for the representative town. The FAO-hosted report calls Yala March to August. The National Drought Plan uses April–September. Both pairs are stored. They are not averaged.
Official sourceUnverified — based on 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; confirm for your microclimate.
Maha (FAO) · agricultural · September–February
National cropping season for Sri Lanka. Stored on this zone sample because the source describes the island, not a rainfall total for the representative town. The FAO-hosted report calls Maha September to February. The National Drought Plan uses October–March. Both pairs are stored. They are not averaged.
Official sourceUnverified — based on 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; confirm for your microclimate.
Yala (National Drought Plan) · agricultural · April–September
National cropping season for Sri Lanka. Stored on this zone sample because the source describes the island, not a rainfall total for the representative town. National Drought Plan: Yala is April–September. Not averaged with the FAO-hosted March–August pair.
Official sourceUnverified — based on 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; confirm for your microclimate.
Maha (National Drought Plan) · agricultural · October–March
National cropping season for Sri Lanka. Stored on this zone sample because the source describes the island, not a rainfall total for the representative town. National Drought Plan: Maha is October–March. Not averaged with the FAO-hosted September–February pair.
Official sourceUnverified — based on 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; confirm for your microclimate.
Up Country Wet Zone
Yala (FAO) · agricultural · March–August
National cropping season for Sri Lanka. Stored on this zone sample because the source describes the island, not a rainfall total for the representative town. The FAO-hosted report calls Yala March to August. The National Drought Plan uses April–September. Both pairs are stored. They are not averaged.
Official sourceUnverified — based on 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; confirm for your microclimate.
Maha (FAO) · agricultural · September–February
National cropping season for Sri Lanka. Stored on this zone sample because the source describes the island, not a rainfall total for the representative town. The FAO-hosted report calls Maha September to February. The National Drought Plan uses October–March. Both pairs are stored. They are not averaged.
Official sourceUnverified — based on 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; confirm for your microclimate.
Yala (National Drought Plan) · agricultural · April–September
National cropping season for Sri Lanka. Stored on this zone sample because the source describes the island, not a rainfall total for the representative town. National Drought Plan: Yala is April–September. Not averaged with the FAO-hosted March–August pair.
Official sourceUnverified — based on 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; confirm for your microclimate.
Maha (National Drought Plan) · agricultural · October–March
National cropping season for Sri Lanka. Stored on this zone sample because the source describes the island, not a rainfall total for the representative town. National Drought Plan: Maha is October–March. Not averaged with the FAO-hosted September–February pair.
Official sourceUnverified — based on 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; confirm for your microclimate.
Low Country Dry Zone
Yala (FAO) · agricultural · March–August
National cropping season for Sri Lanka. Stored on this zone sample because the source describes the island, not a rainfall total for the representative town. The FAO-hosted report calls Yala March to August. The National Drought Plan uses April–September. Both pairs are stored. They are not averaged.
Official sourceUnverified — based on 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; confirm for your microclimate.
Maha (FAO) · agricultural · September–February
National cropping season for Sri Lanka. Stored on this zone sample because the source describes the island, not a rainfall total for the representative town. The FAO-hosted report calls Maha September to February. The National Drought Plan uses October–March. Both pairs are stored. They are not averaged.
Official sourceUnverified — based on 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; confirm for your microclimate.
Yala (National Drought Plan) · agricultural · April–September
National cropping season for Sri Lanka. Stored on this zone sample because the source describes the island, not a rainfall total for the representative town. National Drought Plan: Yala is April–September. Not averaged with the FAO-hosted March–August pair.
Official sourceUnverified — based on 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; confirm for your microclimate.
Maha (National Drought Plan) · agricultural · October–March
National cropping season for Sri Lanka. Stored on this zone sample because the source describes the island, not a rainfall total for the representative town. National Drought Plan: Maha is October–March. Not averaged with the FAO-hosted September–February pair.
Official sourceUnverified — based on 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; confirm for your microclimate.
Official planting windows
Okra · Low Country Wet Zone
April–May · yala · direct sow
Climatic section: Yala, early April to early May. The opening sentence also says okra can be grown throughout the year. That sentence is not used to fill every month. The page excludes the up-country wet zone and does not name Colombo.
Official sourceUnverified — based on HORDI Crop - Okra, Department of Agriculture Sri Lanka, accessed 2026-10-20: https://doa.gov.lk/hordi-crop-okra/; confirm for your microclimate.
Okra · Low Country Wet Zone
September–October · maha · direct sow
Climatic section: Maha, early September to early October. Direct seeding. Harvest can continue over 50-100 days after planting.
Official sourceUnverified — based on HORDI Crop - Okra, Department of Agriculture Sri Lanka, accessed 2026-10-20: https://doa.gov.lk/hordi-crop-okra/; confirm for your microclimate.
No farmer field planting window is stored for this section.
Where to read a crop
The crop directory lists crops that have a sourced figure or a placed window. When to plant opens only those pairs.