Divisi
When to plant Onion in Rwamagana
Eastern Province, Rwanda
Onion is a cool-season vegetable you grow for its bulb — the swollen base of the leaves — but across sub-Saharan Africa it is most often grown as an irrigated hot dry-season crop, and it stands real heat (up to about 42 °C) as long as the water never stops.
| Measure | Rain-fed | With irrigation |
|---|---|---|
| Fit | Favourable | |
| When to plant | 2 Feb 2027 – 13 Mar 2027 opens in 18 weeks | 21 Jan 2026 – 1 Jan 2027 |
| Expected harvest | about 24.9 t/ha | about 37.3 t/ha |
| Harvest | From 3 May 2027 to 11 Jul 2027, depending on the planting date | |
| Ready to harvest | 90–120 days after planting | |
Rain-fed. These dates are worked out from each place's own rainfall, for a field watered by the season — with irrigation a window can open earlier, close later, or come round more than once a year. Check your own field under What grows, or get the Divisi app for a calendar dated to your farm.
If you only get one chance to plant, aim for around 28 Feb 2027. That is the point in the window where the rains are most reliably established.
This season's outlook for Rwamagana leans wet. Plant at the early end of the window, and make sure water can drain off the field — a wet year does more damage through waterlogging than through the rain itself.
Planting after 13 Mar 2027 leaves the crop short of season: it runs into the dry months before it has finished filling.
What decides this in Rwamagana
| Rain and temperature | 96% |
|---|---|
| The soil | 76% |
| The lie of the land | 60% |
For onion in Rwamagana, the lie of the land is the tightest of the three at 60%. You cannot flatten it, but you can farm it: plant along the contour rather than up and down, ridge or tie ridges to hold water on the slope, and expect shallower rooting than the crop would manage on flat ground.
The 2026/27 season in Rwamagana
| Rainy seasons | One each year — one chance to plant, so timing carries it |
|---|---|
| When the rains are expected | September 2026 to June 2027 |
| Rain in a typical year | About 763 mm |
| This season's rain | Leaning wet — January, February, November and December look heavier than usual. Make sure water can drain off the field; a wet year does more damage through waterlogging and disease than through the rain itself. |
| This season's heat | Hotter than usual — about +1.2 °C over the growing months. Heat makes the same rain do less, so a dry spell bites sooner: do not plant late, and shade or mulch what you can. |
| What that supports | enough rain for a long crop, or two in a year, warm all year, so nothing but rain ends the season |
| Ground this covers | 3 kinds of ground. The season below is the largest that farms — about 48% of this area. |
| 48% | enough rain for a long crop, or two in a year; warm all year, so nothing but rain ends the season 276 growing days · about 770 mm · September to June |
|---|---|
| 44% | enough rain for a long crop, or two in a year; warm all year, so nothing but rain ends the season 280 growing days · about 800 mm · September to June |
| 6% | enough rain for one full main crop; warm all year, so nothing but rain ends the season 268 growing days · about 760 mm · September to June |
last updated 17 September 2026
What onion needs to grow here
| Soil it likes | well-drained sandy loam or loam soil |
|---|---|
| Soil sourness (pH) | Happiest between pH 6.0 and 7.0 |
| Spacing | 20 cm between rows, 7 cm between plants |
| Feed it most with | nitrogen, potassium and sulphur |
What it takes to grow onion in Rwamagana
| Planting material | About 500,000 plants per hectare |
|---|---|
| Nitrogen (N) | About 45 kg per hectare |
| Phosphate (P₂O₅) | About 9 kg per hectare |
| Potash (K₂O) | About 50 kg per hectare |
| In the shops | A basal compound at planting — Compound D, or an NPK blend — covers the phosphate and potash. A nitrogen top dressing — urea or AN — goes on once the crop is established. |
These are the nutrients a onion crop of that size carries off the field. What you actually apply depends on what your soil already holds — which is what a soil test, or the app's field records, tell you.
What to watch for
Grow Onion with a plan, not a guess
Everything above describes Rwamagana as a whole — your own soil, slope and rainfall will shift the dates. The Divisi app works them out for your field, and dates each job that follows.
Where to sell Onion nearby
Onion in nearby districts
This calendar moves
Planting windows shift with the forecast. Leave your email and we'll send what changed, and a note when planting time nears — a couple of emails a month at most.
Frequently asked questions
Will onion grow well in Rwamagana?
Rwamagana rates as favourable for onion.
When should I plant onion in Rwamagana?
Typically 2 Feb 2027 to 13 Mar 2027, forecast-adjusted.
Is this exact for my own field?
No — these are readings taken across Rwamagana, not on your field. Soil, slope and rainfall change from one farm to the next. Check your own location to see your own numbers.
