Divisi
When to plant Onion in Garsen
Tana River, Kenya
Known here as kitunguu
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 | 4 Oct 2026 – 24 Oct 2026 opens in 1 week | 1 May 2027 – 20 Jul 2027 |
| Expected harvest | about 19.6 t/ha | about 45.0 t/ha |
| Harvest | From 2 Jan 2027 to 21 Feb 2027, depending on the planting date | |
| Ready to harvest | 90–120 days after planting | |
| Rain meets its needs | 88% | |
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 14 Oct 2026. That is the point in the window where the rains are most reliably established.
This season's outlook for Garsen 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 24 Oct 2026 leaves the crop short of season: it runs into the dry months before it has finished filling.
What decides this in Garsen
| Rain and temperature | 88% |
|---|---|
| The soil | 96% |
| The lie of the land | 96% |
For onion in Garsen, rain and temperature is the tightest of the three at 88%. This one is fixed. It is why the planting window above is where it is — hitting those dates is the whole of your control here.
The 2026/27 season in Garsen
| Rainy seasons | Two each year — two chances to plant |
|---|---|
| When the rains are expected | October 2026 to January 2027 |
| Rain in a typical year | About 680 mm |
| This season's rain | Leaning wet — January, October, 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 +0.9 °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 one full main crop, warm all year, so nothing but rain ends the season |
| Ground this covers | 4 kinds of ground. The season below is the largest that farms — about 60% of this area. |
| 60% | enough rain for one full main crop; warm all year, so nothing but rain ends the season 203 growing days · about 720 mm · September to January |
|---|---|
| 19% | enough rain for one short crop, and only if timed to it; warm all year, so nothing but rain ends the season 147 growing days · about 580 mm · September to December |
| 14% | enough rain for one short crop, and only if timed to it; warm all year, so nothing but rain ends the season 171 growing days · about 620 mm · September to December |
| 3% | enough rain for one full main crop; warm all year, so nothing but rain ends the season 249 growing days · about 950 mm · March to December |
last updated 30 September 2026
Temperature holds back about 25% of yield here.
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 Garsen
| Planting material | About 500,000 plants per hectare |
|---|---|
| Nitrogen (N) | About 35 kg per hectare |
| Phosphate (P₂O₅) | About 7 kg per hectare |
| Potash (K₂O) | About 39 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 Garsen 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 Garsen?
Garsen rates as favourable for onion.
When should I plant onion in Garsen?
Typically 4 Oct 2026 to 24 Oct 2026, forecast-adjusted.
Is this exact for my own field?
No — these are readings taken across Garsen, not on your field. Soil, slope and rainfall change from one farm to the next. Check your own location to see your own numbers.
