Divisi
When to plant Onion in Derrag
Medea, Algeria
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 | Moderate | |
| When to plant | 10 Dec 2026 – 30 Dec 2026 opens in 10 weeks | 21 Jan 2027 – 21 May 2027 |
| Expected harvest | 6.0–8.0 t/ha | about 28.5 t/ha |
| Harvest | From 10 Mar 2027 to 29 Apr 2027, depending on the planting date | |
| Ready to harvest | 90–120 days after planting | |
| Rain meets its needs | 40% | |
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 20 Dec 2026. That is the point in the window where the rains are most reliably established.
This season's rainfall outlook for Derrag is close to normal, so these dates match the pattern the area usually follows.
Planting after 30 Dec 2026 leaves the crop short of season: it runs into the dry months before it has finished filling.
What decides this in Derrag
| Rain and temperature | 88% |
|---|---|
| The soil | 76% |
| The lie of the land | 60% |
For onion in Derrag, 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 Derrag
| When the rains are expected | October 2026 to April 2027 |
|---|---|
| Rain in a typical year | About 494 mm |
| This season's rain | Rain close to usual — plan around about 494 mm falling roughly when it always does |
| This season's heat | Hotter than usual — about +1.4 °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, with a cool spell that slows winter growth |
| Ground this covers | 4 kinds of ground. The season below is the largest that farms — about 39% of this area. |
| 39% | enough rain for one full main crop; warm, with a cool spell that slows winter growth 200 growing days · about 490 mm · October to April |
|---|---|
| 35% | enough rain for one short crop, and only if timed to it; warm, with a cool spell that slows winter growth 167 growing days · about 410 mm · October to March |
| 13% | enough rain for one full main crop; cool for part of the year, so frost sets the planting date 195 growing days · about 550 mm · September to May |
| 9% | enough rain for one short crop, and only if timed to it; cool for part of the year, so frost sets the planting date 166 growing days · about 610 mm · February to May |
last updated 17 September 2026
Limited water holds back about 65% 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 Derrag
| Planting material | About 500,000 plants per hectare |
|---|---|
| Nitrogen (N) | About 13 kg per hectare |
| Phosphate (P₂O₅) | About 3 kg per hectare |
| Potash (K₂O) | About 14 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 Derrag 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.
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 Derrag?
Derrag rates as moderate for onion.
When should I plant onion in Derrag?
Typically 10 Dec 2026 to 30 Dec 2026, forecast-adjusted.
Is this exact for my own field?
No — these are readings taken across Derrag, not on your field. Soil, slope and rainfall change from one farm to the next. Check your own location to see your own numbers.
