When to plant Onion in Congo

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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.

Onion in Congo, rain-fed and with irrigation
Measure Rain-fed With irrigation
Fit Favourable
When to plant 20 Jul 2026 – 8 Oct 2026 open now 1 May 2027 – 30 Jun 2027
Expected harvest about 22.8 t/ha about 37.3 t/ha
Harvest From 18 Oct 2026 to 5 Feb 2027, depending on the planting date
Ready to harvest 90–120 days after planting
Rain meets its needs 96%

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 9 Aug 2026. That is the point in the window where the rains are most reliably established.

This season's rainfall outlook for Congo leans dry, so these dates sit later than the long-run average. Planting on the date you are used to risks germinating into a false start and having to replant.

Planting after 8 Oct 2026 leaves the crop short of season: it runs into the dry months before it has finished filling.

What decides this in Congo

Rain and temperature 96%
The soil 76%
The lie of the land 76%

For onion in Congo, the soil is the tightest of the three at 76%. This is the one you can actually move. Lime raises a sour soil, manure and compost lift what it holds, and both work within a season or two — money spent here changes the answer.

The 2025/26 season in Congo

Rainy seasonsOne each year — one chance to plant, so timing carries it
When the rains are expectedSeptember 2025 to July 2026
Rain in a typical yearAbout 1,390 mm in a typical farming district
Across its districtsFrom about 1,299 mm in the driest of 89 districts to about 1,894 mm in the wettest
This season's rainLeaning dry — January, September, October, November and December look short of rain. Plant at the early end of the window, favour quicker and more drought-tolerant crops, and keep moisture in the soil: mulch, and weed early.
This season's heatHotter 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 supportsenough rain for a long crop, or two in a year, warm all year, so nothing but rain ends the season
Ground this covers2 kinds of ground. The season below is one typical farming district's, not a figure for the whole of this area.
Agro-ecological zones covering this area
88% enough rain for a long crop, or two in a year; warm all year, so nothing but rain ends the season 322 growing days · about 1,410 mm · August to July
11% enough rain for a long crop, or two in a year; warm all year, so nothing but rain ends the season 296 growing days · about 1,400 mm · September to July

last updated 17 September 2026 · from all 89 areas within it

Frost and pest pressure hold back about 15% 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 Congo

Planting materialAbout 500,000 plants per hectare
Nitrogen (N)About 41 kg per hectare
Phosphate (P₂O₅)About 8 kg per hectare
Potash (K₂O)About 46 kg per hectare
In the shopsA 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

Pest/disease risk — manageableSoil pH outside the crop's rangeCorrect soil pH (lime)

Grow Onion with a plan, not a guess

Everything above describes Congo 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.

Or check your field first

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 Congo?

Congo rates as favourable for onion.

When should I plant onion in Congo?

Typically 20 Jul 2026 to 8 Oct 2026, forecast-adjusted.

Is this exact for my own field?

No — these are readings taken across Congo, not on your field. Soil, slope and rainfall change from one farm to the next. Check your own location to see your own numbers.

Also worth considering in Congo

Keep going

Timing is one question. What the crop needs at every stage, what attacks it and where to sell it are the others.