Divisi
When to plant Bambara groundnut in Ambositra
Amoron I Mania, Madagascar
Bambara groundnut (Vigna subterranea) is one of Africa's own beans — a tough, low, bushy plant, often grown by the women of the household on the poorest, sandiest land where maize would fail.
| Fit | Moderate |
|---|---|
| When to plant | 18 Sep 2026 – 1 Jan 2027 open now |
| Expected harvest | about 0.7 t/ha |
| Harvest | From 17 Dec 2026 to 20 Jun 2027, depending on the planting date |
| Ready to harvest | 90–170 days after planting |
| Work it takes | 77–157 days per hectare, by hand |
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 8 Oct 2026. That is the point in the window where the rains are most reliably established.
This season's rainfall outlook for Ambositra is close to normal, so these dates match the pattern the area usually follows.
Planting after 1 Jan 2027 leaves the crop short of season: it runs into the dry months before it has finished filling.
What decides this in Ambositra
| Rain and temperature | 96% |
|---|---|
| The soil | 96% |
| The lie of the land | 30% |
For bambara groundnut in Ambositra, the lie of the land is the tightest of the three at 30%. 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 season in Ambositra
| When the rains are expected | September 2026 to September 2026 |
|---|---|
| Rain in a typical year | About 1,752 mm |
| This season's rain | Rain close to usual — plan around about 1,752 mm falling roughly when it always does |
| This season's heat | Hotter than usual — about +1.0 °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 | 4 kinds of ground. The season below is the largest that farms — about 47% of this area. |
| 47% | enough rain for a long crop, or two in a year; warm all year, so nothing but rain ends the season 362 growing days · about 1,610 mm · September to September |
|---|---|
| 20% | enough rain for one full main crop; warm all year, so nothing but rain ends the season 239 growing days · about 1,330 mm · October to June |
| 13% | enough rain for one full main crop; warm all year, so nothing but rain ends the season 249 growing days · about 1,310 mm · October to June |
| 11% | enough rain for a long crop, or two in a year; warm all year, so nothing but rain ends the season 308 growing days · about 1,390 mm · October to August |
last updated 17 September 2026
Sloping ground holds back about 65% of yield here.
What bambara groundnut needs to grow here
| Soil it likes | well-drained sand or sandy loam soil |
|---|---|
| Soil sourness (pH) | Happiest between pH 5.0 and 6.5 |
| Spacing | 40 cm between rows, 15 cm between plants |
| Feed it most with | phosphorus and calcium |
What it takes to grow bambara groundnut in Ambositra
| Planting material | About 125,000 plants per hectare |
|---|---|
| Nitrogen (N) | About 35 kg per hectare — the crop fixes most of this itself; inoculated seed matters more than a bag |
| Phosphate (P₂O₅) | About 7 kg per hectare |
| Potash (K₂O) | About 18 kg per hectare |
| In the shops | A basal compound at planting — Compound D, or an NPK blend — covers the phosphate and potash. Skip the nitrogen top dressing; inoculated seed does that job. |
| Hand work | 77–157 days per hectare, by hand |
These are the nutrients a bambara groundnut 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 Bambara groundnut with a plan, not a guess
Everything above describes Ambositra 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.
Bambara groundnut 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 bambara groundnut grow well in Ambositra?
Ambositra rates as moderate for bambara groundnut.
When should I plant bambara groundnut in Ambositra?
Typically 18 Sep 2026 to 1 Jan 2027, forecast-adjusted.
Is this exact for my own field?
No — these are readings taken across Ambositra, not on your field. Soil, slope and rainfall change from one farm to the next. Check your own location to see your own numbers.
