Divisi
When to plant Yam in Arsi
Oromia, Ethiopia
Yam is a climbing vine that grows one big food tuber underground over a long 7-11 month season.
| Measure | Rain-fed | With irrigation |
|---|---|---|
| Fit | Moderate | |
| When to plant | 2 Mar 2027 – 11 Apr 2027 opens in 22 weeks | 1 Jan 2027 – 30 Apr 2027 |
| Expected harvest | about 7.8 t/ha | same |
| Harvest | From 29 Aug 2027 to 6 Mar 2028, depending on the planting date | |
| Ready to harvest | 180–330 days after planting | |
| Rain meets its needs | 69% | |
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 1 Apr 2027. That is the point in the window where the rains are most reliably established.
This season's outlook for Arsi 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 11 Apr 2027 leaves the crop short of season: it runs into the dry months before it has finished filling.
What decides this in Arsi
| Rain and temperature | 96% |
|---|---|
| The soil | 96% |
| The lie of the land | 45% |
For yam in Arsi, the lie of the land is the tightest of the three at 45%. 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 2027 season in Arsi
| Rainy seasons | One each year — one chance to plant, so timing carries it |
|---|---|
| When the rains are expected | February 2027 to November 2027 |
| Rain in a typical year | About 1,095 mm |
| This season's rain | Leaning wet — February, October and November 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 +1.3 °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 32% of this area. |
| 32% | enough rain for a long crop, or two in a year; warm all year, so nothing but rain ends the season 285 growing days · about 1,090 mm · February to November |
|---|---|
| 26% | enough rain for one full main crop; warm all year, so nothing but rain ends the season 241 growing days · about 820 mm · March to November |
| 14% | enough rain for one full main crop; warm all year, so nothing but rain ends the season 219 growing days · about 700 mm · March to November |
| 5% | enough rain for one short crop, and only if timed to it; warm all year, so nothing but rain ends the season 176 growing days · about 730 mm · April to October |
last updated 16 September 2026
Limited water holds back about 55% of yield here.
What yam needs to grow here
| Soil it likes | well-drained sandy loam or loam soil |
|---|---|
| Soil sourness (pH) | Happiest between pH 5.5 and 7.0 |
| Spacing | 100 cm between rows, 100 cm between plants |
| Feed it most with | nitrogen and potassium |
What it takes to grow yam in Arsi
| Planting material | About 10,000 plants per hectare |
|---|---|
| Nitrogen (N) | About 29 kg per hectare |
| Phosphate (P₂O₅) | About 9 kg per hectare |
| Potash (K₂O) | About 45 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 yam 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 Yam with a plan, not a guess
Everything above describes Arsi 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.
Yam 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 yam grow well in Arsi?
Arsi rates as moderate for yam.
When should I plant yam in Arsi?
Typically 2 Mar 2027 to 11 Apr 2027, forecast-adjusted.
Is this exact for my own field?
No — these are readings taken across Arsi, not on your field. Soil, slope and rainfall change from one farm to the next. Check your own location to see your own numbers.
