Divisi
When to plant Sweet potato in Keiyo South
Elgeyo-Marakwet, Kenya
Known here as kiazi kitamu · viazi vitamu
Sweet potato is a trailing vine you grow from vine cuttings (slips), not from seed and not by planting the root.
| Measure | Rain-fed | With irrigation |
|---|---|---|
| Fit | Favourable | |
| When to plant | 30 Mar 2027 – 21 May 2027 opens in 26 weeks | 1 Jan 2026 – 30 Sep 2026 |
| Expected harvest | about 20.1 t/ha | same |
| Harvest | From 28 Jun 2027 to 18 Oct 2027, depending on the planting date | |
| Ready to harvest | 90–150 days after planting | |
| Work it takes | 70–148 days per hectare, by hand | |
| 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 25 Apr 2027. That is the point in the window where the rains are most reliably established.
This season's outlook for Keiyo South 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 21 May 2027 leaves the crop short of season: it runs into the dry months before it has finished filling.
What decides this in Keiyo South
| Rain and temperature | 96% |
|---|---|
| The soil | 96% |
| The lie of the land | 60% |
For sweet potato in Keiyo South, 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 Keiyo South
| When the rains are expected | February 2026 to January 2027 |
|---|---|
| Rain in a typical year | About 1,351 mm |
| This season's rain | Leaning wet — January, February, 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 +1.1 °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 45% of this area. |
| 45% | enough rain for a long crop, or two in a year; warm all year, so nothing but rain ends the season 343 growing days · about 1,270 mm · February to January |
|---|---|
| 18% | enough rain for a long crop, or two in a year; warm all year, so nothing but rain ends the season 331 growing days · about 1,180 mm · February to January |
| 15% | enough rain for a long crop, or two in a year; warm all year, so nothing but rain ends the season 274 growing days · about 950 mm · March to December |
| 8% | enough rain for one full main crop; warm all year, so nothing but rain ends the season 267 growing days · about 880 mm · March to December |
last updated 30 September 2026
Sloping ground holds back about 20% of yield here.
What sweet potato needs to grow here
| Soil it likes | well-drained sandy, sandy loam or loam soil |
|---|---|
| Soil sourness (pH) | Happiest between pH 5.0 and 6.5 |
| Rain it needs | About 750–1,000 mm across the season |
| Spacing | 100 cm between rows, 30 cm between plants |
| Feed it most with | potassium and nitrogen |
What it takes to grow sweet potato in Keiyo South
| Planting material | About 33,000 plants per hectare |
|---|---|
| Nitrogen (N) | About 80 kg per hectare |
| Phosphate (P₂O₅) | About 30 kg per hectare |
| Potash (K₂O) | About 161 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. |
| Hand work | 70–148 days per hectare, by hand |
These are the nutrients a sweet potato 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 Sweet potato with a plan, not a guess
Everything above describes Keiyo South 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 Sweet potato nearby
Sweet potato 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 sweet potato grow well in Keiyo South?
Keiyo South rates as favourable for sweet potato.
When should I plant sweet potato in Keiyo South?
Typically 30 Mar 2027 to 21 May 2027, forecast-adjusted.
Is this exact for my own field?
No — these are readings taken across Keiyo South, not on your field. Soil, slope and rainfall change from one farm to the next. Check your own location to see your own numbers.
