Divisi
When to plant Irish potato in Tetu
Nyeri, Kenya
Known here as viazi mviringo · kiazi
The Irish potato (mbatatisi, ikirayi, viazi mviringo) is a cool-weather crop grown for the tubers that swell underground — it is not a grain, and it is not the same plant as sweet potato.
| Measure | Rain-fed | With irrigation |
|---|---|---|
| Fit | Favourable | |
| When to plant | 10 Feb 2027 – 22 Mar 2027 opens in 19 weeks | 21 Jan 2026 – 1 Jan 2027 |
| Expected harvest | about 23.9 t/ha | about 26.1 t/ha |
| Harvest | From 21 Apr 2027 to 30 Jul 2027, depending on the planting date | |
| Ready to harvest | 70–130 days after planting | |
| Work it takes | 110–185 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 2 Mar 2027. That is the point in the window where the rains are most reliably established.
This season's outlook for Tetu 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 22 Mar 2027 leaves the crop short of season: it runs into the dry months before it has finished filling.
What decides this in Tetu
| Rain and temperature | 96% |
|---|---|
| The soil | 96% |
| The lie of the land | 45% |
For irish potato in Tetu, 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 2025 season in Tetu
| When the rains are expected | December 2025 to December 2025 |
|---|---|
| Rain in a typical year | About 1,276 mm |
| This season's rain | Leaning wet — 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 +1.0 °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 36% of this area. |
| 36% | enough rain for a long crop, or two in a year; warm all year, so nothing but rain ends the season 365 growing days · about 1,190 mm · December to December |
|---|---|
| 28% | enough rain for a long crop, or two in a year; cool for part of the year, so frost sets the planting date 365 growing days · about 1,370 mm · January to December |
| 19% | enough rain for a long crop, or two in a year; warm all year, so nothing but rain ends the season 365 growing days · about 1,350 mm · January to December |
| 6% | enough rain for a long crop, or two in a year; cold for much of the year, with a short planting season 365 growing days · about 1,460 mm · January to December |
last updated 30 September 2026
Sloping ground holds back about 35% of yield here.
What irish potato needs to grow here
| Soil it likes | well-drained loam or sandy loam soil |
|---|---|
| Soil sourness (pH) | Happiest between pH 5.0 and 6.5 |
| Spacing | 75 cm between rows, 28 cm between plants |
| Feed it most with | potassium and magnesium |
What it takes to grow irish potato in Tetu
| Planting material | About 47,000 plants per hectare |
|---|---|
| Nitrogen (N) | About 79 kg per hectare |
| Phosphate (P₂O₅) | About 24 kg per hectare |
| Potash (K₂O) | About 139 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 | 110–185 days per hectare, by hand |
These are the nutrients a irish 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 Irish potato with a plan, not a guess
Everything above describes Tetu 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 Irish potato nearby
Irish 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 irish potato grow well in Tetu?
Tetu rates as favourable for irish potato.
When should I plant irish potato in Tetu?
Typically 10 Feb 2027 to 22 Mar 2027, forecast-adjusted.
Is this exact for my own field?
No — these are readings taken across Tetu, not on your field. Soil, slope and rainfall change from one farm to the next. Check your own location to see your own numbers.
