Divisi
When to plant Irish potato in Isiolo South
Isiolo, 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 | 1 Nov 2026 – 10 Nov 2026 opens in 5 weeks | 1 Jan 2026 – 30 Sep 2026 |
| Expected harvest | about 23.9 t/ha | same |
| Harvest | From 10 Jan 2027 to 20 Mar 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 meets its needs | 75% | |
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 Nov 2026. That is the point in the window where the rains are most reliably established.
No seasonal forecast reaches Isiolo South yet, so these dates follow the rains it usually gets rather than this year's.
Planting after 10 Nov 2026 leaves the crop short of season: it runs into the dry months before it has finished filling.
What decides this in Isiolo South
| Rain and temperature | 96% |
|---|---|
| The soil | 76% |
| The lie of the land | 88% |
For irish potato in Isiolo South, 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 2026 season in Isiolo South
| Rainy seasons | One each year — one chance to plant, so timing carries it |
|---|---|
| When the rains are expected | October 2026 to December 2026 |
| Rain in a typical year | About 346 mm |
| This season's rain | Leaning wet — 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 +0.8 °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 one short crop, and only if timed to it, warm all year, so nothing but rain ends the season |
| Ground this covers | 3 kinds of ground. The season below is the largest that farms — about 41% of this area. |
| 54% | too dry for rain-fed cropping without irrigation; warm all year, so nothing but rain ends the season no rain-fed season · about 280 mm |
|---|---|
| 41% | enough rain for one short crop, and only if timed to it; warm all year, so nothing but rain ends the season 98 growing days · about 380 mm · October to December |
| 3% | enough rain for one short crop, and only if timed to it; warm all year, so nothing but rain ends the season 140 growing days · about 530 mm · October to January |
last updated 30 September 2026
Limited water holds back about 25% 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 Isiolo South
| 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 Isiolo 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 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 Isiolo South?
Isiolo South rates as favourable for irish potato.
When should I plant irish potato in Isiolo South?
Typically 1 Nov 2026 to 10 Nov 2026, typical season.
Is this exact for my own field?
No — these are readings taken across Isiolo 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.
