Divisi
When to plant Irish potato in Kati
Kusini Unguja, United Republic of Tanzania
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 | 30 Jun 2027 – 9 Jul 2027 opens in 39 weeks | same |
| Expected harvest | about 15.3 t/ha | about 41.7 t/ha |
| Harvest | From 8 Sep 2027 to 16 Nov 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 | 50% | |
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 30 Jun 2027. That is the point in the window where the rains are most reliably established.
This season's rainfall outlook for Kati is close to normal, so these dates match the pattern the area usually follows.
Planting after 9 Jul 2027 leaves the crop short of season: it runs into the dry months before it has finished filling.
What decides this in Kati
| Rain and temperature | 96% |
|---|---|
| The soil | 76% |
| The lie of the land | 88% |
For irish potato in Kati, 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 Kati
| When the rains are expected | August 2026 to August 2026 |
|---|---|
| Rain in a typical year | About 1,631 mm |
| This season's rain | Rain close to usual — plan around about 1,631 mm falling roughly when it always does |
| 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 64% of this area. |
| 64% | enough rain for a long crop, or two in a year; warm all year, so nothing but rain ends the season 325 growing days · about 1,510 mm · August to August |
|---|---|
| 20% | enough rain for a long crop, or two in a year; warm all year, so nothing but rain ends the season 293 growing days · about 1,410 mm · October to July |
| 5% | enough rain for a long crop, or two in a year; warm all year, so nothing but rain ends the season 303 growing days · about 1,460 mm · October to August |
| 5% | enough rain for one full main crop; warm all year, so nothing but rain ends the season 267 growing days · about 1,220 mm · October to July |
last updated 16 September 2026
Limited water holds back about 55% 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 Kati
| Planting material | About 47,000 plants per hectare |
|---|---|
| Nitrogen (N) | About 50 kg per hectare |
| Phosphate (P₂O₅) | About 15 kg per hectare |
| Potash (K₂O) | About 89 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 Kati 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
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 Kati?
Kati rates as favourable for irish potato.
When should I plant irish potato in Kati?
Typically 30 Jun 2027 to 9 Jul 2027, forecast-adjusted.
Is this exact for my own field?
No — these are readings taken across Kati, not on your field. Soil, slope and rainfall change from one farm to the next. Check your own location to see your own numbers.
