Divisi
When to plant Irish potato in Toliary-I
Atsimo Andrefana, Madagascar
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.
| Fit | Favourable |
|---|---|
| When to plant | 21 May 2027 – 30 Jun 2027 opens in 33 weeks |
| Expected harvest | about 45.0 t/ha |
| Harvest | From 30 Jul 2027 to 7 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-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 21 May 2027. That is the point in the window where the rains are most reliably established.
This season's rainfall outlook for Toliary-I leans dry, so these dates sit later than the long-run average. Planting on the date you are used to risks germinating into a false start and having to replant.
Planting after 30 Jun 2027 leaves the crop short of season: it runs into the dry months before it has finished filling.
What decides this in Toliary-I
| Rain and temperature | 96% |
|---|---|
| The soil | 96% |
| The lie of the land | 96% |
For irish potato in Toliary-I, rain and temperature is the tightest of the three at 96%. This one is fixed. It is why the planting window above is where it is — hitting those dates is the whole of your control here.
The 2026/27 season in Toliary-I
| Rainy seasons | One each year — one chance to plant, so timing carries it |
|---|---|
| When the rains are expected | December 2026 to March 2027 |
| Rain in a typical year | About 562 mm |
| This season's rain | Leaning dry — January, February and December look short of rain. Plant at the early end of the window, favour quicker and more drought-tolerant crops, and keep moisture in the soil: mulch, and weed early. |
| This season's heat | Hotter than usual — about +1.6 °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 | 2 kinds of ground. The season below is the largest that farms — about 67% of this area. |
| 67% | 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 560 mm · December to March |
|---|---|
| 33% | enough rain for one short crop, and only if timed to it; warm all year, so nothing but rain ends the season 99 growing days · about 570 mm · December to March |
last updated 17 September 2026
Frost and pest pressure hold back about 15% 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 Toliary-I
| Planting material | About 47,000 plants per hectare |
|---|---|
| Nitrogen (N) | About 148 kg per hectare |
| Phosphate (P₂O₅) | About 45 kg per hectare |
| Potash (K₂O) | About 261 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 Toliary-I 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.
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 Toliary-I?
Toliary-I rates as favourable for irish potato.
When should I plant irish potato in Toliary-I?
Typically 21 May 2027 to 30 Jun 2027, forecast-adjusted.
Is this exact for my own field?
No — these are readings taken across Toliary-I, not on your field. Soil, slope and rainfall change from one farm to the next. Check your own location to see your own numbers.
