When to plant tomatoes in Kumamoto: 2 April – 13 August

In Kumamoto, tomato: sow for seedlings from 19 January to 22 June; plant into a greenhouse from 12 March to 13 August; plant out into open ground from 2 April to 13 August. For plants and seeds, the places nearby include 合志物産館志来菜彩 (farm shop, 11 km) and ガーデン館 (garden centre, 12 km); addresses and opening hours are below.

Tomato in Kumamoto: soil, season and weather

In Kumamoto the soil, not frost, sets the date: the last frost is over around 18 March, but the top 7 cm of soil reaches 15 °C — the minimum on the tomato card — only around 2 April, 15 days later.

Last spring frost	18 March
Top 7 cm of soil at 15 °C	2 April, 15 days after the last frost
Into an unheated greenhouse	12 March – 13 August; March outside: 6.2 °C at night, 16.3 °C by day; card 16–27 °C
First autumn frost	3 December, 245 days after the start
Days in the bed to the first harvest (card)	70
First harvest, if planted in this window	11 June – 22 October
Days left for picking	175
Daylight	10:50 on 9 February, 12:33 on 2 April
Watering outdoors when fruiting (card)	every 3 days; the driest month, December, has 9 rainy days

Tomato in Kumamoto: care after planting

Planted on 2 April: in the first weeks water every 4 days.

Feeding, by the card’s schedule from that day:

2 April — feed: balanced (NPK)
30 April — feed: nitrogen

Pests and diseases of tomato to watch for:

Dates count from the first planting day of the window above; a later planting moves them by as many days.

Weather in Kumamoto during the tomato season

Days average above the tomato card's 16–27 °C in June–September (27.2–32.3 °C). Months that stay below 16 °C even by day on average: December (12.4 °C). Nights average below 16 °C in April, May and October–December (2.9–14.8 °C).

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
April	20.6	10.4	167	12	12:58
May	24.3	14.6	255	14	13:50
June	27.2	19.3	442	18	14:18
July	30.8	23.4	381	19	14:07
August	32.3	23.8	258	17	13:23
September	29.4	21.1	205	17	12:24
October	24.4	14.8	112	11	11:24
November	18.5	8.3	89	9	10:29
December	12.4	2.9	70	9	10:00

ERA5 2016–2025, Open-Meteo

Tomato in nearby cities

Around Kumamoto, Kagoshima is 2 days earlier and Hiroshima 33 days later.

City	Distance	Date	Difference
Fukuoka	92 km	7 April – 31 August	5 days later
Kitakyushu	121 km	from 14 April	12 days later
Kagoshima	134 km	31 March – 5 September	2 days earlier
Hiroshima	239 km	5 May – 5 August	33 days later
Busan	305 km	21 April – 2 August	19 days later
Ulsan	331 km	22 April – 27 July	20 days later

Where to buy tomato plants and seeds near Kumamoto

Buy plants ready to set out from 2 April to 13 August (from 12 March to 13 August for an unheated greenhouse); seed for raising your own is sown from 19 January to 22 June. Within 15 km of Kumamoto OpenStreetMap lists 3 garden centres, 5 markets and 2 farm shops (collected 28 October 2026).

ガーデン館 — garden centre
09:00–21:00 · 12 km · nishimuta.co.jp
フルーツの里　田原坂 — market
09:00–17:00 || "年末年始" · 10 km
植木青果市場 — market
08:30–22:00; Tue, Sat, public holidays -1 day closed · 13 km
合志物産館志来菜彩 — farm shop
09:00–19:00 · 11 km

Each window starts on the Greenly calendar date and ends on the last day that still leaves the crop’s days to harvest (from its card) before the average first autumn frost, plus six weeks of picking for crops harvested over weeks (tomatoes, peppers, aubergines, cucumbers, courgettes, pumpkins, watermelons, beans) — our rule; earlier in the window is safer.

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