When to plant zucchini in Hiroshima: 26 May – 8 September

In Hiroshima, zucchini: sow for seedlings from 14 April to 18 August; plant into a greenhouse from 5 May to 8 September; plant out into open ground from 26 May to 8 September.

Zucchini in Hiroshima: soil, season and weather

In Hiroshima the soil, not frost, sets the date: the last frost is over around 9 April, but the top 7 cm of soil reaches 18 °C — the minimum on the zucchini card — only around 26 May, 47 days later.

Last spring frost	9 April
Top 7 cm of soil at 18 °C	26 May, 47 days after the last frost
First autumn frost	25 November, 183 days after the start
Days in the bed to the first harvest (card)	36
First harvest, if planted in this window	1 July – 14 October
Days left for picking	147
Daylight	13:40 on 5 May, 14:11 on 26 May
Watering outdoors when fruiting (card)	every 3 days; the driest month, November, has 6 rainy days

The same dates in Hiroshima hold for Cucumber, Bell Pepper, Eggplant, Pumpkin and Watermelon.

Zucchini in Hiroshima: care after planting

Planted on 26 May: in the first weeks water every 4 days.

Pests and diseases of zucchini to watch for:

Weather in Hiroshima during the zucchini season

About 1282 mm of rain falls in the season; November is the driest month (62 mm) and July the wettest (290 mm).

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
May	20.7	11	146	10	13:57
June	24	15.7	239	15	14:26
July	27.8	20.7	290	16	14:15
August	29.7	21.6	216	15	13:28
September	26	18	219	15	12:25
October	20.4	11.2	110	9	11:22
November	14.7	4.9	62	6	10:23

ERA5 2016–2025, Open-Meteo

Zucchini in nearby cities

All the nearest cities on our list plant zucchini earlier than Hiroshima; the closest date is in Kitakyushu, 11 days earlier.

City	Distance	Date	Difference
Okayama	138 km	14 May – 28 September	12 days earlier
Kitakyushu	155 km	from 15 May	11 days earlier
Fukuoka	209 km	5 May – 4 October	21 days earlier
Kumamoto	239 km	2 May – 16 September	24 days earlier
Osaka	281 km	5 May – 30 September	21 days earlier
Kyoto	311 km	14 May – 20 September	12 days earlier

Where to buy zucchini plants and seeds near Hiroshima

Buy plants ready to set out from 26 May to 8 September (from 5 May to 8 September for an unheated greenhouse); seed for raising your own is sown from 14 April to 18 August. Within 15 km of Hiroshima OpenStreetMap lists 2 garden centres, 2 farm-supply shops, 3 markets and 2 farm shops (collected 28 October 2026).

佐伯商店 — farm shop
3 km
無人市 — farm shop
3 km
グリーンセンター深川店 — garden centre
13 km
Pin Pon Pan — garden centre
4 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.

Questions