When to plant cucumbers in Okayama: 14 May – 30 September

In Okayama, cucumber: sow for seedlings from 26 March to 2 September; plant into a greenhouse from 23 April to 30 September; plant out into open ground from 14 May to 30 September. For plants and seeds, the places nearby include JA岡山はなやか南店 (farm shop, 5 km) and 早島町ふれあい青空市 (farm shop, 10 km); addresses and opening hours are below.

Cucumber in Okayama: soil, season and weather

In Okayama the soil, not frost, sets the date: the last frost is over around 20 March, but the top 7 cm of soil reaches 18 °C — the minimum on the cucumber card — only around 14 May, 55 days later.

Last spring frost	20 March
Top 7 cm of soil at 18 °C	14 May, 55 days after the last frost
Into an unheated greenhouse	23 April – 30 September; April outside: 9 °C at night, 19.1 °C by day; card 18–25 °C
First autumn frost	15 December, 215 days after the start
Days in the bed to the first harvest (card)	34
First harvest, if planted in this window	17 June – 3 November
Days left for picking	181
Daylight	13:04 on 16 April, 13:56 on 14 May
Watering outdoors when fruiting (card)	every 2 days; the driest month, December, has 5 rainy days

The same dates in Okayama hold for Bell Pepper, Eggplant, Zucchini, Pumpkin and Watermelon.

Cucumber in Okayama: care after planting

Planted on 14 May: in the first weeks water every 4 days.

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

21 May — feed: nitrogen

Pests and diseases of cucumber 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 Okayama during the cucumber season

No month of the season averages above the cucumber card's 18–35 °C by day; the warmest, August, averages 32.4 °C. Months that stay below 18 °C even by day on average: November (16.7 °C) and December (10.8 °C). Nights average below 18 °C in May and October–December (2.3–14.2 °C).

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
May	23.4	13.6	133	10	13:58
June	26.7	18.3	208	14	14:28
July	30.5	23.1	230	15	14:16
August	32.4	24.2	162	13	13:29
September	28.3	20.8	193	14	12:26
October	22.4	14.2	115	10	11:21
November	16.7	7.7	54	6	10:22
December	10.8	2.3	37	5	9:51

ERA5 2016–2025, Open-Meteo

Cucumber in nearby cities

Around Okayama, Osaka is 9 days earlier and Hiroshima 12 days later.

City	Distance	Date	Difference
Hiroshima	138 km	26 May – 10 September	12 days later
Osaka	145 km	5 May – 2 October	9 days earlier
Kyoto	174 km	14 May – 22 September	same day
Nagoya	278 km	6 May – 25 September	8 days earlier
Kitakyushu	292 km	from 15 May	1 day later
Fukuoka	345 km	5 May – 6 October	9 days earlier

Where to buy cucumber plants and seeds near Okayama

Buy plants ready to set out from 14 May to 30 September (from 23 April to 30 September for an unheated greenhouse); seed for raising your own is sown from 26 March to 2 September. Within 15 km of Okayama OpenStreetMap lists 8 garden centres, 5 farm-supply shops, 3 markets and 19 farm shops (collected 28 October 2026).

JA岡山はなやか南店 — farm shop
09:00–16:00 · 5 km · life.ja-group.jp
早島町ふれあい青空市 — farm shop
08:30–13:00; Sun closed · 10 km · jaokanishi.jp
あきちゃん農園 — farm shop
09:00–12:00 · 12 km · aki-ch.net
とれたて岡山産直マルシェinさいだいじ — farm shop
Mon–Sun 09:00–18:00 · 13 km · okafuru.com

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