When to plant cucumbers in Niigata: 20 May – 5 October

In Niigata, cucumber: sow for seedlings from 1 April to 7 September; plant into a greenhouse from 29 April to 5 October; plant out into open ground from 20 May to 5 October.

Cucumber in Niigata: soil, season and weather

In Niigata the soil, not frost, sets the date: the last frost is over around 8 March, but the top 7 cm of soil reaches 18 °C — the minimum on the cucumber card — only around 20 May, 73 days later.

Last spring frost	8 March
Top 7 cm of soil at 18 °C	20 May, 73 days after the last frost
Into an unheated greenhouse	29 April – 5 October; April outside: 7.8 °C at night, 15.2 °C by day; card 18–25 °C
First autumn frost	20 December, 214 days after the start
Days in the bed to the first harvest (card)	34
First harvest, if planted in this window	23 June – 8 November
Days left for picking	180
Daylight	13:26 on 22 April, 14:21 on 20 May
Watering outdoors when fruiting (card)	every 2 days; the driest month, May, has 13 rainy days

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

Cucumber in Niigata: care after planting

Planted on 20 May: in the first weeks water every 4 days.

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

27 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 Niigata during the cucumber season

No month of the season averages above the cucumber card's 18–35 °C by day; the warmest, August, averages 29.9 °C. Months that stay below 18 °C even by day on average: November (14.3 °C) and December (8.4 °C). Nights average below 18 °C in May, June and October–December (3.8–17.9 °C).

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
May	20.7	13	119	13	14:12
June	24.1	17.9	137	12	14:47
July	28.3	22.9	219	14	14:33
August	29.9	24.2	211	14	13:39
September	26.3	20.7	190	15	12:28
October	19.9	14.3	163	15	11:16
November	14.3	8.7	168	19	10:09
December	8.4	3.8	259	26	9:33

ERA5 2016–2025, Open-Meteo

Cucumber in nearby cities

Around Niigata, Tokyo is 22 days earlier and Sendai 18 days later.

City	Distance	Date	Difference
Sendai	165 km	7 June – 8 September	18 days later
Tokyo	255 km	28 April – 29 September	22 days earlier
Nagoya	360 km	6 May – 25 September	14 days earlier
Hamamatsu	376 km	2 May – 3 October	18 days earlier
Kyoto	436 km	14 May – 22 September	6 days earlier
Osaka	479 km	5 May – 2 October	15 days earlier

Where to buy cucumber plants and seeds near Niigata

Buy plants ready to set out from 20 May to 5 October (from 29 April to 5 October for an unheated greenhouse); seed for raising your own is sown from 1 April to 7 September. Within 15 km of Niigata OpenStreetMap lists 4 garden centres, 4 markets and 2 farm shops (collected 28 October 2026).

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