Greenly Garden

When to plant cucumbers in New Haven: 26 May – 28 August

In New Haven, cucumber: sow for seedlings from 7 April to 31 July; plant into a greenhouse from 5 May to 28 August; plant out into open ground from 26 May to 28 August.

Cucumber in New Haven: soil, season and weather

In New Haven the soil, not frost, sets the date: the last frost is over around 6 April, but the top 7 cm of soil reaches 18 °C — the minimum on the cucumber card — only around 26 May, 50 days later.

Last spring frost6 April
Top 7 cm of soil at 18 °C26 May, 50 days after the last frost
Into an unheated greenhouse5 May – 28 August; May outside: 10.5 °C at night, 19.4 °C by day; card 18–25 °C
First autumn frost12 November, 170 days after the start
Days in the bed to the first harvest (card)34
First harvest, if planted in this window29 June – 1 October
Days left for picking136
Daylight13:51 on 28 April, 14:49 on 26 May
Watering outdoors when fruiting (card)every 2 days; the driest month, June, has 10 rainy days

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

Cucumber in New Haven: care after planting

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

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

  • 2 June — 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 New Haven during the cucumber season

No month of the season averages above the cucumber card's 18–35 °C by day; the warmest, July, averages 28.2 °C. Months that stay below 18 °C even by day on average: November (11.5 °C). Nights average below 18 °C in May, June and September–November (3.5–15.9 °C).

MonthDay, °CNight, °CRain, mmRainy daysDaylight on the 15th
May19.410.51171314:29
June24.915.9811015:08
July28.220.11211214:53
August27.119.21031213:52
September23.615.81181012:31
October18.210.41251111:09
November11.53.58789:53

ERA5 2016–2025, Open-Meteo

Cucumber in nearby cities

Around New Haven, New York is 5 days earlier and Hartford 5 days later.

CityDistanceDateDifference
Hartford54 km31 May – 24 August5 days later
New York113 km21 May – 5 September5 days earlier
Providence138 km31 May – 24 August5 days later
Worcester (United States)141 km31 May – 24 August5 days later
Albany164 km30 May – 22 August4 days later
Boston193 km29 May – 29 August3 days later

Where to buy cucumber plants and seeds near New Haven

Buy plants ready to set out from 26 May to 28 August (from 5 May to 28 August for an unheated greenhouse); seed for raising your own is sown from 7 April to 31 July. Within 15 km of New Haven OpenStreetMap lists 5 garden centres, 1 plant nursery, 1 market and 3 farm shops (collected 28 October 2026).

Places: © OpenStreetMap contributors, ODbL.

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

When to plant cucumbers in New Haven?

In New Haven, cucumber: sow for seedlings from 7 April to 31 July; plant into a greenhouse from 5 May to 28 August; plant out into open ground from 26 May to 28 August.

When to sow cucumbers for seedlings in New Haven?

Sow for seedlings from 7 April to 31 July.

When is the last spring frost in New Haven?

Last spring frost around 6 April, first autumn frost around 12 November.

Other crops in New Haven, with their dates