Greenly Garden

When to plant zucchini in New Haven: 26 May – 26 August

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

Zucchini 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 zucchini 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
First autumn frost12 November, 170 days after the start
Days in the bed to the first harvest (card)36
First harvest, if planted in this window1 July – 1 October
Days left for picking134
Daylight14:08 on 5 May, 14:49 on 26 May
Watering outdoors when fruiting (card)every 3 days; the driest month, June, has 10 rainy days

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

Zucchini in New Haven: 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 New Haven during the zucchini season

About 752 mm of rain falls in the season; June is the driest month (81 mm) and October the wettest (125 mm).

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

Zucchini in nearby cities

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

CityDistanceDateDifference
Hartford54 km31 May – 22 August5 days later
New York113 km21 May – 3 September5 days earlier
Providence138 km31 May – 22 August5 days later
Worcester (United States)141 km31 May – 22 August5 days later
Albany164 km30 May – 20 August4 days later
Boston193 km29 May – 27 August3 days later

Where to buy zucchini plants and seeds near New Haven

Buy plants ready to set out from 26 May to 26 August (from 5 May to 26 August for an unheated greenhouse); seed for raising your own is sown from 14 April to 5 August. 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 zucchini in New Haven?

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

When to sow zucchini for seedlings in New Haven?

Sow for seedlings from 14 April to 5 August.

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