When to plant watermelons in Windsor: 27 May – 29 July

In Windsor, watermelon: sow for seedlings from 8 April to 1 July; plant into a greenhouse from 6 May to 29 July; plant out into open ground from 27 May to 29 July. For plants and seeds, the places nearby include Key Foods (farm supply, 6 km) and Fairlane Gardens Landscape Supply (garden centre, 15 km); addresses and opening hours are below.

Watermelon in Windsor: soil, season and weather

In Windsor the soil, not frost, sets the date: the last frost is over around 24 April, but the top 7 cm of soil reaches 18 °C — the minimum on the watermelon card — only around 27 May, 33 days later.

Last spring frost	24 April
Top 7 cm of soil at 18 °C	27 May, 33 days after the last frost
Into an unheated greenhouse	6 May – 29 July; May outside: 10.6 °C at night, 20.7 °C by day; card 18–35 °C
First autumn frost	7 November, 164 days after the start
Days in the bed to the first harvest (card)	59
First harvest, if planted in this window	25 July – 26 September
Days left for picking	105
Daylight	13:57 on 29 April, 14:56 on 27 May
Watering outdoors when fruiting (card)	every 5 days; the driest month, November, has 9 rainy days

The same dates in Windsor hold for Cucumber, Bell Pepper, Eggplant, Zucchini and Pumpkin.

Watermelon in Windsor: care after planting

Planted on 27 May: in the first weeks water every 5 days.

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

27 May — feed: balanced (NPK)

Pests and diseases of watermelon 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 Windsor during the watermelon season

No month of the season averages above the watermelon card's 18–35 °C by day; the warmest, July, averages 28.6 °C. Months that stay below 18 °C even by day on average: October (17.2 °C) and November (9.1 °C). Nights average below 18 °C in May, June and September–November (2–16.5 °C).

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
May	20.7	10.6	90	13	14:34
June	26.6	16.5	90	11	15:15
July	28.6	19.3	92	12	14:59
August	27.2	18.4	91	11	13:56
September	24	15.5	72	9	12:32
October	17.2	9.2	90	12	11:07
November	9.1	2	60	9	9:49

ERA5 2016–2025, Open-Meteo

Watermelon in nearby cities

Around Windsor, Toledo (United States) is 3 days earlier and Ann Arbor 2 days later.

City	Distance	Date	Difference
Detroit	4 km	27 May – 29 July	same day
Ann Arbor	60 km	29 May – 27 July	2 days later
Toledo (United States)	84 km	24 May – 29 July	3 days earlier
Lansing	134 km	28 May – 24 July	1 day later
Cleveland	141 km	28 May – 12 August	1 day later
London (Canada)	165 km	29 May – 29 July	2 days later

Where to buy watermelon plants and seeds near Windsor

Buy plants ready to set out from 27 May to 29 July (from 6 May to 29 July for an unheated greenhouse); seed for raising your own is sown from 8 April to 1 July. Within 15 km of Windsor OpenStreetMap lists 3 garden centres, 1 farm-supply shop, 11 plant nurseries, 8 markets and 3 farm shops (collected 20 October 2026).

Meldrum Fresh Market Stand — farm shop
6 km
The Michigan Urban Farming Initiative — farm shop
9 km
Fairlane Gardens Landscape Supply — garden centre
Greenfield Road 4768, Dearborn · 15 km
Key Foods — farm supply
Russell Street 1352, 48207 Detroit · 6 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.

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