When to plant watermelons in Quebec City: 21 June – 19 July

In Quebec City, watermelon: sow for seedlings from 3 May to 21 June; plant into a greenhouse from 31 May to 19 July; plant out into open ground from 21 June to 19 July. For plants and seeds, the places nearby include Centre SMG (farm supply, 11 km); addresses and opening hours are below.

Watermelon in Quebec City: soil, season and weather

In Quebec City the soil, not frost, sets the date: the last frost is over around 5 May, but the top 7 cm of soil reaches 18 °C — the minimum on the watermelon card — only around 21 June, 47 days later.

Last spring frost	5 May
Top 7 cm of soil at 18 °C	21 June, 47 days after the last frost
Into an unheated greenhouse	31 May – 19 July; May outside: 6.7 °C at night, 17.9 °C by day; card 18–35 °C
First autumn frost	28 October, 129 days after the start
Days in the bed to the first harvest (card)	59
First harvest, if planted in this window	19 August – 16 September
Days left for picking	70
Daylight	15:21 on 24 May, 15:52 on 21 June
Watering outdoors when fruiting (card)	every 5 days; the driest month, September, has 11 rainy days

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

Watermelon in Quebec City: care after planting

Planted on 21 June: in the first weeks water every 5 days.

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

21 June — 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 Quebec City during the watermelon season

No month of the season averages above the watermelon card's 18–35 °C by day; the warmest, July, averages 25.4 °C. Months that stay below 18 °C even by day on average: October (13.3 °C). Nights average below 18 °C in every month of the season, from 5.4 °C to 16.2 °C.

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
June	22.6	12.6	144	13	15:51
July	25.4	16.2	161	16	15:31
August	24.2	15.3	144	15	14:15
September	20.2	11.1	101	11	12:37
October	13.3	5.4	128	12	10:58

ERA5 2016–2025, Open-Meteo

Watermelon in nearby cities

Around Quebec City, Montreal is 22 days earlier and Saguenay 11 days later.

City	Distance	Date	Difference
Trois-Rivières	114 km	31 May – 20 July	21 days earlier
Sherbrooke	165 km	18 June – 18 July	3 days earlier
Saguenay	180 km	2 July – 13 July	11 days later
Montreal	233 km	30 May – 23 July	22 days earlier
Bangor	288 km	25 June – 25 July	4 days later
Augusta	299 km	22 June – 25 July	1 day later

Where to buy watermelon plants and seeds near Quebec City

Buy plants ready to set out from 21 June to 19 July (from 31 May to 19 July for an unheated greenhouse); seed for raising your own is sown from 3 May to 21 June. Within 15 km of Quebec City OpenStreetMap lists 6 garden centres, 1 farm-supply shop and 3 markets (collected 20 October 2026).

Centre SMG — farm supply
Boulevard Wilfrid-Hamel 6325, L'Ancienne-Lorette · 11 km
Marché public de Sainte-Foy — market
Avenue Roland-Beaudin 920, G1V 4H8 Québec · May–Oct Mon–Sun 08:00–18:00 · 8 km · marchesaintefoy.com
The Artisans of the Quebec Cathedral — market
Mon–Sun 10:00–18:00 · 0 km · facebook.com
Pépinière Arboréal — garden centre
15 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.

Questions