When to plant watermelons in Saskatoon: 15 June – 27 June

In Saskatoon, watermelon: sow for seedlings from 27 April to 30 May; plant into a greenhouse from 25 May to 27 June; plant out into open ground from 15 June to 27 June. For plants and seeds, the places nearby include Hi-Way Greenhouse (garden centre, 3 km) and Early's Farm & Garden Centre Inc. (garden centre, 4 km); addresses and opening hours are below.

Watermelon in Saskatoon: soil, season and weather

In Saskatoon the soil, not frost, sets the date: the last frost is over around 15 May, but the top 7 cm of soil reaches 18 °C — the minimum on the watermelon card — only around 15 June, 31 days later. 113 days separate planting out (15 June) from the first autumn frost (6 October); the card's 59 days to the first harvest leave 54 for picking, so a start 7 weeks late would still fit.

Last spring frost	15 May
Top 7 cm of soil at 18 °C	15 June, 31 days after the last frost
Into an unheated greenhouse	25 May – 27 June; May outside: 5.8 °C at night, 19.2 °C by day; card 18–35 °C
First autumn frost	6 October, 113 days after the start
Days in the bed to the first harvest (card)	59
First harvest, if planted in this window	13 August – 25 August
Days left for picking	54
Daylight	15:50 on 18 May, 16:44 on 15 June
Watering outdoors when fruiting (card)	every 5 days; the driest month, October, has 5 rainy days

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

Watermelon in Saskatoon: care after planting

Planted on 15 June: in the first weeks water every 5 days.

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

15 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 Saskatoon during the watermelon season

No month of the season averages above the watermelon card's 18–35 °C by day; the warmest, July, averages 25.3 °C. Months that stay below 18 °C even by day on average: October (9.7 °C). Nights average below 18 °C in every month of the season, from 0.3 °C to 14 °C.

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
June	22.8	11.2	86	11	16:44
July	25.3	14	60	10	16:18
August	24.5	12.7	43	7	14:43
September	20.1	8.3	32	6	12:43
October	9.7	0.3	25	5	10:44

ERA5 2016–2025, Open-Meteo

Watermelon in nearby cities

Around Saskatoon, Winnipeg is 14 days earlier and Helena 18 days later.

City	Distance	Date	Difference
Regina	235 km	6 June – 27 June	9 days earlier
Edmonton	484 km	27 June – 27 June	12 days later
Calgary	525 km	18 June – 22 June	3 days later
Winnipeg	711 km	1 June – 3 July	14 days earlier
Billings	719 km	2 June – 5 July	13 days earlier
Helena	727 km	3 July – 5 August	18 days later

Where to buy watermelon plants and seeds near Saskatoon

Buy plants ready to set out from 15 June to 27 June (from 25 May to 27 June for an unheated greenhouse); seed for raising your own is sown from 27 April to 30 May. Within 15 km of Saskatoon OpenStreetMap lists 7 garden centres, 1 farm-supply shop, 1 plant nursery, 2 markets and 1 farm shop (collected 20 October 2026).

Wilson's Greenhouse — garden centre
Owen Manor 303, S7K 0P1 Saskatoon · Mon–Wed 10:00–18:00; Thu, Fri 10:00–20:00; Sat 10:00–18:00; Sun 11:00–17:00 · 8 km · wilsonslifestyle.ca
Early's Farm & Garden Centre Inc. — garden centre
Lorne Avenue 2615, S7J 0S5 Saskatoon · 4 km · earlysgarden.com
Early's — garden centre
51st Street East 502 · Mon–Sat 08:30–17:30 · 5 km · earlysgarden.com
Hi-Way Greenhouse — garden centre
11th Street West 2001 · 3 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