When to plant watermelons in Yellowknife: 30 June – 6 August

In Yellowknife, watermelon: sow for seedlings from 12 May to 9 July; plant into a greenhouse from 9 June to 6 August; plant out into open ground from 30 June to 6 August. For plants and seeds, the places nearby include Boreal Garden Centre (garden centre, 3 km) and Arctic Farmer Landscaping (garden centre, 4 km); addresses and opening hours are below.

Watermelon in Yellowknife: soil, season and weather

In Yellowknife the soil, not frost, sets the date: the last frost is over around 23 May, but the top 7 cm of soil reaches 18 °C — the minimum on the watermelon card — only around 30 June, 38 days later. 96 days separate planting out (30 June) from the first autumn frost (4 October); the card's 59 days to the first harvest leave 37 for picking, so a start 5 weeks late would still fit.

Last spring frost	23 May
Top 7 cm of soil at 18 °C	30 June, 38 days after the last frost
Into an unheated greenhouse	9 June – 6 August; June outside: 8.6 °C at night, 18.7 °C by day; card 18–35 °C
First autumn frost	4 October, 96 days after the start
Days in the bed to the first harvest (card)	59
First harvest, if planted in this window	28 August – 4 October
Days left for picking	37
Daylight	19:16 on 2 June, 19:51 on 30 June
Watering outdoors when fruiting (card)	every 5 days; the driest month, October, has 8 rainy days

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

Watermelon in Yellowknife: care after planting

Planted on 30 June: in the first weeks water every 5 days.

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

30 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 Yellowknife during the watermelon season

No month of the season averages above the watermelon card's 18–35 °C by day; the warmest, July, averages 22 °C. Months that stay below 18 °C even by day on average: September (12.7 °C) and October (3 °C). Nights average below 18 °C in every month of the season, from -1.3 °C to 13.3 °C.

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
June	18.7	8.6	35	6	19:55
July	22	13.3	43	8	18:59
August	19.7	12.1	46	9	16:08
September	12.7	6.5	33	7	13:03
October	3	-1.3	28	8	10:04

ERA5 2016–2025, Open-Meteo

Watermelon in nearby cities

Around Yellowknife, Kelowna is 28 days earlier and Whitehorse 9 days later.

City	Distance	Date	Difference
Edmonton	991 km	27 June – 27 June	3 days earlier
Whitehorse	1,107 km	9 July – 31 July	9 days later
Juneau	1,189 km	3 June – 27 June	27 days earlier
Saskatoon	1,235 km	15 June – 27 June	15 days earlier
Calgary	1,268 km	18 June – 22 June	12 days earlier
Kelowna	1,432 km	2 June – 22 July	28 days earlier

Where to buy watermelon plants and seeds near Yellowknife

Buy plants ready to set out from 30 June to 6 August (from 9 June to 6 August for an unheated greenhouse); seed for raising your own is sown from 12 May to 9 July. Within 15 km of Yellowknife OpenStreetMap lists 2 garden centres (collected 28 October 2026).

Boreal Garden Centre — garden centre
Drybones Drive 101 · 3 km
Arctic Farmer Landscaping — garden centre
Drybones Drive 106 · 4 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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