When to plant tomatoes in Yellowknife: 22 June – 26 July

In Yellowknife, tomato: sow for seedlings from 10 April to 4 June; plant into a greenhouse from 1 June to 26 July; plant out into open ground from 22 June to 26 July. 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.

Tomato 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 15 °C — the minimum on the tomato card — only around 22 June, 30 days later. 104 days separate planting out (22 June) from the first autumn frost (4 October); the card's 70 days to the first harvest leave 34 for picking, so a start 4 weeks late would still fit.

Last spring frost	23 May
Top 7 cm of soil at 15 °C	22 June, 30 days after the last frost
Into an unheated greenhouse	1 June – 26 July; June outside: 8.6 °C at night, 18.7 °C by day; card 16–27 °C
First autumn frost	4 October, 104 days after the start
Days in the bed to the first harvest (card)	70
First harvest, if planted in this window	31 August – 4 October
Days left for picking	34
Daylight	16:24 on 1 May, 20:00 on 22 June
Watering outdoors when fruiting (card)	every 3 days; the driest month, October, has 8 rainy days

Tomato in Yellowknife: care after planting

Planted on 22 June: in the first weeks water every 4 days.

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

22 June — feed: balanced (NPK)
20 July — feed: nitrogen

Pests and diseases of tomato 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 tomato season

No month of the season averages above the tomato card's 16–27 °C by day; the warmest, July, averages 22 °C. Months that stay below 16 °C even by day on average: September (12.7 °C) and October (3 °C). Nights average below 16 °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

Tomato in nearby cities

Around Yellowknife, Kelowna is 34 days earlier and Juneau 11 days later.

City	Distance	Date	Difference
Edmonton	991 km	3 June – 16 June	19 days earlier
Whitehorse	1,107 km	29 June – 20 July	7 days later
Juneau	1,189 km	3 July – 28 July	11 days later
Saskatoon	1,235 km	30 May – 16 June	23 days earlier
Calgary	1,268 km	3 June – 11 June	19 days earlier
Kelowna	1,432 km	19 May – 11 July	34 days earlier

Where to buy tomato plants and seeds near Yellowknife

Buy plants ready to set out from 22 June to 26 July (from 1 June to 26 July for an unheated greenhouse); seed for raising your own is sown from 10 April to 4 June. 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.

Questions