When to plant watermelons in Kitchener: 31 May – 17 July

In Kitchener, watermelon: sow for seedlings from 12 April to 19 June; plant into a greenhouse from 10 May to 17 July; plant out into open ground from 31 May to 17 July. For plants and seeds, the places nearby include Warren Greenhouses (garden centre, 2 km) and L&L Market (garden centre, 4 km); addresses and opening hours are below.

Watermelon in Kitchener: soil, season and weather

In Kitchener the soil, not frost, sets the date: the last frost is over around 30 April, but the top 7 cm of soil reaches 18 °C — the minimum on the watermelon card — only around 31 May, 31 days later.

Last spring frost	30 April
Top 7 cm of soil at 18 °C	31 May, 31 days after the last frost
Into an unheated greenhouse	10 May – 17 July; May outside: 7.8 °C at night, 19 °C by day; card 18–35 °C
First autumn frost	26 October, 148 days after the start
Days in the bed to the first harvest (card)	59
First harvest, if planted in this window	29 July – 14 September
Days left for picking	89
Daylight	14:12 on 3 May, 15:09 on 31 May
Watering outdoors when fruiting (card)	every 5 days; the driest month, September, has 9 rainy days

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

Watermelon in Kitchener: care after planting

Planted on 31 May: in the first weeks water every 5 days.

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

31 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 Kitchener during the watermelon season

No month of the season averages above the watermelon card's 18–35 °C by day; the warmest, July, averages 26.8 °C. Months that stay below 18 °C even by day on average: October (15 °C). Nights average below 18 °C in every month of the season, from 6.7 °C to 16.3 °C.

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
May	19	7.8	80	12	14:41
June	24.4	13.6	97	11	15:24
July	26.8	16.3	79	12	15:07
August	25.3	15.7	80	11	14:00
September	22.1	12.5	67	9	12:33
October	15	6.7	84	12	11:05

ERA5 2016–2025, Open-Meteo

Watermelon in nearby cities

Around Kitchener, Cleveland is 3 days earlier and Hamilton 1 day later.

City	Distance	Date	Difference
Hamilton	57 km	1 June – 29 July	1 day later
London (Canada)	77 km	29 May – 29 July	2 days earlier
Toronto	94 km	29 May – 21 July	2 days earlier
Buffalo	145 km	29 May – 1 August	2 days earlier
Erie	149 km	30 May – 10 August	1 day earlier
Cleveland	236 km	28 May – 12 August	3 days earlier

Where to buy watermelon plants and seeds near Kitchener

Buy plants ready to set out from 31 May to 17 July (from 10 May to 17 July for an unheated greenhouse); seed for raising your own is sown from 12 April to 19 June. Within 15 km of Kitchener OpenStreetMap lists 13 garden centres, 1 farm-supply shop, 4 markets and 5 farm shops (collected 20 October 2026).

L&L Market — garden centre
Lancaster Street West 101 · Mon–Sat 08:00–19:00; Sun 09:00–18:00 · 4 km
Warren Greenhouses — garden centre
Strange Street 115 · 2 km
Kolb's Green Thumb Nursery — garden centre
Victoria Street North 1501 · 7 km
Artistic Landscaping — garden centre
Albert Street · 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.

Questions