When to plant watermelons in Fargo: 31 May – 7 July

In Fargo, watermelon: sow for seedlings from 12 April to 9 June; plant into a greenhouse from 10 May to 7 July; plant out into open ground from 31 May to 7 July. For plants and seeds, the places nearby include Hildbrants Farmers Market (garden centre, 8 km); addresses and opening hours are below.

Watermelon in Fargo: soil, season and weather

In Fargo 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 – 7 July; May outside: 8.3 °C at night, 20.9 °C by day; card 18–35 °C
First autumn frost	16 October, 138 days after the start
Days in the bed to the first harvest (card)	59
First harvest, if planted in this window	29 July – 4 September
Days left for picking	79
Daylight	14:29 on 3 May, 15:35 on 31 May
Watering outdoors when fruiting (card)	every 5 days; the driest month, October, has 8 rainy days

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

Watermelon in Fargo: 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 Fargo during the watermelon season

No month of the season averages above the watermelon card's 18–35 °C by day; the warmest, July, averages 28.4 °C. Months that stay below 18 °C even by day on average: October (13.6 °C). Nights average below 18 °C in every month of the season, from 4.7 °C to 17.4 °C.

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
May	20.9	8.3	76	9	15:02
June	26.9	15.4	89	10	15:51
July	28.4	17.4	84	10	15:32
August	26.5	16.3	96	9	14:15
September	22.8	12.8	68	8	12:37
October	13.6	4.7	55	8	10:57

ERA5 2016–2025, Open-Meteo

Watermelon in nearby cities

Around Fargo, Sioux Falls is 7 days earlier and Duluth 28 days later.

City	Distance	Date	Difference
Grand Forks	118 km	5 June – 7 July	5 days later
Bismarck	303 km	31 May – 6 July	same day
Winnipeg	337 km	1 June – 3 July	1 day later
Minneapolis	345 km	28 May – 15 July	3 days earlier
Duluth	356 km	28 June – 19 July	28 days later
Sioux Falls	371 km	24 May – 12 July	7 days earlier

Where to buy watermelon plants and seeds near Fargo

Buy plants ready to set out from 31 May to 7 July (from 10 May to 7 July for an unheated greenhouse); seed for raising your own is sown from 12 April to 9 June. Within 15 km of Fargo OpenStreetMap lists 3 garden centres and 3 markets (collected 20 October 2026).

Hildbrants Farmers Market — garden centre
Main Avenue East 349, 58078 West Fargo · 8 km
Red River Market — market
Broadway North 210, 58102 Fargo · Jul 08–Oct 28 Sat 10:00–14:00 · 0 km · redriver.market
Moorhead Farmers Market — market
1st Avenue North 202, 56560 Moorhead · Jun–Sept: Tue 03:30–18:30; Jul 04 closed · 1 km · cityofmoorhead.com
Brewhalla — market
1st Avenue North 1702, 58103 Fargo · Mon–Sun 10:00–20:00 · 2 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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