When to plant watermelons in Rouen: 16 June – 12 August

In Rouen, watermelon: sow for seedlings from 28 April to 15 July; plant into a greenhouse from 26 May to 12 August; plant out into open ground from 16 June to 12 August. For plants and seeds, the places nearby include Le Producteur Local (farm shop, 4 km) and Le producteur local (farm shop, 4 km); addresses and opening hours are below.

Watermelon in Rouen: soil, season and weather

In Rouen the soil, not frost, sets the date: the last frost is over around 6 April, but the top 7 cm of soil reaches 18 °C — the minimum on the watermelon card — only around 16 June, 71 days later.

Last spring frost	6 April
Top 7 cm of soil at 18 °C	16 June, 71 days after the last frost
Into an unheated greenhouse	26 May – 12 August; May outside: 8.6 °C at night, 17.7 °C by day; card 18–35 °C
First autumn frost	21 November, 158 days after the start
Days in the bed to the first harvest (card)	59
First harvest, if planted in this window	14 August – 10 October
Days left for picking	99
Daylight	15:30 on 19 May, 16:15 on 16 June
Watering outdoors when fruiting (card)	every 5 days; the driest month, August, has 11 rainy days

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

Watermelon in Rouen: care after planting

Planted on 16 June: in the first weeks water every 5 days.

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

16 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 Rouen during the watermelon season

No month of the season averages above the watermelon card's 18–35 °C by day; the warmest, July, averages 23 °C. Months that stay below 18 °C even by day on average: October (16 °C) and November (10.7 °C). Nights average below 18 °C in every month of the season, from 5.2 °C to 13.9 °C.

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
June	21.5	12.2	72	12	16:15
July	23	13.8	57	10	15:53
August	23	13.9	56	11	14:28
September	20.2	11.9	68	12	12:40
October	16	9	87	14	10:51
November	10.7	5.2	90	14	9:08

ERA5 2016–2025, Open-Meteo

Watermelon in nearby cities

Around Rouen, Paris is 18 days earlier and Brighton 34 days later.

City	Distance	Date	Difference
Le Havre	72 km	11 June – 2 September	5 days earlier
Amiens	100 km	12 June – 12 August	4 days earlier
Caen	109 km	15 June – 26 August	1 day earlier
Paris	111 km	29 May – 11 August	18 days earlier
Le Mans	173 km	31 May – 15 August	16 days earlier
Brighton	178 km	20 July – 22 August	34 days later

Where to buy watermelon plants and seeds near Rouen

Buy plants ready to set out from 16 June to 12 August (from 26 May to 12 August for an unheated greenhouse); seed for raising your own is sown from 28 April to 15 July. Within 15 km of Rouen OpenStreetMap lists 8 garden centres, 18 markets and 15 farm shops (collected 27 October 2026).

Le Producteur Local — farm shop
Tue–Sat 09:30–19:30 · 4 km · leproducteurlocal.fr
Le producteur local — farm shop
Mon–Sat 09:30–19:00 · 4 km · montsaintaignan.leproducteurlocal.fr
La Ferme d'Isnel — farm shop
Route de Neufchâtel 100, 76230 Isneauville · Wed–Sat 09:30–12:30, Wed–Fri 13:30–19:00, Sat 13:30–18:00 · 6 km
Le Potager de Saint-Jean — farm shop
Aug 01–Oct 15 Mon 14:00–18:00; Aug 01–Oct 15 Wed–Sat 09:00–18:00; Oct 16–Jul 31 Mon, Thu closed; Oct 16–Jul 31 Wed, Fri, Sat 09:00–18:00 · 9 km · lepotagerdesaintjean.com

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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