When to plant watermelons in Le Havre: 11 June – 2 September

In Le Havre, watermelon: sow for seedlings from 23 April to 5 August; plant into a greenhouse from 21 May to 2 September; plant out into open ground from 11 June to 2 September. For plants and seeds, the places nearby include Au Jardin Fleuri (garden centre, 4 km) and Lethuillier SA (farm supply, 12 km); addresses and opening hours are below.

Watermelon in Le Havre: soil, season and weather

In Le Havre the soil, not frost, sets the date: the last frost is over around 14 February, but the top 7 cm of soil reaches 18 °C — the minimum on the watermelon card — only around 11 June, 117 days later.

Last spring frost	14 February
Top 7 cm of soil at 18 °C	11 June, 117 days after the last frost
Into an unheated greenhouse	21 May – 2 September; May outside: 10.2 °C at night, 17 °C by day; card 18–35 °C
First autumn frost	12 December, 184 days after the start
Days in the bed to the first harvest (card)	59
First harvest, if planted in this window	9 August – 31 October
Days left for picking	125
Daylight	15:17 on 14 May, 16:12 on 11 June
Watering outdoors when fruiting (card)	every 5 days; the driest month, July, has 13 rainy days

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

Watermelon in Le Havre: care after planting

Planted on 11 June: in the first weeks water every 5 days.

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

11 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 Le Havre 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: October (16.4 °C), November (11.8 °C) and December (9.5 °C). Nights average below 18 °C in every month of the season, from 5.5 °C to 15.7 °C.

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
June	20.4	13.6	69	12	16:15
July	22	15.5	62	13	15:53
August	22	15.7	66	12	14:28
September	20	13.9	93	13	12:40
October	16.4	11.2	115	15	10:51
November	11.8	7.7	119	17	9:08
December	9.5	5.5	121	16	8:11

ERA5 2016–2025, Open-Meteo

Watermelon in nearby cities

Around Le Havre, Le Mans is 11 days earlier and Brighton 39 days later.

City	Distance	Date	Difference
Caen	48 km	15 June – 26 August	4 days later
Rouen	72 km	16 June – 12 August	5 days later
Brighton	150 km	20 July – 22 August	39 days later
Amiens	164 km	12 June – 12 August	1 day later
Le Mans	166 km	31 May – 15 August	11 days earlier
Portsmouth	170 km	16 June – 22 August	5 days later

Where to buy watermelon plants and seeds near Le Havre

Buy plants ready to set out from 11 June to 2 September (from 21 May to 2 September for an unheated greenhouse); seed for raising your own is sown from 23 April to 5 August. Within 15 km of Le Havre OpenStreetMap lists 4 garden centres, 1 farm-supply shop, 1 plant nursery, 9 markets and 7 farm shops (collected 20 October 2026).

Au Jardin Fleuri — garden centre
Rue de Verdun 160, 76600 Le Havre · 4 km
Jardinerie Lecroq — garden centre
Route Départementale 6015 620, 76430 Epretot · 15 km
Lethuillier SA — farm supply
Rue du Carreau du Moulin 21, 76930 Cauville-sur-Mer · 12 km
Marché lundi, mercredi, vendredi — market
Avenue René Coty, Le Havre · Mon, Wed, Fri 07:30–13:30 · 1 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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