When to plant watermelons in Luxembourg: 7 June – 9 August

In Luxembourg, watermelon: sow for seedlings from 19 April to 12 July; plant into a greenhouse from 17 May to 9 August; plant out into open ground from 7 June to 9 August.

Watermelon in Luxembourg: soil, season and weather

In Luxembourg the soil, not frost, sets the date: the last frost is over around 15 April, but the top 7 cm of soil reaches 18 °C — the minimum on the watermelon card — only around 7 June, 53 days later.

Last spring frost	15 April
Top 7 cm of soil at 18 °C	7 June, 53 days after the last frost
Into an unheated greenhouse	17 May – 9 August; May outside: 8.4 °C at night, 18.1 °C by day; card 18–35 °C
First autumn frost	18 November, 164 days after the start
Days in the bed to the first harvest (card)	59
First harvest, if planted in this window	5 August – 7 October
Days left for picking	105
Daylight	15:06 on 10 May, 16:09 on 7 June
Watering outdoors when fruiting (card)	every 5 days; the driest month, August, has 11 rainy days

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

Watermelon in Luxembourg: care after planting

Planted on 7 June: in the first weeks water every 5 days.

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

7 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 Luxembourg during the watermelon season

No month of the season averages above the watermelon card's 18–35 °C by day; the warmest, August, averages 24.2 °C. Months that stay below 18 °C even by day on average: October (15.2 °C) and November (8.9 °C). Nights average below 18 °C in every month of the season, from 3.1 °C to 14.2 °C.

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
June	22.9	12.9	69	12	16:17
July	24	13.9	65	10	15:54
August	24.2	14.2	53	11	14:29
September	20.4	10.9	74	11	12:40
October	15.2	7.6	85	13	10:51
November	8.9	3.1	78	13	9:07

ERA5 2016–2025, Open-Meteo

Watermelon in nearby cities

Around Luxembourg, Saarbrücken is 4 days earlier and Esch-sur-Alzette 8 days later.

City	Distance	Date	Difference
Esch-sur-Alzette	16 km	15 June – 9 August	8 days later
Ettelbruck	27 km	6 June – 6 August	1 day earlier
Metz	55 km	4 June – 8 August	3 days earlier
Saarbrücken	75 km	3 June – 9 August	4 days earlier
Nancy	103 km	3 June – 8 August	4 days earlier
Liège	120 km	4 June – 10 August	3 days earlier

Where to buy watermelon plants and seeds near Luxembourg

Buy plants ready to set out from 7 June to 9 August (from 17 May to 9 August for an unheated greenhouse); seed for raising your own is sown from 19 April to 12 July. Within 15 km of Luxembourg OpenStreetMap lists 9 garden centres, 3 plant nurseries, 7 markets and 13 farm shops (collected 20 October 2026).

Blaschenterhecken — plant nursery
13 km
Pépinière Jean Paul Krämer — plant nursery
14 km
Philippe Loschetter — plant nursery
15 km
Stand Sonnebierg — farm shop · sells: vegetables, fruits, jam, meat
10 km · sonnebierg.lu

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