When to plant watermelons in Geneva: 8 June – 8 August

In Geneva, watermelon: sow for seedlings from 20 April to 11 July; plant into a greenhouse from 18 May to 8 August; plant out into open ground from 8 June to 8 August. For plants and seeds, the places nearby include Union Maraichère de Genève (farm shop, 5 km) and Ô Champs Paysans (farm shop, 6 km); addresses and opening hours are below.

Watermelon in Geneva: soil, season and weather

In Geneva the soil, not frost, sets the date: the last frost is over around 10 April, but the top 7 cm of soil reaches 18 °C — the minimum on the watermelon card — only around 8 June, 59 days later.

Last spring frost	10 April
Top 7 cm of soil at 18 °C	8 June, 59 days after the last frost
Into an unheated greenhouse	18 May – 8 August; May outside: 7.9 °C at night, 17.9 °C by day; card 18–35 °C
First autumn frost	17 November, 162 days after the start
Days in the bed to the first harvest (card)	59
First harvest, if planted in this window	6 August – 6 October
Days left for picking	103
Daylight	14:47 on 11 May, 15:40 on 8 June
Watering outdoors when fruiting (card)	every 5 days; the driest month, August, has 9 rainy days

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

Watermelon in Geneva: care after planting

Planted on 8 June: in the first weeks water every 5 days.

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

8 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 Geneva during the watermelon season

No month of the season averages above the watermelon card's 18–35 °C by day; the warmest, August, averages 25.9 °C. Months that stay below 18 °C even by day on average: October (15.8 °C) and November (9.3 °C). Nights average below 18 °C in every month of the season, from 1.9 °C to 14.9 °C.

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
June	23.5	13.1	104	13	15:45
July	25.8	14.9	88	11	15:26
August	25.9	14.7	80	9	14:12
September	20.8	11	85	10	12:36
October	15.8	6.9	113	11	10:59
November	9.3	1.9	122	14	9:28

ERA5 2016–2025, Open-Meteo

Watermelon in nearby cities

Around Geneva, Chambéry is 5 days earlier and Aosta 23 days later.

City	Distance	Date	Difference
Annecy	32 km	19 June – 5 August	11 days later
Lausanne	52 km	19 June – 11 August	11 days later
Chambéry	72 km	3 June – 11 August	5 days earlier
Sion	94 km	28 June – 10 July	20 days later
Fribourg	102 km	21 June – 28 July	13 days later
Aosta	105 km	1 July – 13 July	23 days later

Where to buy watermelon plants and seeds near Geneva

Buy plants ready to set out from 8 June to 8 August (from 18 May to 8 August for an unheated greenhouse); seed for raising your own is sown from 20 April to 11 July. Within 15 km of Geneva OpenStreetMap lists 16 garden centres, 2 farm-supply shops, 8 markets and 23 farm shops (collected 27 October 2026).

La Plaine du Loup — farm shop
Chemin des Cornaches 1, 1233 · Tue–Fri 09:00–12:00, 14:00–18:00; Sat 09:00–16:30 · 7 km · lemarchedelaplaineduloup.com
La Ferme de Corly — farm shop
Route de Corly 4, 74100 Vétraz-Monthoux · 24/7 · 10 km · fermedecorly.fr
Union Maraichère de Genève — farm shop
Route de Base 45, 1258 Perly · Mon 14:00–18:00; Tue–Fri 10:00–18:00; Sat 09:00–13:00 · 5 km
Ô Champs Paysans — farm shop
Route de Rozon 350, 74160 Collonges-sous-Salève · Wed–Fri 14:30–19:00; Sat 09:00–18:00 · 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.

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