When to plant watermelons in Lausanne: 19 June – 11 August

In Lausanne, watermelon: sow for seedlings from 1 May to 14 July; plant into a greenhouse from 29 May to 11 August; plant out into open ground from 19 June to 11 August. For plants and seeds, the places nearby include Ferme agroécologique de Rovéréaz (farm shop, 3 km) and Kiosque à fruits (farm shop, 4 km); addresses and opening hours are below.

Watermelon in Lausanne: soil, season and weather

In Lausanne the soil, not frost, sets the date: the last frost is over around 12 April, but the top 7 cm of soil reaches 18 °C — the minimum on the watermelon card — only around 19 June, 68 days later.

Last spring frost	12 April
Top 7 cm of soil at 18 °C	19 June, 68 days after the last frost
Into an unheated greenhouse	29 May – 11 August; May outside: 7.6 °C at night, 15.6 °C by day; card 18–35 °C
First autumn frost	20 November, 154 days after the start
Days in the bed to the first harvest (card)	59
First harvest, if planted in this window	17 August – 9 October
Days left for picking	95
Daylight	15:15 on 22 May, 15:50 on 19 June
Watering outdoors when fruiting (card)	every 5 days; the driest month, August, has 12 rainy days

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

Watermelon in Lausanne: care after planting

Planted on 19 June: in the first weeks water every 5 days.

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

19 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 Lausanne during the watermelon season

No month of the season averages above the watermelon card's 18–35 °C by day; the warmest, July, averages 22.7 °C. Months that stay below 18 °C even by day on average: October (13.9 °C) and November (7.8 °C). Nights average below 18 °C in every month of the season, from 2.8 °C to 15 °C.

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
June	20.9	12.9	148	16	15:48
July	22.7	14.8	144	15	15:29
August	22.7	15	131	12	14:14
September	18.4	11.8	140	14	12:36
October	13.9	7.8	134	12	10:58
November	7.8	2.8	148	15	9:26

ERA5 2016–2025, Open-Meteo

Watermelon in nearby cities

Around Lausanne, Neuchâtel is 13 days earlier and Sion 9 days later.

City	Distance	Date	Difference
Fribourg	50 km	21 June – 28 July	2 days later
Geneva	52 km	8 June – 8 August	11 days earlier
Neuchâtel	57 km	6 June – 19 August	13 days earlier
Sion	65 km	28 June – 10 July	9 days later
Annecy	78 km	19 June – 5 August	same day
Bern	79 km	21 June – 25 July	2 days later

Where to buy watermelon plants and seeds near Lausanne

Buy plants ready to set out from 19 June to 11 August (from 29 May to 11 August for an unheated greenhouse); seed for raising your own is sown from 1 May to 14 July. Within 15 km of Lausanne OpenStreetMap lists 5 garden centres, 4 farm-supply shops, 5 plant nurseries, 19 markets and 58 farm shops (collected 27 October 2026).

Ferme Baudet — farm shop
Chemin du Village 12, 1032 Romanel-sur-Lausanne · Fri 13:30–18:30 · 5 km · facebook.com
Ferme agroécologique de Rovéréaz — farm shop
Route d'Oron 27, 1010 Lausanne · Mon–Fri 09:00–18:00; Sat 09:00–16:00 · 3 km · rovereaz.ch
Kiosque à fruits — farm shop
Route de la Blécherette 82, 1052 Le Mont-sur-Lausanne · Fri 14:00–18:00; Sat 09:00–12:00 · 4 km · hennyfruits.ch
La Dubarde — farm shop
Chemin du Châtaignier 2, 1052 Le Mont-sur-Lausanne · Wed–Sat 11:00–20:00; Sun 11:00–19:00 · 5 km · dubarde.ch

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