When to plant watermelons in Bern: 21 June – 25 July

In Bern, watermelon: sow for seedlings from 3 May to 27 June; plant into a greenhouse from 31 May to 25 July; plant out into open ground from 21 June to 25 July. For plants and seeds, the places nearby include Katrins Lädeli (farm shop, 6 km) and Barry-Hof (farm shop, 9 km); addresses and opening hours are below.

Watermelon in Bern: soil, season and weather

In Bern the soil, not frost, sets the date: the last frost is over around 24 April, but the top 7 cm of soil reaches 18 °C — the minimum on the watermelon card — only around 21 June, 58 days later.

Last spring frost	24 April
Top 7 cm of soil at 18 °C	21 June, 58 days after the last frost
Into an unheated greenhouse	31 May – 25 July; May outside: 6.5 °C at night, 16.4 °C by day; card 18–35 °C
First autumn frost	3 November, 135 days after the start
Days in the bed to the first harvest (card)	59
First harvest, if planted in this window	19 August – 22 September
Days left for picking	76
Daylight	15:23 on 24 May, 15:54 on 21 June
Watering outdoors when fruiting (card)	every 5 days; the driest month, September, has 12 rainy days

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

Watermelon in Bern: care after planting

Planted on 21 June: in the first weeks water every 5 days.

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

21 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 Bern during the watermelon season

No month of the season averages above the watermelon card's 18–35 °C by day; the warmest, July, averages 23.7 °C. Months that stay below 18 °C even by day on average: October (13.9 °C) and November (6.9 °C). Nights average below 18 °C in every month of the season, from -0.3 °C to 12.9 °C.

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
June	22.1	11.4	120	15	15:52
July	23.7	12.9	120	15	15:32
August	23.7	12.6	99	12	14:16
September	19	8.9	94	12	12:37
October	13.9	4.8	99	12	10:57
November	6.9	-0.3	101	13	9:24

ERA5 2016–2025, Open-Meteo

Watermelon in nearby cities

Around Bern, Basel is 16 days earlier and Lucerne 7 days later.

City	Distance	Date	Difference
Fribourg	28 km	21 June – 28 July	same day
Neuchâtel	40 km	6 June – 19 August	15 days earlier
Lucerne	66 km	28 June – 11 July	7 days later
Basel	69 km	5 June – 11 August	16 days earlier
Lausanne	79 km	19 June – 11 August	2 days earlier
Sion	80 km	28 June – 10 July	7 days later

Where to buy watermelon plants and seeds near Bern

Buy plants ready to set out from 21 June to 25 July (from 31 May to 25 July for an unheated greenhouse); seed for raising your own is sown from 3 May to 27 June. Within 15 km of Bern OpenStreetMap lists 8 garden centres, 2 plant nurseries, 8 markets and 53 farm shops (collected 27 October 2026).

Katrins Lädeli — farm shop
Aegelseeweg 39, 3052 Zollikofen · 24/7 · 6 km
Barry-Hof — farm shop
Schüpberg 130 · 07:30–20:00 · 9 km · schuepberg.ch
Sigis Biohof — farm shop
Schwand 20, 3110 Münsingen · 11 km · sigis-biohof.ch
Hofladen Längfeld — farm shop
Längfeld 91a, 3510 Konolfingen · 14 km · myfarm.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.

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