When to plant watermelons in Lucerne: 28 June – 11 July

In Lucerne, watermelon: sow for seedlings from 10 May to 13 June; plant into a greenhouse from 7 June to 11 July; plant out into open ground from 28 June to 11 July. For plants and seeds, the places nearby include Milchautomat Buholz (farm shop, 4 km) and Hofladen Gemüse (farm shop, 5 km); addresses and opening hours are below.

Watermelon in Lucerne: soil, season and weather

In Lucerne the soil, not frost, sets the date: the last frost is over around 2 May, but the top 7 cm of soil reaches 18 °C — the minimum on the watermelon card — only around 28 June, 57 days later. 114 days separate planting out (28 June) from the first autumn frost (20 October); the card's 59 days to the first harvest leave 55 for picking, so a start 7 weeks late would still fit.

Last spring frost	2 May
Top 7 cm of soil at 18 °C	28 June, 57 days after the last frost
Into an unheated greenhouse	7 June – 11 July; June outside: 9.7 °C at night, 18.2 °C by day; card 18–35 °C
First autumn frost	20 October, 114 days after the start
Days in the bed to the first harvest (card)	59
First harvest, if planted in this window	26 August – 8 September
Days left for picking	55
Daylight	15:36 on 31 May, 15:53 on 28 June
Watering outdoors when fruiting (card)	every 5 days; the driest month, October, has 13 rainy days

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

Watermelon in Lucerne: care after planting

Planted on 28 June: in the first weeks water every 5 days.

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

28 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 Lucerne during the watermelon season

No month of the season averages above the watermelon card's 18–35 °C by day; the warmest, August, averages 19.4 °C. Months that stay below 18 °C even by day on average: September (15.4 °C) and October (12.1 °C). Nights average below 18 °C in every month of the season, from 4.1 °C to 11.5 °C.

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
June	18.2	9.7	177	19	15:53
July	19.3	11.5	215	20	15:33
August	19.4	11.4	192	16	14:16
September	15.4	7.8	160	16	12:37
October	12.1	4.1	134	13	10:57

ERA5 2016–2025, Open-Meteo

Watermelon in nearby cities

All the nearest cities on our list plant watermelon earlier than Lucerne; the closest date is in Bern, 7 days earlier.

City	Distance	Date	Difference
Zurich	41 km	11 June – 7 August	17 days earlier
Bern	66 km	21 June – 25 July	7 days earlier
Basel	79 km	5 June – 11 August	23 days earlier
St. Gallen	90 km	15 June – 9 August	13 days earlier
Fribourg	92 km	21 June – 28 July	7 days earlier
Locarno	105 km	30 May – 13 June	29 days earlier

Where to buy watermelon plants and seeds near Lucerne

Buy plants ready to set out from 28 June to 11 July (from 7 June to 11 July for an unheated greenhouse); seed for raising your own is sown from 10 May to 13 June. Within 15 km of Lucerne OpenStreetMap lists 7 garden centres, 1 farm-supply shop, 1 plant nursery, 16 markets and 37 farm shops (collected 27 October 2026).

Milchautomat Buholz — farm shop
Kastanienbaumstrasse 109, 6048 Horw · 24/7 · 4 km
Bio Hof Wandeler — farm shop
Gottsmänigen 7, 6203 Sempach Station · 11 km · biohofwandeler.ch
Rochushostatt — farm shop
24/7 · 12 km · rochushostatt.ch
Hofladen Gemüse — farm shop
Kastanienbaumstrasse 246 · 5 km · gmuesmattli.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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