When to plant watermelons in St. Gallen: 15 June – 9 August

In St. Gallen, watermelon: sow for seedlings from 27 April to 12 July; plant into a greenhouse from 25 May to 9 August; plant out into open ground from 15 June to 9 August. For plants and seeds, the places nearby include Gübsenhof (farm shop, 5 km); addresses and opening hours are below.

Watermelon in St. Gallen: soil, season and weather

In St. Gallen the soil, not frost, sets the date: the last frost is over around 14 April, but the top 7 cm of soil reaches 18 °C — the minimum on the watermelon card — only around 15 June, 62 days later.

Last spring frost	14 April
Top 7 cm of soil at 18 °C	15 June, 62 days after the last frost
Into an unheated greenhouse	25 May – 9 August; May outside: 8.4 °C at night, 17.2 °C by day; card 18–35 °C
First autumn frost	18 November, 156 days after the start
Days in the bed to the first harvest (card)	59
First harvest, if planted in this window	13 August – 7 October
Days left for picking	97
Daylight	15:13 on 18 May, 15:56 on 15 June
Watering outdoors when fruiting (card)	every 5 days; the driest month, November, has 13 rainy days

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

Watermelon in St. Gallen: care after planting

Planted on 15 June: in the first weeks water every 5 days.

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

15 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 St. Gallen 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 (14.5 °C) and November (7.9 °C). Nights average below 18 °C in every month of the season, from 2 °C to 14.9 °C.

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
June	22.7	13.4	131	15	15:56
July	23.7	14.9	130	16	15:36
August	23.5	14.8	155	13	14:18
September	19.1	11.1	108	12	12:37
October	14.5	7.2	98	12	10:56
November	7.9	2	89	13	9:21

ERA5 2016–2025, Open-Meteo

Watermelon in nearby cities

Around St. Gallen, Locarno is 16 days earlier and Lucerne 13 days later.

City	Distance	Date	Difference
Zurich	63 km	11 June – 7 August	4 days earlier
Lucerne	90 km	28 June – 11 July	13 days later
Freiburg im Breisgau	130 km	4 June – 7 August	11 days earlier
Basel	135 km	5 June – 11 August	10 days earlier
Bellinzona	139 km	19 June – 6 August	4 days later
Locarno	146 km	30 May – 13 June	16 days earlier

Where to buy watermelon plants and seeds near St. Gallen

Buy plants ready to set out from 15 June to 9 August (from 25 May to 9 August for an unheated greenhouse); seed for raising your own is sown from 27 April to 12 July. Within 15 km of St. Gallen OpenStreetMap lists 7 garden centres, 3 farm-supply shops, 1 plant nursery, 3 markets and 24 farm shops (collected 27 October 2026).

Gübsenhof — farm shop · sells: apple, eggs, potatoes, nut, onion
Mon–Sun 07:45–17:30 · 5 km
Landi — garden centre
5 km
Forschungsfläche Bäume — plant nursery
5 km
Landi — farm supply
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.

Questions