When to plant watermelons in Locarno: 30 May – 13 June

In Locarno, watermelon: sow for seedlings from 11 April to 16 May; plant into a greenhouse from 9 May to 13 June; plant out into open ground from 30 May to 13 June. For plants and seeds, the places nearby include Orto mio (farm shop, 4 km) and Orticoltura Regusci (farm shop, 15 km); addresses and opening hours are below.

Watermelon in Locarno: soil, season and weather

In the median year the top 7 cm of soil in Locarno does not reach 18 °C, the minimum on the watermelon card, before August; the date follows the last frost (23 May), and the bed stays cooler than the card asks. 115 days separate planting out (30 May) from the first autumn frost (22 September); the card's 59 days to the first harvest leave 56 for picking, so a start 8 weeks late would still fit.

Last spring frost	23 May
Into an unheated greenhouse	9 May – 13 June; May outside: 1 °C at night, 11.1 °C by day; card 18–35 °C
First autumn frost	22 September, 115 days after the start
Days in the bed to the first harvest (card)	59
First harvest, if planted in this window	28 July – 11 August
Days left for picking	56
Daylight	14:23 on 2 May, 15:28 on 30 May
Watering outdoors when fruiting (card)	every 5 days; the driest month, September, has 16 rainy days

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

Watermelon in Locarno: care after planting

Planted on 30 May: in the first weeks water every 5 days.

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

30 May — 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 Locarno during the watermelon season

No month of the season averages above the watermelon card's 18–35 °C by day; the warmest, July, averages 18.4 °C. Months that stay below 18 °C even by day on average: May (11.1 °C), June (16.5 °C) and September (13.7 °C). Nights average below 18 °C in every month of the season, from 1 °C to 8.2 °C.

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
May	11.1	1	215	20	14:57
June	16.5	6.4	239	21	15:45
July	18.4	8.2	184	20	15:26
August	18.3	8.1	227	18	14:12
September	13.7	4.3	156	16	12:36

ERA5 2016–2025, Open-Meteo

Watermelon in nearby cities

Around Locarno, Milan is 18 days earlier and Bellinzona 20 days later.

City	Distance	Date	Difference
Bellinzona	17 km	19 June – 6 August	20 days later
Lugano	22 km	29 May – 26 August	1 day earlier
Como	46 km	29 May – 14 August	1 day earlier
Novara	81 km	23 May – 13 August	7 days earlier
Milan	85 km	12 May – 21 August	18 days earlier
Bergamo	85 km	31 May – 9 August	1 day later

Where to buy watermelon plants and seeds near Locarno

Buy plants ready to set out from 30 May to 13 June (from 9 May to 13 June for an unheated greenhouse); seed for raising your own is sown from 11 April to 16 May. Within 15 km of Locarno OpenStreetMap lists 5 garden centres, 1 farm-supply shop and 4 farm shops (collected 27 October 2026).

Agriturismo Alpe Zalto — farm shop
Alpe Zalto, 6950 · "Periodo di apertura: Da metà maggio a fine agosto. Settembre e ottobre su riservazione." · 15 km · agriturismo.ch
Orticoltura Regusci — farm shop
I Casasc 5, 6528 Camorino · 15 km
Orto mio — farm shop
Mon–Sun 00:00–00:00 · 4 km
Hacker — garden centre
4 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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