When to plant pumpkins in Sion: 28 June – 5 August

In Sion, pumpkin: sow for seedlings from 26 April to 24 June; plant into a greenhouse from 7 June to 5 August; plant out into open ground from 28 June to 5 August. For plants and seeds, the places nearby include Multiplants (garden centre, 6 km) and Agrol (garden centre, 13 km); addresses and opening hours are below.

Pumpkin in Sion: soil, season and weather

In Sion the soil, not frost, sets the date: the last frost is over around 8 May, but the top 7 cm of soil reaches 18 °C — the minimum on the pumpkin card — only around 28 June, 51 days later. 113 days separate planting out (28 June) from the first autumn frost (19 October); the card's 75 days to the first harvest leave 38 for picking, so a start 5 weeks late would still fit.

Last spring frost	8 May
Top 7 cm of soil at 18 °C	28 June, 51 days after the last frost
First autumn frost	19 October, 113 days after the start
Days in the bed to the first harvest (card)	75
First harvest, if planted in this window	11 September – 19 October
Days left for picking	38
Daylight	15:02 on 17 May, 15:46 on 28 June
Watering outdoors when fruiting (card)	every 5 days; the driest month, September, has 12 rainy days

The same dates in Sion hold for Cucumber, Bell Pepper, Eggplant, Zucchini and Watermelon.

Pumpkin in Sion: care after planting

Planted on 28 June: in the first weeks water every 4 days.

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

19 July — feed: nitrogen

Pests and diseases of pumpkin 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 Sion during the pumpkin season

About 539 mm of rain falls in the season; September is the driest month (91 mm) and June the wettest (125 mm).

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
June	20.2	9.5	125	18	15:46
July	21.8	11.1	115	16	15:27
August	22	10.8	103	14	14:12
September	17.7	7.1	91	12	12:36
October	13.7	2.9	105	12	10:59

ERA5 2016–2025, Open-Meteo

Pumpkin in nearby cities

Around Sion, Neuchâtel is 22 days earlier and Aosta 3 days later.

City	Distance	Date	Difference
Aosta	55 km	from 1 July	3 days later
Lausanne	65 km	19 June – 26 July	9 days earlier
Fribourg	65 km	21 June – 12 July	7 days earlier
Bern	80 km	21 June – 9 July	7 days earlier
Neuchâtel	91 km	6 June – 3 August	22 days earlier
Geneva	94 km	8 June – 23 July	20 days earlier

Where to buy pumpkin plants and seeds near Sion

Buy plants ready to set out from 28 June to 5 August (from 7 June to 5 August for an unheated greenhouse); seed for raising your own is sown from 26 April to 24 June. Within 15 km of Sion OpenStreetMap lists 4 garden centres, 1 farm-supply shop, 1 plant nursery, 1 market and 4 farm shops (collected 27 October 2026).

Lehmann Plantes — plant nursery
3 km · lehmannplantes.ch
K. Brandalise — farm supply
9 km
Agrol — garden centre
Route de Sion 90, 3960 Sierre · Mon–Thu 08:00–18:30; Fri 08:00–20:00; Sat 08:00–17:00 · 13 km · agrol.ch
Multiplants — garden centre
Route des Charmilles 42, 1963 Vétroz · 6 km · multiplants.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