When to plant crocuses in Sion: 19 September – 19 November

In Sion, crocus: plant from 19 September to about 19 November. For planting stock, the places nearby include Ferme Vuissoz (farm shop, 2 km) and bioverger.ch (farm shop, 4 km); addresses and opening hours are below.

Bulbs are best planted early in the window: late-planted bulbs may flower later or less well. Late planting works only while the soil can be dug. Mulch after planting.

The date is about two weeks before the average daily temperature here falls below 0 °C (ten years of weather): an estimate, not the day the ground freezes, and a cold spell can freeze it earlier. Sources: Iowa State University Extension, Wisconsin Horticulture Extension, UNH Extension, RHS, how the ground freezes (NRC Canada, CBD-26).

Crocus in Sion: soil, season and weather

Nights then average below 0 °C in November–April; the coldest, January, averages -7.3 °C.

Planting	19 September – 19 November
First autumn frost	19 October
Coldest nights	January, -7.3 °C
Soil back at 1 °C in spring	23 January
Daylight	12:23 on 19 September
Daylight at the winter solstice	8:37

The same dates in Sion hold for Garlic, Tulip, Daffodil and Hyacinth.

Crocus in Sion: depth, winter cold, pests and pets

Plant Dutch crocuses (Crocus vernus) about 12 cm deep and 9 cm apart; smaller species go 7–10 cm deep (RHS).

In Sion the average daily temperature stays at 10 °C or lower for about 33 weeks a year (our estimate from ten years of monthly weather). For this bulb Wisconsin Horticulture Extension gives a cold period of 15–17 weeks at about 2–10 °C. The winter here gives that in the ground, so the bulbs need no pre-chilling.

Crocuses multiply on their own (they naturalise); in a lawn, hold off mowing until their leaves die back (RHS).

Birds, squirrels and rodents damage crocuses; planting under metal mesh may reduce losses (RHS). Spring crocus gives dogs and cats vomiting and diarrhoea; do not confuse it with autumn crocus (Colchicum), which is very toxic (Pet Poison Helpline).

Sources: RHS, Wisconsin Horticulture Extension, Pet Poison Helpline.

Crocus in nearby cities

Around Sion, Aosta is 39 days earlier and Neuchâtel 40 days later.

City	Distance	Date	Difference
Aosta	55 km	11 August – 22 October	39 days earlier
Fribourg	65 km	7 October – 30 December	18 days later
Bern	80 km	4 October – 21 December	15 days later
Neuchâtel	91 km	29 October – end of December	40 days later
Geneva	94 km	18 October – end of December	29 days later
Annecy	101 km	15 October – end of December	26 days later

Where to buy crocus for planting in Sion

Planting stock goes into the ground from 19 September to about 19 November; buy it before that. 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).

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
Point Vert — garden centre
Mon–Thu 08:00–18:30; Sat 08:00–17:00; Fri 08:00–20:00 · 5 km
Marché de la vieille ville — market
Fri 08:00–14:00 · 0 km · mvvsion.ch
Ferme Vuissoz — farm shop
Chemin de Maragnène 40, 1950 · 2 km · ferme-vuissoz.ch
Self-Service Bio — farm shop
Feb 15–Dec 31 Mon–Sat 10:00–19:00 · 14 km · reynard-biotop.ch
bioverger.ch — farm shop
24/7 · 4 km · bioverger.ch
Chez Cheseaux — farm shop
Mon–Sun 07:00–19:00 · 15 km

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