Greenly Garden

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

In Sion, hyacinth: plant from 19 September to about 19 November. For planting stock, the places nearby include Ferme Vuissoz (farm shop, 2 km) and Point Vert (garden centre, 5 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).

Hyacinth in Sion: soil, season and weather

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

Planting19 September – 19 November
First autumn frost19 October
Coldest nightsJanuary, -7.3 °C
Soil back at 1 °C in spring23 January
Daylight12:23 on 19 September
Daylight at the winter solstice8:37

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

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

Plant hyacinths 10 cm deep, at least 7.5 cm apart (RHS). In the ground hyacinths are fully hardy, but in containers they can be frost tender in cold winters (RHS); here winter nights average below 0 °C, so wrap the pots or move them to a sheltered spot.

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 12–15 weeks at about 2–10 °C. The winter here gives that in the ground, so the bulbs need no pre-chilling.

Flowers get smaller in the years after planting: for full spikes, replace the bulbs or add a few new ones each autumn (RHS).

If squirrels are a problem, protect the bulbs with wire mesh (RHS). Hyacinths are toxic to dogs, cats and horses: intense vomiting and diarrhoea (ASPCA).

Sources: RHS, Wisconsin Horticulture Extension, ASPCA.

Hyacinth in nearby cities

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

CityDistanceDateDifference
Aosta55 km11 August – 22 October39 days earlier
Fribourg65 km7 October – 30 December18 days later
Bern80 km4 October – 21 December15 days later
Neuchâtel91 km29 October – end of December40 days later
Geneva94 km18 October – end of December29 days later
Annecy101 km15 October – end of December26 days later

Where to buy hyacinth 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).

Places: © OpenStreetMap contributors, ODbL.

Questions

When to plant hyacinths in Sion?

In Sion, hyacinth: plant from 19 September to about 19 November. 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.

When is the last spring frost in Sion?

Last spring frost around 8 May, first autumn frost around 19 October.

Other crops in Sion, with their dates