When to plant crocuses in Pierre: 24 September – 19 November

In Pierre, crocus: plant from 24 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.

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 Pierre: soil, season and weather

Nights then average below 0 °C in November–March; the coldest, January, averages -10.3 °C.

Planting	24 September – 19 November
First autumn frost	24 October
Coldest nights	January, -10.3 °C
Soil back at 1 °C in spring	6 March
Daylight	12:07 on 24 September
Daylight at the winter solstice	8:51

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

Crocus in Pierre: 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 Pierre the average daily temperature stays at 10 °C or lower for about 26 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 Pierre, Rapid City is 12 days earlier and Lincoln 4 days later.

City	Distance	Date	Difference
Rapid City	233 km	12 September – 28 November	12 days earlier
Bismarck	274 km	15 September – 4 November	9 days earlier
Sioux Falls	302 km	21 September – 16 November	3 days earlier
Fargo	391 km	16 September – 4 November	8 days earlier
Grand Island	416 km	27 September – 1 December	3 days later
Lincoln	496 km	28 September – 7 December	4 days later

Where to buy crocus for planting in Pierre

Planting stock goes into the ground from 24 September to about 19 November; buy it before that. Within 15 km of Pierre OpenStreetMap lists 1 market (collected 28 October 2026).

The Alley Exchange — market
South Pierre Street 339, 57501 Pierre · 3 km

Questions