When to plant crocuses in Duluth: 28 September – 10 November

In Duluth, crocus: plant from 28 September to about 10 November. For planting stock, the places nearby include Growing Duluth (garden centre, 7 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 Duluth: soil, season and weather

Nights then average below 0 °C in November–March; the coldest, January, averages -11.8 °C.

Planting	28 September – 10 November
First autumn frost	28 October
Coldest nights	January, -11.8 °C
Soil back at 1 °C in spring	3 April
Daylight	11:54 on 28 September
Daylight at the winter solstice	8:32

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

Crocus in Duluth: 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 Duluth the average daily temperature stays at 10 °C or lower for about 29 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 Duluth, Winnipeg is 16 days earlier and Green Bay 2 days later.

City	Distance	Date	Difference
Minneapolis	219 km	24 September – 10 November	4 days earlier
Thunder Bay	279 km	23 September – 30 October	5 days earlier
Fargo	356 km	16 September – 4 November	12 days earlier
Green Bay	405 km	30 September – 17 November	2 days later
Madison	464 km	27 September – 20 November	1 day earlier
Winnipeg	508 km	12 September – 26 October	16 days earlier

Where to buy crocus for planting in Duluth

Planting stock goes into the ground from 28 September to about 10 November; buy it before that. Within 15 km of Duluth OpenStreetMap lists 1 garden centre and 1 market (collected 28 October 2026).

Growing Duluth — garden centre
Cody Street 6616, 55807 Duluth · 7 km · growingduluth.com
Farmer's Market — market
East 3rd Street 1324, 55805 Duluth · May–Oct: Wed 14:00–17:00, Sat 08:00–12:00; public holidays · 3 km · duluthfarmersmarket.com

Questions