Greenly Garden
Get the app
EN

When to plant crocuses in Green Bay: 30 September – 17 November

In Green Bay, crocus: plant from 30 September to about 17 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 Green Bay: soil, season and weather

Nights then average below 0 °C in November–March; the coldest, January, averages -9.8 °C.

Planting30 September – 17 November
First autumn frost30 October
Coldest nightsJanuary, -9.8 °C
Soil back at 1 °C in spring8 March
Daylight11:48 on 30 September
Daylight at the winter solstice8:49

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

Crocus in Green Bay: 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 Green Bay the average daily temperature stays at 10 °C or lower for about 27 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 Green Bay, Madison is 3 days earlier and Traverse City 10 days later.

CityDistanceDateDifference
Milwaukee165 km2 October – 25 November2 days later
Traverse City192 km10 October – 26 November10 days later
Madison196 km27 September – 20 November3 days earlier
Grand Rapids256 km4 October – 29 November4 days later
Rockford265 km28 September – 25 November2 days earlier
Chicago295 km7 October – 3 December7 days later

Where to buy crocus for planting in Green Bay

Planting stock goes into the ground from 30 September to about 17 November; buy it before that. Within 15 km of Green Bay OpenStreetMap lists 6 garden centres, 1 plant nursery and 2 markets (collected 20 October 2026).

Places: © OpenStreetMap contributors, ODbL.

Questions

When to plant crocuses in Green Bay?

In Green Bay, crocus: plant from 30 September to about 17 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 Green Bay?

Last spring frost around 29 April, first autumn frost around 30 October.

Other crops in Green Bay, with their dates