When to plant crocuses in Boise: 27 September – end of December

In Boise, crocus: plant from 27 September to the end of December. For planting stock, the places nearby include North End Organic Nursery (garden centre, 4 km) and Zamzows (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 average daily temperature here stays above 0 °C all winter, and at least three months average 7 °C or less: our rule of thumb for the winter cold spring bulbs need. Sources: Iowa State University Extension, Wisconsin Horticulture Extension, UNH Extension, RHS.

Crocus in Boise: soil, season and weather

Nights then average below 0 °C in December–February; the coldest, January, averages -3.7 °C.

Planting	27 September – end of December
First autumn frost	27 October
Coldest nights	January, -3.7 °C
Soil back at 1 °C in spring	11 January
Daylight	11:58 on 27 September
Daylight at the winter solstice	8:56

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

Crocus in Boise: 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 Boise the average daily temperature stays at 10 °C or lower for about 23 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

All the nearest cities on our list plant crocus earlier than Boise; the closest date is in Salt Lake City, 1 day earlier.

City	Distance	Date	Difference
Elko	310 km	13 September – 15 November	14 days earlier
Idaho Falls	336 km	14 September – 14 November	13 days earlier
Missoula	400 km	6 September – 12 November	21 days earlier
Spokane	460 km	15 September – 23 November	12 days earlier
Helena	466 km	3 September – 5 November	24 days earlier
Salt Lake City	476 km	26 September – 23 December	1 day earlier

Where to buy crocus for planting in Boise

Planting stock goes into the ground from 27 September to the end of December; buy it before that. Within 15 km of Boise OpenStreetMap lists 4 garden centres, 2 farm-supply shops and 1 plant nursery (collected 20 October 2026).

Zamzows — garden centre
South Federal Way 3691, 83716 Boise · Mon–Fri 09:00–19:00; Sun 22:00–17:00; Sat 09:00–18:00 · 5 km
North End Organic Nursery — garden centre
West Chinden Boulevard 3777, 83714 Garden City · 4 km
Zamzows — garden centre
West Fairview Avenue 6313, 83704 Boise · 5 km
Cloverdale Nursery — garden centre
North Cloverdale Road 2528, 83713 Boise · 11 km
Zamzows — farm supply
East Overland Road 3650, 83642 Meridian · 12 km
Zamzows — farm supply
West State Street 6208, 83703 Boise · 8 km
Madeline George Garden Design & Nursery — plant nursery
West Hill Road Parkway 10550, 83714 Boise · 13 km · madelinegeorge.com

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