USDA hardiness zone
Zone 3b
Rolled up from the 236 ZIP codes in our data that are classified zone 3b, covering 4 nurseries and garden centers across 3 cities we track in this zone.
Average minimum winter temperature
-35°F
Last spring frost range
May 4–Jun 6
First fall frost range
Aug 25–Oct 9
Average frost-free growing season
127 days
Average monthly temperature
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 6.3° | 10.7° | 23.5° | 38.7° | 51.9° | 61.7° | 66.4° | 64.6° | 55.4° | 41.2° | 25.5° | 12.5° |
NOAA 1991–2020 Climate Normals, averaged across this zone's member ZIPs.
Crops by frost hardiness
What grows here, and when
This zone's own last-frost dates range across May 4–Jun 6. Hardy and semi-hardy crops can go in before that date; tender and very-tender crops need to wait until after it. See each crop's own guide for exact windows at a specific location in this zone.
Planting windows and crop timing here are computed from USDA/NOAA climate data and the university extension sources cited below, not a site visit or soil test. Treat this as a starting point: local conditions vary, and a local nursery or extension office can advise on your exact site. See our full Disclaimer.
Hardy (49)
- Apple (bare-root fruit tree)
- Apricot (bare-root fruit tree)
- Asparagus
- Bachelor's Button (Cornflower)
- Bare-root rose
- Blackberry
- Blueberry
- Broccoli
- Brussels Sprouts
- Cabbage
- Calendula
- Catnip/Catmint
- Cherry (sweet/tart, bare-root fruit tree)
- Chives
- Collards
- Currant
- Deciduous shade tree (generic, e.g. maple/oak, bare-root or B&B)
- Elderberry
- Evergreen shrub (B&B/potted, e.g. arborvitae, boxwood)
- Flowering deciduous shrub (generic, e.g. lilac/forsythia)
- Garden Peas
- Garlic
- Gooseberry
- Kale
- Kohlrabi
- Larkspur
- Lavender
- Lettuce
- Mint
- Onion (bulb)
- Oregano
- Peach (bare-root fruit tree)
- Pear (bare-root fruit tree)
- Plum (bare-root fruit tree)
- Radish
- Raspberry
- Rhubarb
- Rutabaga
- Sage
- Snapdragon
- Snow Peas
- Spinach
- Strawberry
- Sweet Alyssum
- Sweet Pea
- Table/Bunch Grape
- Tarragon
- Thyme
- Turnip
Semi-hardy (16)
Tender (20)
Zone 3b means an average annual extreme minimum winter temperature of -35°F to -30°F on the 2023 USDA Plant Hardiness Zone Map (USDA/ARS with the PRISM Climate Group at Oregon State University, 1991-2020 records). Every ZIP behind this rollup carries its zone matched by centroid against the map, not by its polygon boundary, through phzmapi.org's ZIP-level derivation.
The frost dates above are medians across this zone's own ZIPs, and the spread beneath that median is the practical fact: a fall crop timed to this zone's own first frost can be right on schedule in one town and weeks too late in another that shares the same zone label. Check your own ZIP on the crop guides before trusting the median above.
The nurseries we track in zone 3b cluster on Minnesota's Iron Range, around Virginia, Eveleth, and Mountain Iron. Every ZIP in this band sits in Minnesota.
Cities we track in zone 3b
- Virginia, MN (2)
- Eveleth, MN (1)
- Mountain Iron, MN (1)
Nearby zones
All zones
USDA 2023 Plant Hardiness Zone Map (zone boundaries, via the phzmapi.org ZIP-level derivation) and NOAA 1991–2020 Climate Normals (frost dates, growing season, monthly temperatures).