USDA hardiness zone
Zone 6b
Rolled up from the 5,333 ZIP codes in our data that are classified zone 6b, covering 3,373 nurseries and garden centers across 832 cities we track in this zone.
Average minimum winter temperature
-5°F
Last spring frost range
Mar 29–Jun 21
First fall frost range
Sep 4–Nov 12
Average frost-free growing season
180 days
Average monthly temperature
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 29° | 31.9° | 40.3° | 50.9° | 60.9° | 69.6° | 74.1° | 72.6° | 65.4° | 53.8° | 42.4° | 33.3° |
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 Mar 29–Jun 21. 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 6b means an average annual extreme minimum winter temperature of -5°F to 0°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 here carries its zone matched by centroid against the map, not by its polygon boundary, via phzmapi.org's ZIP-level derivation.
The growing-season figure above hides a wide real range within this zone's own ZIPs, from barely over four months at the coldest of them to well past seven at the mildest. A hardy crop's fall-planting window can land five or six weeks apart between two towns that share this exact zone label, which is the reason this site never states a bare timing rule without your own ZIP behind it.
We track nurseries across 27 states in zone 6b, from Arizona and California to West Virginia, with Cincinnati, OH carrying the most, followed by Rochester, NY and Pittsburgh, PA.
Cities we track in zone 6b
- Cincinnati, OH (74)
- Rochester, NY (68)
- Pittsburgh, PA (51)
- Indianapolis, IN (45)
- Kansas City, MO (45)
- Buffalo, NY (41)
- Springfield, MO (36)
- Dayton, OH (34)
- Columbus, OH (32)
- Toledo, OH (29)
- Columbia, MO (28)
- Erie, PA (26)
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).