Planting Zone 6b: Plants That Grow in USDA Hardiness Zone 6b

USDA hardiness zone 6b covers areas where the coldest winter night averages −5 °F to 0 °F (−20.6 °C to −17.8 °C). 5,263 ZIP codes in 32 states fall in zone 6b, mostly in Ohio, Pennsylvania, Missouri, Kansas and West Virginia. PlantoScan lists 222 plants that survive winter outdoors in zone 6b.

Winter low (°F)
−5 °F to 0 °F
Winter low (°C)
−20.6 °C to −17.8 °C
US ZIP codes
5,263
Hardy plants
222

What Temperatures Define Hardiness Zone 6b?

Hardiness zone 6b is defined by an average annual extreme minimum temperature of −5 °F to 0 °F (−20.6 °C to −17.8 °C). This is the warmer half of zone 6, which spans −10 °F to 0 °F in total.

The value is a 30-year average of each winter's single coldest night, taken from 1991–2020 weather records for the 2023 USDA map. Individual winters regularly run a few degrees colder, so plants rated exactly to zone 6bbenefit from mulch and a sheltered spot. Gardeners who don't know their zone yet can look up their USDA hardiness zone by ZIP code before comparing plants.

← Colder: zone 6a (−10 °F to −5 °F)Warmer: zone 7a (0 °F to 5 °F) →

Which States Are in Hardiness Zone 6b?

Zone 6b appears in 32 states of the contiguous US. Ohio, Pennsylvania, Missouri, Kansas and West Virginia have the most ZIP codes in zone 6b, based on the official 2023 USDA ZIP code table.

  • Ohio · 784 ZIPs
  • Pennsylvania · 761 ZIPs
  • Missouri · 521 ZIPs
  • Kansas · 401 ZIPs
  • West Virginia · 364 ZIPs
  • New York · 320 ZIPs
  • Massachusetts · 281 ZIPs
  • Illinois · 260 ZIPs
  • Connecticut · 252 ZIPs
  • Indiana · 226 ZIPs
  • Michigan · 222 ZIPs
  • Kentucky · 187 ZIPs
  • Washington · 88 ZIPs
  • Idaho · 87 ZIPs
  • New Jersey · 76 ZIPs
  • New Mexico · 68 ZIPs
  • Oregon · 62 ZIPs
  • Utah · 57 ZIPs
  • Rhode Island · 40 ZIPs
  • California · 38 ZIPs
  • Colorado · 36 ZIPs
  • Virginia · 33 ZIPs
  • Arizona · 26 ZIPs
  • Nevada · 24 ZIPs
  • Oklahoma · 15 ZIPs
  • Maine · 10 ZIPs
  • North Carolina · 9 ZIPs
  • Maryland · 7 ZIPs
  • Texas · 4 ZIPs
  • New Hampshire · 2 ZIPs
  • Tennessee · 1 ZIPs
  • Montana · 1 ZIPs

Hardiness zones follow elevation and water, not state lines, so most states span several zones.

What Plants Grow in Zone 6b?

222 plants in PlantoScan's catalogue are hardy in zone 6b, meaning zone 6b falls inside their hardiness range. They include 82 trees, 33 shrubs, 49 perennials, herbs & flowers, 14 vines & climbers.

Trees for Zone 6b (82)

Shrubs for Zone 6b (33)

Perennials, Herbs & Flowers for Zone 6b (49)

Vines & Climbers for Zone 6b (14)

Succulents & Cacti for Zone 6b (4)

Grasses for Zone 6b (17)

Ferns for Zone 6b (10)

Other Plants for Zone 6b (13)

Which Popular Plants Aren't Hardy in Zone 6b?

These popular plants need a warmer zone than 6b to survive winter outdoors. Grow them as houseplants, in containers that move indoors before the first frost, or as annuals replanted each spring.

How Do You Garden Successfully in Zone 6b?

Successful zone 6b gardens rely on perennials, shrubs and trees rated to zone 6 or colder. Plants rated right at zone 6b survive typical winters but benefit from mulch, windbreaks and a spot near a warm wall.

A hardiness zone describes winter cold only. Planting dates follow your local last spring frost and first fall frost, which differ by weeks within zone 6b — a last frost date calculator by ZIP code gives the dates for your garden. Summer heat, rainfall and soil drainage decide whether a hardy plant thrives. Microclimates matter as well: raised beds, slopes and paved areas warm up faster, while low ground collects cold air on still nights.

Zone temperatures and ZIP codes: 2023 USDA Plant Hardiness Zone Map, USDA Agricultural Research Service and the PRISM Climate Group, Oregon State University. Plant hardiness ranges come from PlantoScan's plant database and are estimates — local conditions, cultivars and winter protection change what survives.