Planting Zone 5b: Plants That Grow in USDA Hardiness Zone 5b

USDA hardiness zone 5b covers areas where the coldest winter night averages −15 °F to −10 °F (−26.1 °C to −23.3 °C). 2,865 ZIP codes in 25 states fall in zone 5b, mostly in Illinois, New York, Iowa, Nebraska and Wisconsin. PlantoScan lists 201 plants that survive winter outdoors in zone 5b.

Winter low (°F)
−15 °F to −10 °F
Winter low (°C)
−26.1 °C to −23.3 °C
US ZIP codes
2,865
Hardy plants
201

What Temperatures Define Hardiness Zone 5b?

Hardiness zone 5b is defined by an average annual extreme minimum temperature of −15 °F to −10 °F (−26.1 °C to −23.3 °C). This is the warmer half of zone 5, which spans −20 °F to −10 °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 5bbenefit 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 5a (−20 °F to −15 °F)Warmer: zone 6a (−10 °F to −5 °F) →

Which States Are in Hardiness Zone 5b?

Zone 5b appears in 25 states of the contiguous US. Illinois, New York, Iowa, Nebraska and Wisconsin have the most ZIP codes in zone 5b, based on the official 2023 USDA ZIP code table.

  • Illinois · 447 ZIPs
  • New York · 436 ZIPs
  • Iowa · 433 ZIPs
  • Nebraska · 291 ZIPs
  • Wisconsin · 263 ZIPs
  • Colorado · 217 ZIPs
  • Maine · 150 ZIPs
  • Michigan · 108 ZIPs
  • New Hampshire · 85 ZIPs
  • Pennsylvania · 68 ZIPs
  • Massachusetts · 56 ZIPs
  • Vermont · 46 ZIPs
  • Indiana · 45 ZIPs
  • Idaho · 44 ZIPs
  • Missouri · 39 ZIPs
  • Utah · 33 ZIPs
  • Montana · 32 ZIPs
  • Wyoming · 28 ZIPs
  • New Mexico · 18 ZIPs
  • Nevada · 10 ZIPs
  • South Dakota · 7 ZIPs
  • West Virginia · 6 ZIPs
  • Arizona · 1 ZIPs
  • California · 1 ZIPs
  • Oregon · 1 ZIPs

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

What Plants Grow in Zone 5b?

201 plants in PlantoScan's catalogue are hardy in zone 5b, meaning zone 5b falls inside their hardiness range. They include 73 trees, 29 shrubs, 46 perennials, herbs & flowers, 13 vines & climbers.

Trees for Zone 5b (73)

Shrubs for Zone 5b (29)

Perennials, Herbs & Flowers for Zone 5b (46)

Vines & Climbers for Zone 5b (13)

Succulents & Cacti for Zone 5b (4)

Grasses for Zone 5b (15)

Ferns for Zone 5b (8)

Other Plants for Zone 5b (13)

Which Popular Plants Aren't Hardy in Zone 5b?

These popular plants need a warmer zone than 5b 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 5b?

Successful zone 5b gardens rely on perennials, shrubs and trees rated to zone 5 or colder. Plants rated right at zone 5b 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 5b — 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.