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Home Hardiness Zone Chart

Hardiness Zone Chart

The 2023 USDA plant hardiness zones on one chart. Find your half zone in °F or °C, look up 23 cities and see which of 30 garden plants come through your winters.

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Figure 1. The Hardiness Zone Chart poster shows all 26 USDA half zones in °F and °C, 30 plants by zone and the garden microclimates. Select it to open full size, then zoom in.

Contents

  1. 1Finding your zone
  2. 2What grows in each zone
  3. 3How the map is made
  4. 4Microclimates
  5. 5What zones leave out
  6. 6Practical rules
  7. Sources and notes

1.Finding your zone

A zone is set by the average coldest winter temperature: the 30-year average of each winter’s single coldest night. Enter that number below. The thermometer fills to it and the ladder marks your half zone. Switch to °C to read every zone in Celsius.

1a−60 to −55°F
1b−55 to −50°F
2a−50 to −45°F
2b−45 to −40°FUtqiagvik
3a−40 to −35°FFairbanks
3b−35 to −30°FInternational Falls
4a−30 to −25°FBismarck
4b−25 to −20°F
5a−20 to −15°FMinneapolisAnchorage
5b−15 to −10°F
6a−10 to −5°FDenver
6b−5 to 0°FChicagoKansas City
7a0 to 5°FBoston
7b5 to 10°FNew YorkNashville
8a10 to 15°FWashingtonAtlanta
8b15 to 20°FDallas
9a20 to 25°FSeattle
9b25 to 30°FHouston
10a30 to 35°FPhoenix
10b35 to 40°FLos Angeles
11a40 to 45°FMiami
11b45 to 50°FKey West
12a50 to 55°F
12b55 to 60°FHonolulu
13a60 to 65°F
13b65 to 70°FSan Juan

Figure 2. Each tile is a 5°F half zone. Discs mark the 13 whole zones of 10°F; a is the colder half, b the warmer.

Your coldest winter temperature

USDA hardiness zone 6a tile
Your half zone Zone 6a −10 to −5°F · −23.3 to −20.6°C

6a is the colder half of zone 6, which covers −10 to 0°F. The warmer half, 6b, runs −5 to 0°F. The a/b half matters most for borderline plants.

Zones of 23 cities on the 2023 map

Zone at a downtown ZIP code on the 2023 map; suburbs, hills and shorelines can differ by a half zone or more.

Find your exact zone by ZIP code at planthardiness.ars.usda.gov

2.What grows in each zone

Pick a zone to sort 30 fruit trees, berries, perennial vegetables, ornamentals and tropicals by typical winter hardiness. Variety, rootstock and site matter, so treat the ranges as a starting point.

typical rangehardy varieties or protectionyour zoneBars run from zone 1 (left) to 13 (right).

Zone 6 (−10 to 0°F): of the 30 plants, 20 grow, 2 need protection or a hardy variety, and 8 do not suit it. Numbers on the filter buttons count the plants that grow.

Grows20

Apple, hardy in zones 4–9

Applezones 4–9

Zone 6 is inside its range. Hardy cultivars and rootstocks to zone 3.

Pear (European), hardy in zones 4–8

Pear (European)zones 4–8

Zone 6 is inside its range. Needs winter chill to fruit well.

Peach, hardy in zones 5–9

Peachzones 5–9

Zone 6 is inside its range. Blooms early: spring frost is the usual loss.

Sweet cherry, hardy in zones 5–8

Sweet cherryzones 5–8

Zone 6 is inside its range. Prefers cool, dry summers.

Sour cherry, hardy in zones 3–8

Sour cherryzones 3–8

Zone 6 is inside its range. Far hardier than sweet cherry.

Highbush blueberry, hardy in zones 3–8

Highbush blueberryzones 3–8

Zone 6 is inside its range. Needs acid soil, about pH 4.5–5.5.

Red raspberry, hardy in zones 4–8

Red raspberryzones 4–8

Zone 6 is inside its range. Fall-bearing types fruit on new canes.

Blackberry, hardy in zones 5–8

Blackberryzones 5–8

Zone 6 is inside its range. 'Illini Hardy' to zone 4; thornless less hardy.

Grape (American), hardy in zones 5–8

Grape (American)zones 5–8

Zone 6 is inside its range. European wine grapes about 6–10.

Hardy kiwi, hardy in zones 3–8

Hardy kiwizones 3–8

Zone 6 is inside its range. Fuzzy grocery kiwi only 7–9.

Asparagus, hardy in zones 2–9

Asparaguszones 2–9

Zone 6 is inside its range. Needs a winter rest to crop well.

Rhubarb, hardy in zones 3–8

Rhubarbzones 3–8

Zone 6 is inside its range. Likes cold winters; sulks in heat.

Sage, hardy in zones 4–8

Sagezones 4–8

Zone 6 is inside its range. Rots in wet winter soil.

English lavender, hardy in zones 5–9

English lavenderzones 5–9

Zone 6 is inside its range. Drainage matters more than cold.

Rugosa rose, hardy in zones 2–7

Rugosa rosezones 2–7

Zone 6 is inside its range. Other roses vary widely: check the tag.

Lilac, hardy in zones 3–7

Lilaczones 3–7

Zone 6 is inside its range. Needs cold winters to bloom well.

Peony, hardy in zones 3–8

Peonyzones 3–8

Zone 6 is inside its range. Herbaceous; needs winter chill to flower.

Hosta, hardy in zones 3–9

Hostazones 3–9

Zone 6 is inside its range. Shade lover; dies back in winter.

Panicle hydrangea, hardy in zones 3–8

Panicle hydrangeazones 3–8

Zone 6 is inside its range. Blooms on new wood: reliable flowers.

Bigleaf hydrangea, hardy in zones 6–9

Bigleaf hydrangeazones 6–9

Zone 6 is inside its range. Flower buds often frost-killed at the cold end.

With protection2

Fig, hardy in zones 7–10

Figzones 7–10

Hardy varieties or winter protection reach zone 6. Zone 6 with winter wrap; may die back.

Banana, hardy in zones 10–11

Bananazones 10–11

Hardy varieties or winter protection reach zone 5. Hardy Musa basjoo: roots survive to zone 5.

Too cold or too hot8

Olive, hardy in zones 8–10

Olivezones 8–10

Too cold: needs zone 8 or warmer. A few cultivars reach zone 7.

Orange, hardy in zones 9–11

Orangezones 9–11

Too cold: needs zone 9 or warmer. Meyer lemon is also 9–11.

Avocado, hardy in zones 9–12

Avocadozones 9–12

Too cold: needs zone 9 or warmer. Mexican types are the hardiest.

Rosemary, hardy in zones 8–10

Rosemaryzones 8–10

Too cold: needs zone 8 or warmer. Pot it and bring it in below zone 8.

Globe artichoke, hardy in zones 7–10

Globe artichokezones 7–10

Too cold: needs zone 7 or warmer. Grown as an annual north of zone 7.

Windmill palm, hardy in zones 7–11

Windmill palmzones 7–11

Too cold: needs zone 7 or warmer. One of the hardiest palms.

Tropical hibiscus, hardy in zones 9–11

Tropical hibiscuszones 9–11

Too cold: needs zone 9 or warmer. Grow in a pot and overwinter indoors elsewhere.

Bougainvillea, hardy in zones 9b–10b

Bougainvilleazones 9b–10b

Too cold: needs zone 9b or warmer. Often listed to 11; frost burns the tops.

Ranges from NC State Extension Plant Toolbox, Missouri Botanical Garden Plant Finder, Oregon State Landscape Plants and Illinois Extension. A range that starts at 9b begins in the warmer half of zone 9.

3.How the map is made

A zone is a 30-year average, not a record low. USDA released the current map on November 15, 2023, with Oregon State University’s PRISM Climate Group. The example below works through the idea for one made-up weather station.

Each winter’s coldest night at an example station (illustrative numbers, not a real station)

Winter 1 of 30 (1991): −12°FHover over or tap the bars, or use the slider.
  1. Record each winter’s single coldest night.
  2. Average those lows over 30 winters (1991–2020).
  3. The average sets the zone: 10°F per zone, split into a and b halves of 5°F.
The 2023 map in figures
13,412weather stations, up from 7,983 for the 2012 map ARS news release figure; USDA’s Map Creation page gives 13,625.
1991–202030 winters of data; the 2012 map used 1976–2005
½ zonewarmer for about half of the country; the other half stayed in the same half zone
12 & 13the warmest zones, above 50°F and 60°F, found only in Hawaii and Puerto Rico; first added on the 2012 map

Example shift: Minneapolis

USDA hardiness zone 4b tile
2012 map
USDA hardiness zone 5a tile
2023 map

USDA: zone changes are not reliable evidence of climate change on their own, because of year-to-year variability, better mapping methods and more stations.

4.Microclimates

Every yard has warmer and colder corners than its zone. Select a numbered spot in the garden, or a name in the list, to see why that corner runs warm or cold.

Model garden seen from above: a lake, a house with a sunny south bed and a shady north bed, a stone patio, town buildings by a street, a frosty hollow where cold air pools and a bare windy corner, with seven numbered pins

Figure 3. A model garden. South is at the top, so the sunny wall faces up the page.

Warm spots

Cold spots

Zone pushing

Small tricks that help borderline plants through winter.

Wood-chip mulch spread around a young plant
MulchA 2–4 in layer after the ground cools shields roots from deep freezes.
Wind arrows stopped by a row of small conifers
WindbreaksHedges, fences or burlap screens block drying winter wind.
A wooden cold frame with a glass lid over seedlings
Cold framesA glazed box traps daytime warmth around plants.
A potted plant with an arrow pointing into a small house
Move pots inShift containers to a garage, porch or indoors before hard freezes.

5.What zones leave out

A hardiness zone only measures winter cold. Summer heat, frost dates, chill, rain, soil and snow decide just as much.

A glazed ceramic sun

Summer heat: AHS Plant Heat Zones

American Horticultural Society Plant Heat Zone Map: average days per year above 86°F (30°C). Choose a heat zone.

Heat zone 7
On average, 61–90 days a year above 86°F (30°C).

  • A calendar with a snowflake
    Frost datesLast spring and first fall frosts set when to plant and how long the season runs.
  • A pale blue clock
    Chill hoursMany fruit trees need enough winter hours near 32–45°F to flower and fruit.
  • Three raindrops
    Rain and humidityWet winters and humid summers finish off plants that the cold would spare.
  • Three soil layers with a water drop
    Soil and drainageRoots in cold, waterlogged soil rot; good drainage improves winter survival.
  • A mound of snow over green leaves
    Snow coverA steady snow blanket insulates roots; bare frozen ground is much harsher.

6.Practical rules

Read the tag, then pick a plant hardy to your zone or colder.

A plant tag reading zones 5–9

Reading a plant tag

“Zones 5–9” means it survives winters in zones 5 through 9. Low number: the cold limit. High number: the warm limit.

A terracotta pot with a snowflake by its rim

Containers: about 1–2 zones less hardy

Roots in a pot face air temperatures, not soil. Illinois Extension: pick plants hardy two zones colder.

Five zone chips with a green check mark

Choose hardy to your zone or colder

In zone 6b, a 4–8 plant is a safe bet. A 7–10 plant needs a warm spot, a pot or winter protection.

A red map pin

Find your zone

Enter your ZIP code at planthardiness.ars.usda.gov and use the half zone (a or b) for borderline plants.

Tag check

to
A safe bet in the groundZone 6 sits inside zones 5–9, with at least one zone to spare.

Sources and notes

Zones are a starting point: local conditions, variety and care decide what thrives. City zones are for one downtown ZIP code each; plant ranges are typical values, and named varieties can differ.

  1. USDA ARS news release, Nov 15 2023: USDA unveils updated Plant Hardiness Zone Map
  2. USDA ARS Plant Hardiness Zone Map, Map Creation page (planthardiness.ars.usda.gov)
  3. Oregon State University PRISM Climate Group, PHZM (prism.oregonstate.edu/phzm)
  4. American Horticultural Society Plant Heat Zone Map (as reproduced by University of Arizona Extension AZ1673)
  5. NC State Extension Plant Toolbox; Missouri Botanical Garden Plant Finder; Oregon State Landscape Plants
  6. University of Illinois Extension: Overwintering potted plants
  7. Penn State, UGA and WSU Extension microclimate pages
  8. City zones: 2023 PRISM data by ZIP code via phzmapi.org