USDA Hardiness Zones — Find Your Zone & Best Plants

Click a zone to jump to its card

coldest — subarctic hottest — tropical

Cold zones

8 zones · 3a-6b

Short seasons, hard winters. The growers who do well up here treat season extension — cold frames, hoop houses, indoor light — as part of the kit, not the upgrade. Plant timing matters more than plant choice.

Zone 3a -40°F to -35°F

last frost May 15

first frost Sep 15

123 frost-free days

subarctic, extreme winters

example cities interior Alaska, far northern Minnesota, northern Maine

See the zone 3a guide Zone 3b -35°F to -30°F

last frost May 10

first frost Sep 20

133 frost-free days

very cold continental

example cities Bemidji MN, northern Maine, parts of upstate NY

See the zone 3b guide Zone 4a -30°F to -25°F

last frost May 5

first frost Sep 25

143 frost-free days

cold continental

example cities Duluth MN, Aroostook ME, northern WI

See the zone 4a guide Zone 4b -25°F to -20°F

last frost May 1

first frost Oct 1

153 frost-free days

cold continental, short season

example cities Minneapolis MN, Burlington VT, Fargo ND

See the zone 4b guide Zone 5a -20°F to -15°F

last frost Apr 25

first frost Oct 5

163 frost-free days

cold-winter humid continental

example cities Minneapolis, MN · St. Paul, MN · Anchorage, AK

See the zone 5a guide Zone 5b -15°F to -10°F

last frost Apr 20

first frost Oct 10

173 frost-free days

humid continental, cold winters

example cities Omaha, NE

See the zone 5b guide Zone 6a -10°F to -5°F

last frost Apr 15

first frost Oct 15

183 frost-free days

humid continental, moderate winters

example cities Chicago, IL · Indianapolis, IN · Denver, CO

See the zone 6a guide Zone 6b -5°F to 0°F

last frost Apr 10

first frost Oct 20

193 frost-free days

temperate, four-season

example cities Columbus, OH · Detroit, MI · Kansas City, MO

See the zone 6b guide

Mild zones

6 zones · 7a-9b

The four-season sweet spot — long enough to grow almost anything, cool enough that summer doesn't kill it. The trap is overconfidence. Surprise frosts in May and humid disease pressure in July are the real failure modes.

Zone 7a 0°F to 5°F

last frost Apr 5

first frost Oct 25

203 frost-free days

temperate transition, mild winters

example cities Boston, MA · Louisville, KY · Wichita, KS

See the zone 7a guide Zone 7b 5°F to 10°F

last frost Apr 1

first frost Nov 1

214 frost-free days

humid subtropical, mild winters

example cities New York, NY · Queens, NY · Philadelphia, PA

See the zone 7b guide Zone 8a 10°F to 15°F

last frost Mar 25

first frost Nov 10

230 frost-free days

humid subtropical, warm

example cities Charlotte, NC · Memphis, TN · Atlanta, GA

See the zone 8a guide Zone 8b 15°F to 20°F

last frost Mar 15

first frost Nov 20

250 frost-free days

humid subtropical, hot summers

example cities Dallas, TX · Fort Worth, TX · El Paso, TX

See the zone 8b guide Zone 9a 20°F to 25°F

last frost Mar 1

first frost Nov 30

274 frost-free days

warm subtropical to semi-arid

example cities San Antonio, TX · Austin, TX · Seattle, WA

See the zone 9a guide Zone 9b 25°F to 30°F

last frost Feb 20

first frost Dec 5

288 frost-free days

warm subtropical, long season

example cities Houston, TX · Jacksonville, FL · Las Vegas, NV

See the zone 9b guide

Hot zones

4 zones · 10a-11b

Mild winters, brutal summers. Winter is the real growing season down here — plant lettuce in October, brassicas in November, harvest into spring. Summer is survival mode: shade cloth, fabric pots, twice-daily watering.

Zone 10a 30°F to 35°F

last frost Feb 10

first frost Dec 15

308 frost-free days

hot semi-arid to tropical fringe

example cities Phoenix, AZ · San Jose, CA · Oakland, CA

See the zone 10a guide Zone 10b 35°F to 40°F

last frost Jan 30

first frost Dec 25

329 frost-free days

hot desert / coastal southern

example cities Los Angeles, CA · San Francisco, CA · Long Beach, CA

See the zone 10b guide Zone 11a 40°F to 45°F

last frost no frost

first frost no frost

365 frost-free days

tropical, no killing frost

example cities San Diego, CA · Miami, FL · Hialeah, FL

See the zone 11a guide Zone 11b 45°F to 50°F

last frost no frost

first frost no frost

365 frost-free days

tropical / Hawaiian lowlands

example cities Honolulu HI, Key West FL

See the zone 11b guide

A note on zone boundaries

USDA zones are average annual minimum temperatures — half-bands of 5°F each. They tell you what will survive winter in a typical year, not what will thrive in summer or what's safe in a freak cold snap. Your county extension office has frost dates and pest maps calibrated to your microclimate. Use these guides to plan a season; use local data to save the crop.

The example cities listed on each card are drawn from our MVP city set. Real cities can sit one half-zone off the regional average due to elevation, coastal influence, or urban heat — when in doubt, check your city hub for the local read.

— the Real Food Grower editorial team