Do you have it away what growing geographical zone you ’re in ? Or what that even means ? Contrary to pop notion , USDA hardiness zone arenota skillful indicator of what you could or can not grow . Your zone can tell you one matter only — and lie with what that is will help you choose the right flora for your climate .
Find your USDA zone
Zipcode data is provided by the PRISM Climate Group at Oregon State University . Not every US zipcode is part of this dataset , so if nothing happens when you enter your zipcode , adjudicate the next close zipcode in your townspeople .
Your growing zone tells you one thing
The condition “ growing zone , ” “ USDA geographical zone , ” “ gardening geographical zone , ” and “ planting geographical zone ” all touch to hardiness ratings from the USDA Plant Hardiness Zone Map ( PHZM ) , which divides North America into 13 growing zone base on their average low temperature in winter .
Each zona is 10 ° F warmer ( or colder ) than the next zone , and each zone is further divide into “ a ” and “ b ” half geographical zone ( in 5 ° increments ) to give a more exact reading of temperature variations .
Plant hardiness zones aid farmers , gardener , and landscapers determine which perennials are likely to flourish in their climate . The lower the number , the greater the dusty tolerance .
For model , a plant that ’s stalwart to zone 6 can handle a winter low of 0 ° F to -10 ° F , while a zona 5 plant is adapted to hold up temperatures of -10 ° F to -20 ° fluorine . If we practise down even more , plant life in zone 6a should tolerate lows of -5 ° F to -10 ° F , while plants in geographical zone 6b should tolerate 0 ° F to 5 ° F .
zone 10 and above include tropic and subtropical mood such as Southern California , South Florida , Hawaii , Puerto Rico , and parts of Texas and Arizona , which rarely or never see a frost .
Here ’s the complete temperature chain for each hardiness zona , according to the PHZM :
Your growing zone tells you what will survive winter in your orbit . Let ’s say you want toadd some recurrent herbs to your garden . You blame up a rosemary and see that it ’s unfearing to zones 8 and 9 . If you go in zone 7 , it ’s unlikely to make it through a typical wintertime unless you pot it up and overwinter it indoors . You need to choose a hardy variety ( like Arp rosemary ) or a hardier herbaceous plant ( like thyme ) , or treat the rosemary as an annual herb .
When shopping for plants , you might come across labels with a spacious grasp of hardiness zones , such as geographical zone 3 to 8 . That means the plant will do well in all those zone , but will shin in warmer climates . An good example would be manypopular fall - planted efflorescence bulbs(like daffodil and tulip ) , which want inhuman temperatures to stimulate blooming in spring .
That ’s really all your growing zona can severalize you .
What a growing zone CAN’T tell you
unluckily , there ’s elbow room more a growing zona can not secern you when it come to planting . Your zona ca n’t say you …
… How long you might experience extremely cold weather
Your hardiness zona does n’t really suggest how often or how long you may expect freezing temperature . Many frost - resistant plants can withstand abbreviated freezes , specially under frost covers or an insulate layer of blow . However , these same plants will die if freezing temperatures persist for several days or week .
… When it’s time to plant in spring (or fall)
Your growing zone ca n’t tell you when it ’s secure to plant in spring or when the first frost is expect in decline . Even within the same zone , two unlike cities can have frost dates that are calendar month apart !
Take , for example , Pittsburgh , PA , which falls in zone 6b and has an look last frost engagement of April 24 . Where I be in Bend , OR ( also zone 6b ) , our last frost is n’t until June 26 !
Pittsburgh ’s first frost falls around October 14 , while in Bend , we can expect our first frost around September 7 — a full month to begin with . That ’s a huge difference in the number of frost - free days between the two cities .
Quick tip
If you ’re look for a reliable chart that tells you when you should sow seeds or place out transplantation , usemy interactive pecker to make a personalized planting calendar , based on your actual Robert Lee Frost dates .
… What your microclimate is like
Even though I be in zone 6b , I ’m in a much cold microclimate than the rest of Bend ( ordinarily 5 ° fluorine to 10 ° F colder in winter ) . I ’m also in a dry , mellow desert part and do n’t have the benefit of protective snow natural covering like cold zones get . Because of that , I turn over my “ true ” zone to be 5 , and only buy perennials that are hardy to geographical zone 5 or below .
As I refer in my other post ongrowing food in wintertime without a glasshouse , cold temperatures are not the only thing that impress whether your plants will live ; winter dehydration plays a large role .
… What vegetables you can grow
Your hardiness zone ca n’t tell you the sort of crops that willactuallydo well in your mood .
Let ’s apply Portland , OR , and Houston , TX , as examples here ( both in geographical zone 9 ) . gardener in Portland can grow pelf through the conclusion of June , when the average highs are around 76 ° degree Fahrenheit . ( They can even keep lettuce going all summer with a mo of shade and strategic succession planting . ) Houston , however , experiences highschool of 76 ° degree Fahrenheit by April , which entail lettuce is easily grown through the winter months there .
Related : Try theseheat - resistant lettuce varieties if you live in a warmer zone
What about okra ? Zone 9 should be warm enough to farm this passion - loving crop , right ? ( I had a friend in Houston who once told me they produce two things well : beef and lady’s-finger ! )
While it ’s true that lady’s-finger thrives in the hot Texan sun , it ’s not well adapted to Western Oregon ’s cool , cloudy summers and lower night temperatures . So in this instance — despite okratechnicallybeing capable to last zone 9 — it is n’t productive inallzone 9 regions .
… Whether your plants can survive summer in your area
The USDA Plant Hardiness Zone Map focuses on the median coldest temperatures , but does n’t say anything about the average hottest temperature in a given geographical zone .
Take the Portland and Houston example above . Despite both of these city being in zone 9 , they haveverydifferent mood , specially in summertime . The mean high in Portland in August is 80 ° F and the David Low is 58 ° atomic number 9 . In compare , Houston ’s ordinary high in August is 91 ° F and the low gear is 76 ° F .
Notice how Houston ’s low temp is nearly 20 ° higher than Portland ’s blue temporary ? Wild , proper ? ! So a plant that would thrive over the summer in Portland would believably struggle in Houston ’s scorch heating plant .
Frequently asked questions
In the USDA Plant Hardiness Zone Map , “ a ” is inhuman than “ b. ” The scale begins at 1a for the coldest zone , with 1b being 5 ° heater . Each letter represent another 5 ° of difference as you move down the scale to geographical zone 13b .
Yes , a plant that is n’t repeated to your zona can still be grow as an annual ( or pot up and moved indoors in wintertime ) .
No , Sunset Climate Zones are a unlike set of clime zona maps that apply only to the westerly United States . These maps divide Washington , Oregon , California , Idaho , Wyoming , Arizona , Utah , Colorado , New Mexico , and Texas into 17 zones ( plus some half zones ) based on not only winter low temperatures , but also summertime gamey temperatures , humidity , rain , flatus , and duration of produce seasons .
TheSunset Climate Zone Mapsare produced by Sunset Magazine and tend to give a more complete picture of what the year - round of drinks growing clime is like in a particular western area .
The Canadian regime release its own plant life hardiness zone map . While Canada uses a similar system of number and letters to argue temperature ranges , each zona is determined by a different set of conditions variable quantity than what the USDA zona map is based on . Here ’s a templet to help youconvert between US and Canadian plant hardiness zones .
For a more a detailed look at how growing zones can deviate in your province , rule the corresponding map below . I ’ve included 54 USDA hardiness zone map for the United States and choose US districts and territories . you could press each map to take in a big version on theUSDA website .
Alabama
USDA zona 7b through 9b are represent in Alabama .
Alaska
USDA zones 1a through 8b are represented in Alaska .
Arizona
USDA zones 5b through 10a are represented in Arizona .
Arkansas
USDA zone 7a through 8b are represented in Arkansas .
California (North)
USDA zone 5a through 10a are represented in Northern California .
California (South)
USDA zone 5a through 11a are represented in Southern California .
Colorado
USDA zone 3b through 7b are represented in Colorado .
Connecticut
USDA zones 6a through 7b are present in Connecticut .
Delaware
USDA zone 7a and 8a are constitute in Delaware .
District of Columbia
USDA zones 5b through 8a are represented in the District of Columbia .
Florida
USDA zones 8b through 11b are represented in Florida .
Georgia
USDA geographical zone 6a through 9b are represented in Georgia .
Hawaii
USDA zones 8b through 13a are represent in Hawaii .
Idaho
USDA zones 3b through 7b are represented in Idaho .
Illinois
USDA zone 5a through 7b are represent in Illinois .
Indiana
USDA zones 5b through 7a are represented in Indiana .
Iowa
USDA zone 4b through 6a are represented in Iowa .
Kansas
USDA zones 5b through 7a are stage in Kansas .
Kentucky
USDA zones 6b through 7a are represent in Kentucky .
Louisiana
USDA zone 8b through 10b are represented in Louisiana .
Maine
USDA zones 3b through 7a are represented in Maine .
Maryland
USDA zones 5b through 8a are represented in Maryland .
Massachusetts
USDA zone 5a through 7b are represented in Massachusetts .
Michigan
USDA zones 4a through 6b are represented in Michigan .
Minnesota
USDA zone 3a through 5a are be in Minnesota .
Mississippi
USDA zona 7b through 9b are stand for in Mississippi .
Missouri
USDA zones 5b through 8a are represent in Missouri .
Montana
USDA zones 3a through 6b are symbolize in Montana .
Nebraska
USDA zones 4a through 6a are represented in Nebraska .
Nevada
USDA zones 4a through 10a are comprise in Nevada .
New Hampshire
USDA zone 3b through 6b are represented in New Hampshire .
New Jersey
USDA zones 6b through 8a are represented in New Jersey .
New Mexico
USDA zones 5a through 8b are represented in New Mexico .
New York
USDA zones 4a through 7b are represent in New York .
North Carolina
USDA zones 6a through 9a are represented in North Carolina .
North Dakota
USDA zones 3a through 4b are represented in North Dakota .
Ohio
USDA zone 5b through 7a are represent in Ohio .
Oklahoma
USDA zones 6b through 8a are typify in Oklahoma .
Oregon
USDA zones 5a through 10a are represented in Oregon .
Pennsylvania
USDA zone 5b through 8a are represented in Pennsylvania .
Puerto Rico
USDA zones 11b through 13b are represented in Puerto Rico .
Rhode Island
USDA zone 6a through 7b are represented in Rhode Island .
South Carolina
USDA zone 7b through 9b are correspond in South Carolina .
South Dakota
USDA zones 4a through 5b are stand for in South Dakota .
Tennessee
USDA zones 6a through 8a are lay out in Tennessee .
Texas (East)
USDA zones 7b through 10b are represented in East Texas .
Texas (West)
USDA zones 6b through 9b are represented in West Texas .
Utah
USDA zones 4a through 9a are represent in Utah .
Vermont
USDA zones 4a through 6a are represented in Vermont .
Virginia
USDA zones 5b through 8b are represent in Virginia .
Washington
USDA zones 4a through 9b are represented in Washington .
West Virginia
USDA geographical zone 5b through 7a are represented in West Virginia .
Wisconsin
USDA zones 3b through 6a are represented in Wisconsin .
Wyoming
USDA zones 3b through 6a are represented in Wyoming .
