How to Read and Use the AHS Heat Zone Map for Gardening

Most gardeners are intimate with the USDA plant hardiness geographical zone map , which represents cold hardiness . But cold-blooded hardiness only indicates one aspect of a plant ’s favourite conditions . Its power to tolerate heat energy is equally important . You might have picture heat zones listed along with hardiness zone on your plant labels , but what do they mean ? The follow information will help you better infer and use this valuable horticulture tool .

The Best Plants for Areas with Extreme Heat

bakshis for Keeping plant Alive Through a Heat Wave

8 Inspired Drought - Tolerant Plant Combinations for a Water - Wise Landscape

AHS heat zone map

The American Horticultural Society ’s rut zone mathematical function can help you determine how plant will cope with heat .

This mathematical function is dissever into 12 zone to indicate the modal number of day in a class when the temperature develop above 86 ° F . Since this single-valued function was developed for the United States , it does not cover Canada , but gardeners in southern Canada can utilize the northernmost areas of the map as an close together guide .

What are heat zones?

Heat zones are specific area on the American Horticulture Society ’s heat zone function . This map categorizes regions of the United States based on the ordinary act of “ heat days ” per year — that is , days with temperature above 86˚F — which is a critical limen for plant physiology , since most plants begin to tolerate stress at this degree . Each heat zona indicates a range of the number of heat twenty-four hour period in each region .

How do you read the heat zone map?

The color - dupe mapping indicates warmth zone across the United States between 1 ( no heat twenty-four hours ) and 12 ( 210 or more heat energy daylight ) . detect the people of color of your region on the mapping and match it to the key argue your heating geographical zone , then liken that to found tolerances . Each industrial plant has a range of heat geographical zone that it can tolerate , which is similar to how plants can thrive in a range of hardiness zone . While not all reservoir presently betoken a plant ’s heat - geographical zone range , the system is becoming more wide adopted , and internet site , catalogs , and plant recording label are starting to name this information more readily .

How do you select plants based on heat zones?

Because this map was created in 1997 , your heat geographical zone is likely somewhat hot than indicated on the map . For the great success , select plants that are well within your region ’s warmth geographical zone . If you live at the hot extreme of a plant ’s range , you might consider providing good afternoon refinement or another form of protection to modify the produce surroundings .

Kim Toscano is a horticulturist , entomologist , garden designer , author , and pictorial designer . She antecedently hostedOklahoma horticulture , a hebdomadary television programme produced by the Oklahoma Cooperative Extension Service .

Fine Gardening urge Products

mass medium Nut Wizard 14 " for English Walnuts , Chestnuts , Golf Balls

Fine horticulture receives a commission for items purchased through links on this site , including Amazon Associates and other affiliate advertising programs .

Fiskars Garden Tool Caddy with Removable Small Tool Storage for Indoor and Outdoor Gardening Use , Made with Recycled Plastic

Get our latest summit , how - to article , and instructional videos send to your inbox .

Signing you up …

What Is My Gardening Zone?

Has Your Zone Changed?

Join Fine Gardening for a free engage live webinar feature Dr. Janna Beckerman , a renowned industrial plant diagnostician as well as prof emerita at Purdue University and the ornamentals technical coach …

When I spotted a particular sand dollar sign cactus ( Astrophytum asterias ) at the Philadelphia Flower Show a few calendar month ago , I know I was in problem . With a delicious coloring radiation pattern …

When we only prioritize plants we want over plant life our landscape painting needs , each season is filled with a never - stop listing of chores : pruning , pinch , lachrymation , treating , amending , and fertilizing , with …

Video

Touring an Eco-friendly, Shady Backyard Retreat

You must be careful when you go in the backyard of garden graphic designer Jeff Epping — not because you ’re likely to travel on something , but because you might be dive - flunk by a pair …

4 Midsummer Favorites From a Plant Breeder’s Garden

Episode 181: Plants You Can’t Kill

Episode 180: Plants with Big, Bold Foliage

4 Steps to Remove Invasive Plants in Your Yard

All Access members get more

sign up up for afree trialand get access to ALL our regional content , plus the rest period of the fellow member - only content program library .

Start Free Trial

Get perfect site accession to expert advice , regional mental object , and more , plus the print magazine .

Start your FREE tryout

Already a member?access

merican Horticultural Society heat zone map

AMERICAN HORTICULTURAL SOCIETY, 7931 East Boulevard Drive, Alexandria, VA 22308 703-768-5700, fax 703-768-8700.Coordinated by:Dr. H. Marc Cathey, President Emeritus.Compiled by:Meteorological Evaluation Services Co., Inc.Underwriting by:Monrovia Nursery Company, Horticultural Research Institute of the American Nursery and Landscape Association, Goldsmith Seed Company, Time-Life Inc., September 1997 Copyright ©1997 by the American Horticultural Society

AHS heat zone map