skip to main content

New Plant Hardiness Zone Map published today (1/25)

12 years ago

FYI - the USDA posted a new zone map..

http://planthardiness.ars.usda.gov/PHZMWeb/, if you are curious...

Mine is still the same. Yours?

Sort by:Oldest

Comments (27)

kimka
12 years ago
I've been part of the team that developed this version of the map. You can read alot of details about the map at
http://www.ars.usda.gov/is/pr/2012/120125.htm

The official url is

www.planthardiness.ars.usda.gov

KimKa
NancyPlants
12 years ago
well, the new map moved me from zone 5b to 6a.
Did anyone else have changes?
Related Discussions
updated USDA Zone Map today
Q
Comments (22)
Lots of interesting comments here, but to me the salient issues are these: 1) this is a map based on statistical averages. It does not take into account the fact that every piece of ground is subject to the effect of microclimates. Elevation, latitude, topology, soil type, proximity to water, and existing vegetation - even man-made structures - all affect the POSSIBILITY of reaching the temperature parameters that define a particular zone. 2) Weather, and more importantly climate, are complex studies, and subject to variables still poorly understood. It is well known, for instance, that the earth has experienced different cycles of warmer-than-previously and cooler-than-previously, but the cause and timing of those cycles is rarely clear - the effects of a volcano, or a meteoroid hitting the earth can account for some cooler periods, but the cause of many of the cycles is still conjecture. Right now, we seem to be in a warming trend, and many climate-change deniers point to that as evidence that mankinds' influence on the atmosphere has no bearing on the global warming issue - the debate rages on. For the most part, the natural cyclical changes, and to a lesser degree, I believe, global warming, are incremental, they happen over relatively long periods of time, and will not soon affect the likelihood of anyone successfully growing more tender crops on a regular basis. 3) As zeedman points out, and some orchardists clearly grasp, this is a map of winter low temperatures; as such it is most useful in predicting the odds of perennial plant survival, and is of less utility to those who are planning their annual garden. First and last frost dates, precipitation, and wind maps are equally important when a gardener is trying to integrate climate statistics into a coherent garden plan. The gardening activities most immediately concerned with this map are structural ones concerning perennial crop placement, hardscaping, and mulching, and very little to do with the choice of which variety of annual to choose. 4) The best guide to hardiness is the native ecosystem in your specific locale. Being familiar with the native plants, watching for bud formation on local trees, new green growth in the woods, even the activities of wild animals and birds, is often a far more reliable indicator of current weather trends than human predictions based on statistical charts. As mentioned above, these are guidelines, useful for planning purposes, but no guarantee of future performance.
...See More
New USDA Plant Hardiness Zone Map Released
Q
Comments (13)
It surprises me how many people still don't understand the idea behind a climate zone map, including those who should know better. We had an article in our local paper today about the new USDA map (which puts most of Ohio in zone 6). They interviewed a manager at our largest (and best) nursery in central Ohio (which was previously placed on the border between zones 5 and 6 and is now all zone 6). He said he was continuing to tell customers that we are in zone 5, because we're still going to have extreme winters or severe storms from time to time. That's not the point of climate zones, which are determined by the average winter low temperature. If zone 6 gardeners see an wintertime low on average of -5F but are faced every decade or so by a drop to -20F, they are still in zone 6, not the border between zones 4 and 5. A severe cold snap might damage or kill susceptible plants (depending on site, drainage and snow cover) but it doesn't make sense to garden with these extremes in mind. Of course you could play it safe and only use plants that are semi-guaranteed to be rock-hardy in your area, but you'll miss out on a lot of great things. If (for example in my area) you get years of enjoyment from a Nandina or crepe myrtle but it eventually succumbs to a hard winter, you're still ahead of the game.
...See More
New Hardiness Zones!
Q
Comments (18)
The original article I read that wasn't on the one I posted said that the Arbor Society is pushing to have two numbers on a plant, so that people can know which ones will do well in the heat as well as how much cold they can withstand. This makes a tremendous amount of sense to me and is much more informative than just the one number which may be outdated. Buford, sure the climate has always changed and if you look at it over time the ecosystem adjusts. The problem is that some plants and animals die out while others get stronger...all of which takes a lot of years. As gardeners we are just worried about keeping a rose alive for maybe 10 or 20 years, a mere drop in the bucket to the grand scheme of climate change. I want all the info I can get and I NEED all the info I can get. LOL I'm sorry for those who are having a cold spring. It happens and I always feel like I've been cheated.
...See More
Creating a detailed CA plant hardiness map
Q
Comments (16)
I have to agree with Bahia, here. There is a reasonable level of resolution for these maps. Attempting additional "refinement" would only misinform. First of all, consider the questionable validity of the averaging methods being used: static climate maps are made by doing statistical averaging over different study periods (usually 12 years long). Algorithms are then used to interpolate data and draw isotherms between reporting stations. So the sample size is quite small, both in terms of the tiny amount of territory the reporting stations cover and the reach of time in the study period. The USDA map of 1990, therefore, looks different than the 1960 map because, in part, the 1974-1986 examination period used for 1990 did not include many major freeze events in the West. A more accurate way to show an average minimum temperatures map would be as an animation over, say, a 20-year period. That's how climate really is: it's fluid, changing from one year to the next. Think video, not snapshot. It's common to come across pat declarations of hardiness, i.e., "hardy to 28F," but such statements are laughable. Hardiness is not established by winter only. The nature of the growing season, exposure and soil quality have a lot to do with it. A plant hardy to 22F in Palm Springs where summers are hot and winters are dry, might die at 30F in Eureka where summers are cool and winters are wet. Finally, a map is only useful if there is a significant body of literature that will dedicate itself to its use. Sunset may have only its own Western Garden Book going for it, but what a book! After 30 years of using the Sunset WGB, I am increasingly impressed with its accuracy under periodic revision AND...its VALIDITY (the editors understand the limitations of attempts to pigeonhole climate). Many envelope pushers of zone envy along the northern third of the West Coast who have often complained that Sunset was "too conservative" are eating crow after Old Man Winter decimated their marginal plants last year. Climate maps SHOULD be conservative.
...See More
PVick
12 years ago
I went from 6B to 7B.

PV
morz8 - Washington Coast
12 years ago
No, no changes here, I'm still the same 8b....The zone people will look at and assume is warm when we're not :) 70F is a nice summer day, and my snow from last Wednesday followed by ice storm on Thursday is finally gone/melted today.
kqcrna
12 years ago
It moved me from 6A to 6B.

Karen
beatrice_outdoors
12 years ago
I moved from 6a to 6b. It looks like most of the upper east coast of Massachusetts did this.

So far any changes noted here are to a warmer zone. Has anyone been changed to a COLDER zone?
pixie_lou
12 years ago
Last time they changed the map I moved from 5b to 6a. However I still won't plant anything that isn't hardy to zone 5, or preferably to zone 4. Nothing like a freak weather event to take out your favorite perennial.
msmashy
12 years ago
I am now 7a
prvrbs31gal
12 years ago
http://planthardiness.ars.usda.gov/PHZMWeb/InteractiveMap.aspx

If you are 'on the line' you might find the interactive map helpful. Our zip code encompasses such a large area that the zip-code finder came up for me as 7b, but when I zoomed in, I am clearly 8a. Not that it matters much, but it's interesting.
shemeows
12 years ago
I've been moved from 6B to 7B. I had to zoom in to see, since the zip code I'm in encompasses two very distinct areas.
It's interesting to have been moved one whole zone.
fixerupperinnh
12 years ago
I just got the b added to mine.
EZGarden
12 years ago
mine didnt change still too hot here. :)
pixie_lou
12 years ago
Wow - that interactive map is great. Turns out if I lived across the street, I'd be zone 6b! But I still consider myself zone 5.
kimka
12 years ago
Some of the moving to cooler zones include
Pierre, South Dakota from 5A to 4B but the actual average low temp is onlyy -20.2 degrees F which means that a change of two tenths of a degree changed their zone. Grand Portage, Minnesta cooled form 4B to 4A but their actual annual average low temp was -27.9 putting them squarely in the middle of their zone. A lot of cooler zones are also in the Sierra Madres, probably because of the greater accuary of this map.

I can show you similar small changes causing a zone change on the warm side too. Tampa, FL moved from 9B to 10A. But the actual average low temp is 30.4. So the new zone is only by 0.4 degrees.

You can get your actual average low temp as well as your zone and its range from the interactive map by clicking on your location and checking the popup box.

What I'm pointing out is that a zone change can be caused by as little as a tenth of a degree, not 5 degrees.

KimKa
(Truth in advertising--I'm part of the team that designed the new map)
ellenrr
12 years ago
wow. I changed to 7A. frightening evidence of a warming trend.
I used to be 6A, then became 6B.

It's going to take some getting used to to be zone 7.

thanks for this.
DemonsHollowAsylum
12 years ago
Just checked the new map and boy are they wronge for my area.
They say I have gone from 5 to 6b. This year has been a very mild and dry winter but we still had -13 just a week ago and last year durring a normal but very wet winter we had -18. I will stick with what I know about my micro climete and not follow the macro climete scale just to stay on the safe side.
not_a_contessa
12 years ago
This stuff can be really confusing. I used to think I was in zone 6, then the (prior) new map put me in 5, and the seed catalogs had me in 5 also. This new map puts me in 6a. I still plan to use 5 as my guide though, because it can get a lot colder than their temperature guide. I personally think it's better to be more prudent and the only exception would be if you decide to do a "leap of faith" with a particular plant that you desire.
Bamaw
12 years ago
I got moved from 7b to 8a. Don't know what to make of that, because I know our temps are colder than the Dallas area and I WAS going to say Austin, but they've been moved into 8b. Shoot, San Antonio's been moved into 9a! It's ALL different!
User
12 years ago
I'm now in the middle of 6a...I was on the line of 5b and 6a.

Matthew
Indiana.Matt
gardenunusual
12 years ago
Better change my info to 5b. A couple of years ago I can remember being zone 4.
myfamilysfarm
12 years ago
I was an outcast in my area being in 5b with very few acres, while everyone else being in 5a. Now everyone near me is 5b.
daisydawnny
12 years ago
Went from zone 5 to 6a.......this really screws up zone wars.
doubleAmom
12 years ago
They put me in 6a. Still saying 5 for now though!
ladyrose65
12 years ago
I'm still 6B.
caryltoo Z7/SE PA
12 years ago
Moved from 6b to 7. Don't know if it makes much of a difference.
faerygardener z7 CA
12 years ago
I went from 7 to 9A according to the new map(small town, not very populated, mountains so one town is up / colder and one lower elevation and warmer, most maps had been pretty generic). I guess you could say my average winter night temp is in the 20's but I think of USDA 9 as my bay area location and can attest to the fact that a lot of the plants I brought with me cannot handle the winters here. Sunset zones still have me at their 7 which is more useful for me (I have SUCH a shorter growing season here). Our record lows tend to be high single digits to low teens, so I'll probably use that - like others every winter it seems we're hitting a "record low" and I don't want to have to run out and cover plants in a snowstorm.
dfshaw
12 years ago
Moved from 5b to 6a, this winter's acting like 7a - what's a guy to do! Sticking with 5b,

Dean

Related Stories

GARDENING GUIDES Great Design Plant: Paddle Plant

By Annie Thornton

If you're looking for awesomely strange foliage and low care requirements, this succulent is right up your alley

GARDENING GUIDES 9 Clay-Busting Native Flowers for Summer Sun

By Benjamin Vogt / Monarch Gardens

These plants survive and even thrive in tough clay soil east of the Rocky Mountains

PLANTING IDEAS 7 Stunning Plant Combinations for Low-Water Gardens

By Dig Your Garden Landscape Design

Find inspiration in these beautiful drought-tolerant companion plantings

GARDENING GUIDES 6 Plants That Beat Butterfly Bush for the Wildlife Draw

By Benjamin Vogt / Monarch Gardens

It's invasive, a nonnative and a poor insect magnet. Check out these better alternatives to butterfly bush in the garden

PLANTING IDEAS Great Garden Combo: 9 Plants for an Intriguing Entrance

Layer trees, flowers and shrubs around an archway to create the feeling of a year-round doorway to adventure

GARDENING GUIDES 10 Top Native Plants for the U.S. Southeast

By Falon Mihalic

For a low-maintenance and wildlife-friendly landscape, use Southern natives that withstand heat and humidity

PRODUCT PICKS Guest Picks: 20 Gorgeous Perennials to Plant Now

By The Estate of Things

Take advantage of warm spring weather to create a colorful garden with blooming plants, succulents and ornamental grasses

TREES 7 Deer-Resistant Flowering Trees to Plant this Fall

If you live in a neighborhood with roaming deer, consider these beautiful trees that won't tempt hungry guests

GARDENING FOR BUTTERFLIES Great Design Plant: California Fuchsia Brings Color and Hummingbirds

Set this summer perennial up in a dry and sunny spot for blazing orange or red blooms into fall

GARDENING FOR BUTTERFLIES Great Design Plant: Aromatic Aster Keeps on Blooming

By Benjamin Vogt / Monarch Gardens

Tough as nails, drought loving, a deep fall bloomer ... this aster is a champ in sunny gardens

Sponsored

Mary Shipley Interiors

32 Reviews

Columbus OH Premier Interior Designer 10x Best of Houzz