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molie_gw

New USDA Plant Hardiness Zone Map

molie
12 years ago

What's your reaction to the new Plant Hardiness Zone Map? Has it altered your buying for the next season?

I'm not so convinced even though our weather seems to be changing because I often go down a zone when buying plants, like z5 when purchasing roses.

Molie

Here is a link that might be useful: USDA Zone Map

Comments (18)

  • gardenweed_z6a
    12 years ago

    I always got mixed answers when searching on my ZIP Code--some websites put me at 5b while GardenWeb always showed 6a. Since my weather records supported the Z6a, that's the one I go by. I will plant things that are only hardy to Z6 but I've never tried pushing the envelope with anything for Z7.

    I've got my fingers crossed the Lobelia cardinalis 'Fan Scarlet' I planted last year comes through the winter. I suspect it will considering this mild winter we've had. I've got 'Fan Blue' and 'Fan Salmon' on order from Santa Rosa Gardens which are also rated for Z6.

    Two years ago I did lose a Gaura lindheimeri that was nursery-grown and rated for Z5 but my winter sown gauras all sailed through last winter's extreme weather.

  • NHBabs z4b-5a NH
    12 years ago

    I really like the detail provided in the individual state maps. There's a tongue of colder zone 5a (I think that in the old map it was 4b) that dips down through the center of NH and I never knew if I was included in that. Now I know that I am, which fits my observations. This year as I plan orders I am finding myself willing to spend a bit more on zone 5 plants knowing that they their survival is more probable here than I have expected in the past. Previously I was classified in zone 4b and was willing to try zone 5 plants only if I didn't mind them as annuals (with annual pricing.) Now I am willing to try a few inexpensive zone 6 plants in sheltered spots to see if they will survive a year or two, especially during winters like this one or ones with deep snow to provide shelter.

    I don't think we have gone below 5 degrees this winter, though we also have had virtually no insulation from the snow. What little we've had has turned to ice within days of falling. I am hoping that a few more tender salvias that I usually plant as annuals might have survived this year, though most probably they won't have done so. I do know that I can't count on winters like this every year, though . . .

  • claireplymouth z6b coastal MA
    12 years ago

    The new state map works well for me too. I've always considered my yard to be in zone 6b based on my proximity to the coast and the immediate change in temperature and weather as I head north, south or west (east requires a boat).

    Zipcode searches usually put me in 6A but most of Plymouth is colder than here.

    The new map has me in solid 6b but there's a tongue of zone 7a moving up the coast from the Cape. If they had a zone 6c I'd go for it.

    I'm staying with my usual safe guidelines - plants should be hardy to zone 6 and able to tolerate dry summers and wet winters with minimal snow cover and nasty winds.

    Claire

  • bill_ri_z6b
    12 years ago

    I don't pay strict attention to the zone maps. Obviously, I wouldn't try to grow a zone 9 plant here in zone 6B, but it there are differing zone ratings for a plant at various nurseries/websites, and there is a chance that they will grow here, I will usually try it, provided of course it's a plant I like. There are many microclimates in most gardens, and many factors other than temperature that the USDA map does not take into account. And as I always say, the plants CAN'T READ the zone maps! There are things that are supposed to survive zone 6 that have died, and things that should be zone 7, and they grow like weeds for years. Zone maps are a good guide, but only that and no more. There are far to many other factors to consider. Ultimately I feel that if I like a plant, and it's close to zone 6 hardiness (7A or even 7B), I'll try it. A protected spot is best, but the true test is only by trying.

    {{gwi:5901}}

  • mad_gallica (z5 Eastern NY)
    12 years ago

    Well, we have been moved from 5b to ....

    Wait for it....


    Isn't this exciting?

    Oohhh, the suspense....


    And the winner is....

    We have been moved to ....


    5b

    Yes, that's right. After all the fuss and hoopla, we have been rezoned from 5b to 5b.

    The interesting part is that the interactive map has sprouted a ridge of 5a a few miles to the east of us. But that isn't the same as the valley of 4b/5a that I've been hearing about for as long as we have lived here. That line is still further east.

    So for the foreseeable future, I'll still lay claim to zone 5-ness. We see -15 too often to get complacent about mere 5b-dom.

    BTW, Soap bubbles freeze at -10. Frozen soap bubbles are really cool. They don't pop, but shatter, and the light refractions are really cool.

  • claireplymouth z6b coastal MA
    12 years ago

    Tony Avent's January e-newsletter discusses the making of the new map and the rationale for the changes. He was on the technical review committee.

    Claire

  • bill_ri_z6b
    12 years ago

    Well I guess I disagree with a lot of you, but I wouldn't let a zone map (which is based solely on temperatures and completely ignores other equally important factors) dictate what I should grow. Gardening is fun and interesting, and was always, and still is, an ongoing experiment too. Where's the challenge if we don't expand our plant base by trying new things?

    {{gwi:5901}}

  • mad_gallica (z5 Eastern NY)
    12 years ago

    The thing is, that from experience, I know that those 'other equally important factors' are *NOT* in my favor. The things labelled 'zone 6 - zone 5 with careful siting', *WILL* bite the dust sooner rather than later.

    And I'm not the only one around here with that experience. I am geographically quite close to zone 6. Cooperative Extension actively discourages people who live there from planting zone 6 plants. Their line is 'zone 6, but plant for zone 5'. It comes down to knowing your microclimates, and what you can get away with.

  • NHBabs z4b-5a NH
    12 years ago

    MG - what a fun tidbit about soap bubbles! I'll have to try that next time it gets cold, preferably with a kid or 3 around to get excited about it.

  • molie
    Original Author
    12 years ago

    MG I also loved that tip about frozen soap bubbles & will 'file it away' for next winter when my grandchildren will most likely be here (and I'm guessing that winter will be more normally cold). Sounds like a fun mini-experiment to do with them.

  • rockman50
    12 years ago

    I don't take these subtle changes/zone shifts very seriously. The zone maps work for the "Big Picture"....yes....you can't grow Mangos in New England. But claiming that a subtle shift in zone suddenly changes what you can or can't grow or what will thrive or not thrive is foolhardy. On that scale, the zone maps are deficient because they only consider the lowest temperature typically recorded during winter. It doesn't consider the duration and frequency of cold temperatures, wind, whether or not the ground is frozen, snow cover, etc. I have said it before and I will say it again: Zone 7a in south coast New England is NOT the same as zone 7a in northern Alabama. It just isn't. If your zone shifts a small amount perhaps you will see a similarly small change in plant performance....meaning 2 leaves survive winter on that marginal plant instead of just 1! But does it suddenly thrive? Nope.

  • bill_ri_z6b
    12 years ago

    Rockman, looking at my previous post in this thread, it seems we are in agreement. USDA zones don't take all the factors into account, and therefore are only rough guides. I have "zone 7" plants that are doing fine, and have seen "zone 6" or even "zone 5" plants that have struggled, or even died. As long as I don't expect to grow mangoes in New England, as you said, I try what I think I can get away with. There are successes and there are failures, but always a learning experience.

    {{gwi:5901}}

  • claireplymouth z6b coastal MA
    12 years ago

    And then there's the wet winter issue. I tried to grow Agastache rupestris, which I adore, and it survived one winter planted on a slope but didn't make it through the next winter. It's hardy to zone 5 but apparently not with wet feet. Dry summers I have (usually), but not dry winters.

    I'm not willing to treat a perennial as an annual so I won't try that one again.

    Claire

  • rockman50
    12 years ago

    Yes..soil moisture during winter is a very interesting factor. I have always wondered how palm trees and other subtropical vegetation can be grown with reasonably success in places like Albuquerque where it can get very very cold in winter---like below zero. But they have dry well drained soils which apparently really does boost the survival chances of marginal plants.

  • bill_ri_z6b
    12 years ago

    Albuquerque is zone 7A, but the same zones out west, particularly in the southwest, are just not the same as here in New England. For one thing, they get more sunshine hours because they are further south, and many more days of sunshine, because they don't get the storm systems and clouds very often the way we do. And finally, they get many milder breaks between the cold weather periods, again presumably because they are further south (means more hours of sunlight) and get so many more days of sunshine anyway. That means that it gets drier, and also the ground seldom freezes, and even if it does, it's not for long.

    St. George, UT and Cape Cod, MA are both zone 7A. I've been to St. George, and there are palm trees all over town. And not just the hardy ones like Windmill palms, which are zone 7 anyway, but even the Washingtonias. But I am sure that there is no way you will see them all over the Cape! It's the same zone, but a totally different climate. That's why I say zones are a guide, but ultimately it's up to each of us to try (or not try) to grow whatever we want, within reason. So no coconuts in Providence, but I do have camellias and Clerodendron. Not supposed to grow here, but the plants apparently haven't been told that, so they are fine!

    {{gwi:5901}}

  • Joan2600
    10 years ago

    I'm a newbie, so please forgive my ignorance.
    I understand that my zone is 7B, per the hardiness zone map. I live near the Rio Grande in the valley in Albuquerque, NM. I also have a well on my property which gives (as I am told) pretty iron-rich water.

    Given these specifications, how should I begin to choose plants for various locations in my garden?

    Needless to say for those who know New Mexico, there's LOTS of sun. I'm not entirely sure that a portion of an 10' wide area enclosed by 6 foot walls to the east and north and a house to the west (with a pergola to boot) is semi-shade.

    Where and how do I begin?

    Thanks for any and all suggestions.

  • pixie_lou
    10 years ago

    joan - you may want to try this question on the Southwestern Gardening forum. This is the New England Gardening forum. Our climate is very different than yours. And even our members in zone 7 are in a moister, cooler zone than you.

    Here is a link that might be useful: Southwestern Gardening

  • NHBabs z4b-5a NH
    10 years ago

    Another good resource would be the perennials forum which may have folks from the SW and is quite active, and also a nursery website that's in your area, High Country gardens and carries many plants for the southwest. www.highcountrygardens.com/

    Here is a link that might be useful: perennials forum