Can someone enlighten me...?

[miss_thenorth]

Okay, maybe ths is my 'blondeness' showing through, but I don't quite get the American and Canadian plant hardiness zones.

I was reading SilkieChicken's thread about growing watermelons, and I'm wondering if my climate is cooler than hers, how it differs etc...

I have grown watermelons, and they got to be a good size, and they were delicious. Will this info help her? Is my location 'cooler' than hers? Maybe I will have some free time this afternoon to look it up thoroughly, but for now, --I am just confused..... Can anyone enlighten me?

It might also help you to know that I have never been anywhere. The most I've ever travelled was up north when we lived near Timmins, ON, and as for the states, I've been to Cedar Point once and Traverse City once. So I basically live in a bubble.

 

[patandchickens]

The USDA zones are based on minimum winter temperatures.

The Environment Canada zones are based on that plus some other things (number of frostfree days, and consistency of winter snowfall, I *think*)

Somewhat coincidentally, the two systems are off by 1 in *most* (not all) parts of Canada, so that your Canadian zone number is most often one less tnan your American zone.

Example: I am Canadian zone 5b (canadian zones are divided into a and b halves, american aren't, but don't worry about it) which pretty much equals USDA zone 4.

Of course that;s just an average for a regionand your property might differ as you get to know it - most of my yard has more of a zone 3-4 climate, but for perennials in my front flowerbed, in sort of a suntrap with lotsa snowdrifts, it's more like a zone 6-7 microclimate.

Steve has posted a link (somewhere around here) to find your US zone for places in the States. In Canada, pick up most any seed catalog or decent book , or try www.nlwis-snite1.agr.gc.ca/plant00/index.phtml (or google 'canadian plant hardiness zones" for other sites that may be friendlier if your browser has trouble with that)

Hope this helps,

Pat

 

[patandchickens]

adding:

the watermelon thing doesn't depend much on zone, it depends on # growing days per season and how hot it gets (both absolutely, and in degree-days). Ontario summers may (or may not?) be shorter than in Wash state but I am pretty certain ours are hotter and sunnier, which the melons need to set and ripen.

Zones pertain more to winter-hardiness.

Pat

 

[patandchickens]

me again Here is a more informative and quicker loading link

http://sis.agr.gc.ca/cansis/nsdb/climate/hardiness/intro.html

click on the 2000 zones map thumbnail for a usable size view.


-P

 

[Reinbeau]

Actually American zones are divided into a and b, they have been for quite some time. I'm in 6a here, just 20 miles south of me is 6b and then in the furthest southeast corner it's up to 7a.

 

[miss_thenorth]

Thanks, Pat. I guess my brain fart occurred b/c I was thinking plant hardiness zones, when I actually should have been thinking along the lines of growing degree days.

And thanks for the links--I'll check them out...

 

[Queen of the Lilliputians]

Actually American zones are divided into a and b, they have been for quite some time. I'm in 6a here, just 20 miles south of me is 6b and then in the furthest southeast corner it's up to 7a.

Thanks, I was just about to post this!

It's interesting to hear there is so much added to the Canadian zones. I guess our zones are pretty straightforward (but probably not the best indicator of what is grow-able). For instance, head North and the numbers get smaller. Head south, and they get larger. (that's an oversimplification, of course, but is the basic principal). With Canadian zones, does it mean you can have a zone 4 smack dab in the middle of a zone 6, based on rainfall, etc?

Just curious

Meghan

 

[patandchickens]

You will pretty much never get a 'skipped' zone, because climate pretty much varies in a continual not stepwise fashion. There are most certainly places where you can go from zone 4 to zone 6 in an incredibly short distance, but there's zone 5 in between, know what I mean? (And you get that in the US as well as Canadian zones - basically in the mountains out West).

Canadian zones are, in my humble opinion and actually I spent the first 37 years of my life in the US so it's not like I'm automatically prejudiced , rather more sensible than US zones. US zones are, as far as I know, pretty much just based on min winter temps, whereas Canadian ones purport to also take other things into account:

"In 1967, Agriculture Canada scientists created a plant hardiness map using Canadian plant survival data and a wider range of climatic variables, including minimum winter temperatures, length of the frost-free period, summer rainfall, maximum temperatures, snow cover, January rainfall and maximum wind speed.

Natural Resources Canada's Canadian Forest Service scientists have now updated the plant hardiness zones using the same variables and more recent climate data (1961-90). They have used modern climate mapping techniques and incorporated the effect of elevation. The new map indicates that there have been changes in the hardiness zones that are generally consistent with what is known about climate change. These changes are most pronounced in western Canada." (from the link I posted earlier)

But you know what, zones are STILL a pretty vague and unreliable thing, even in Canada, and not just because of site-specific microclimates either. For instance even though there are zone 4 locations in BC, Saskatchewan and the Atlantic provinces, you are just NOT always going to be able to grow the same things well in all 3 places.

<shrug>

(Edited to add: what we REALLY need is a RELIABLE COMPREHENSIVE map, based on lots and lots of data, of where *each kind of plant* will and won't grow well. There are attempts underway in Canada to construct such things, I would assume probably also in the US, but AFAIK we're still a long long ways away from really being able to look up a database and say "ah, I see that *this* plant should be happy in my region but this *other* one tends to croak". But, if it ever happens, BOY that would be nice, and would largely render the whole zone thing obsolete.)


Pat, glad to have been corrected about US 'a' and 'b' zones, and having NO idea WHAT she was thinking when she wrote that, especially since Anne's signature says "zone 6b" plain as day every time you look at her posts