New USDA Map Soon?

[SoLando]

Anyone know when the new USDA cold hardiness zone map will come out? I've seen a few articles about them making a new one a while ago, but haven't heard anything else on the matter.

Anyone want to guess at what the changes will be? How far north would 11 go on Florida, or 10?

[Exotic Life]

Hi Solando,

Do you know if this only will be for America ? Or also Europa ?

[Bilbo]

I cant see the point of changing things but then I may be speaking from a personal and particular viewpoint ie. the UK which is notoriously difficult to predict.

Basically we just give things a try and wait to see . . .

it aint scientific but it seems to work for us.

Regards

Bilbo

(OK Im Jon but I still cant log on as myself despite desperate attempts to re-register as myself!)

Regards

Juan

PS. looking forward to 1st Oct (DR) and have just collected my tickets from Thomas Cook - not the cheapest to be sure - but 100% reliable.

[Dave-Vero]

USDA seems to be working in-house on an interactive tool that will allow users to compare factors beyond winter cold.

[spockvr6]

Although I like looking at colorful maps......a thermometer in ones own yard is still far better

[Bilbo]

I certainly agree Larry but over here in weirdsville even that thermo cant be relied on!

Honest mate this Island group is hell on sea weather wise.

Oh well at least it teaches us UK guys to learn to deal with widely differing climatic conditions.

That makes us guys versatile and I (and buddies) can design and plant anywhere in the world with no problemo.

Regardez

Juan

(Jon)

[elHoagie]

(Bilbo @ Sep. 08 2006,06:47)

QUOTE

Bilbo

(OK Im Jon but I still cant log on as myself despite desperate attempts to re-register as myself!)

I'd stick with Bilbo.  I think everyone on the board has forgotten Jon by now anyway......

Jack

PS - just kidding, and I'll see you in a couple weeks in the DR  

[SubTropicRay]

Hi Jen,

From one central Floridian to another, forget the maps.  Look at what is planted around you and making it through the winters.  That is and always will be your best gauge.  

Ray

[spockvr6]

(Ray, Tampa @ Sep. 08 2006,14:47)

QUOTE

Hi Jen,

From one central Floridian to another, forget the maps.  Look at what is planted around you and making it through the winters.  That is and always will be your best gauge.  

Ray

Darnalls Dictum!

[Exotic Life]

If i look around me, i don't see any palm tree In some gardens you see trachycarpus, but every year you see mopre people dat buy palm tree's end diffrent species. So i think the people must looking to me ...

I see here quercus,Salix etc.

[ruskinPalms]

I think this is a link to a very detailed version of the American Horticultural Society's draft version of the hardiness zones that the USDA did not like:

http://www.landmarkgardens.com/USDA%20.....03.pdf

[spockvr6]

I thought that new map was actually pretty good (maybe a bit too optimistic in some cases), but I thought the elimination of the a/b subdesignations was a step backwards.

[Dave-Vero]

ruskinpalms,

That is indeed the withdrawn map.  I'm surprised it's posted on the web--AHS was very careful about copyright, and they took it down after USDA rejected it.  

This unofficial hardiness zone map resembles the AHS map, and may be based on the same data:  www.arborday.org

[SunnyFl]

Dave, thanks for that link.  I used to have it on my old computer - when it broke, I lost the site.  Why did the USDA reject it?  Is the data unreliable?

I entered my zip code and it came back 10.

For central FL, I agree with Ray - look around and see what's growing in your own neighborhood.   Zones 9b and 10a are very mixed throughout the Tampa Bay area, and I would guess elsewhere too.

St. Pete used to be rated as 9b, but in my microclime, if I plant any plants which have a rating only up to 9b, they decline within a year.   Plants that have a rating up through 10 have a much higher success rate.  

A lot of what you see here is a minimum of zone 10.

Is the USDA really going to drop the a/b designations?  Makes no sense.  There really IS a difference between what flourishes in Zone 10a vs. 10b.

[Neofolis]

It would be nice to have zone indicators that take into account more than just winter lows, like in the case of the UK lack of reliable summer heat or arizona and the likes with excessive summer heat.  That said, it would probably over complicate things and make defining zones for specific palms very difficult.  Trying the palm still seems the most reliable option and if it fails, keep trying it until one doesn't.

[spockvr6]

(SunnyFl @ Sep. 11 2006,06:33)

QUOTE

I entered my zip code and it came back 10.

Ive tried every zipcode in the area that I can think of and every one comes back noted as zone "9-10"!

Thats pretty insightful!  LOL.

[spockvr6]

(SunnyFl @ Sep. 11 2006,06:33)

QUOTE

Why did the USDA reject it?  Is the data unreliable?.

I have heard it speculated that the USDA did not like the data as it appeared to show too much climate change in too short of a period ???  You know....all that government secret agenda type stuff......

[spockvr6]

(SunnyFl @ Sep. 11 2006,06:33)

QUOTE

A lot of what you see here is a minimum of zone 10.

Yeah....weve all gotten pretty brazen here in the last decade!

I think the landscape staples are still Zone 8/9 items, but there sure are alot more Zone 10 "rated" palms/plants making up the landscape.

From what I have learned from the folks Ive become friendly with at the local nursery (who have been there for over 50 years).....things are cyclical.  They told me that after the 1962 freeze and the 1980's freezes that they couldnt even give away what are pretty much common landscape items today (things like Hibiscus, etc).  Everyone got wiped out so badly, that they were gunshy for a few years to touch anything that was not freeze hardy.  But, then their memories of the events faded, they realized they really did like those plants they lost, and these more tender plants came back into demand.

And so the cycle continues today.

[Dave-Vero]

Some of my neighbors still remember cutting down their hibiscuses in 1989.  

A lesson from the native vegetation of Florida, the Bahamas, and the West Indies is that it's an uncertain weather environment, with quite a few disturbances including hurricanes, freezes, drought.  In Florida, fires are a regular staple in the pinelands and less-frequent-but-inevitable in scrub (like California chaparral).  In many cases, the vegetation is always at some stage of recovery from the last disturbance.

So it's advisible to

1.  Make good use of natives.  Live oaks, Simpson stoppers, Hercules club, spider lilies, needle palms--all sorts of good stuff.

2.  Use tropicals that will come back after a freeze.  

3.  When using tender palms, prefer species that grow fast, look good when young, and can easily be removed after a bad freeze.  And buy asap after a freeze!

4.  Think about wind resistance.  Many palms are good.  Livistona and Sabal may be the best, based on John Dowe's work-in-progress

5.  Use vegetation to shelter your house or business from wind.  Live oaks work wonders.  

6.  After a freeze, look busy in the yard.  This might encourage the neighbors to not chain-saw all their landscaping.

[SunnyFl]

(spockvr6 @ Sep. 11 2006,08:48)

QUOTE

(SunnyFl @ Sep. 11 2006,06:33)

QUOTE

Why did the USDA reject it?  Is the data unreliable?.

I have heard it speculated that the USDA did not like the data as it appeared to show too much climate change in too short of a period ???  You know....all that government secret agenda type stuff......

That actually would be believable.  When the official report on global warming came out, it was widely reported - in credible news sources - that certain "deletions" were made by the administration.  They didn't like what it said.   ???

Okay, so if there's a problem developing, don't let's fix it - let's cover it up!

Now we're seeing reports that the permafrost is melting, releasing methane, and it's called a "time-bomb."

And the arctic ice is melting, and if it changes the salinity of the Atlantic, there's also the danger the Gulfstream current could be altered, or just gradually stop, turning Europe's and the UK's climate much colder.

[SunnyFl]

(Dave-Vero @ Sep. 11 2006,13:16)

QUOTE

Some of my neighbors still remember cutting down their hibiscuses in 1989.  

Really - cutting them down?  We had a bit of that, too, in Pinellas Park - which is like a cold sink for the higher elevation on its southern border (which is where I now live).  Anyway, at my Pinellas Park home, I had a number of hibiscus.  I didn't pull them out, and by spring, they were coming back from the roots.

At my current house, the freeze damage was much less.  Elevation does make a difference.

Dave, your list is great.  I do think it's very important to consider wind resistance - trees and shrubs can protect homes from wind.  Live oaks are good - sand live oaks are better for small lots.  (But laurel & water oaks are bad,bad,bad - shortlived, shallow-rooted and fall easily).

Here's a problem with natives - sometimes it's hard to find the larger ones.  I've been looking around for a good-size chionanthus (native to Pinellas) and can't find one.  Nice to see more stoppers showing up, though.  Conocarpus is an excellent native - why isn't it on the approved list?

[spockvr6]

(SunnyFl @ Sep. 12 2006,07:05)

QUOTE

Really - cutting them down?  We had a bit of that, too, in Pinellas Park - which is like a cold sink for the higher elevation on its southern border (which is where I now live).  Anyway, at my Pinellas Park home, I had a number of hibiscus.  I didn't pull them out, and by spring, they were coming back from the roots.

At my current house, the freeze damage was much less.  Elevation does make a difference.

Do you recall what the actual temps were at each location?

[alex_7b]

Let's not meander down the Global Warming path just yet, heh?

The biggest problem with the USDA maps are the short timespans that they're based upon. If they would use 25 or 30 years of data (which they have already), they would capture the 1sigma data as well as the hot and cold outliers in the cycles.

[spockvr6]

(alex_7b @ Sep. 12 2006,13:12)

QUOTE

Let's not meander down the Global Warming path just yet, heh?

I think that perhaps, regardless of reality, that they might be worried about perception.

[spockvr6]

(alex_7b @ Sep. 12 2006,13:12)

QUOTE

If they would use 25 or 30 years of data (which they have already), they would capture the 1sigma data as well as the hot and cold outliers in the cycles.

I have no idea why they dont do just that.

For some locations, they have 100 years worth of data.  Who knows how accurate some of the ancient data is, but certainly the last 25 or so years worth has to be reliable.

In the meantime, I am just logging temps in my own yard and calling it a day

[Dave-Vero]

Thanks, SunnyFl.  

I suspect Chionanthus (fringe trees) might have a reputation (probably undeserved) for not transplanting easily.  Check with native plant nurseries.  www.afnn.org.  They do grow quickly if given a good spot and they'll like dry sites.  You can find them growing in the wild around Tampa Bay.  

Conocarpus might not be on a local "approved" list because of sensitivities about planting a mangrove on uplands, or out of concern over hardiness.  

Here's some info on the 1962 freeze at www.citrusindustry.net (pdf):

AND COLD IT WAS!

It was a blowing cold that kept the air mixed. High ground temperatures were no better than low ground temperatures. Temperatures recorded at key locations the morning of Dec. 13, with hours below 28° in parentheses, were: McIntosh 16° (15); Citra 16° (13); Mims 21° (10); Umatilla 16° (15); Howey-in-the-Hills 20° (11); Haines City 20° (11); Avon Park 22° (7); Lake Placid 24° (7); Wauchula 21° (9); Fellsmere 22 ° (7); Vero Beach 24° (5); LaBelle 22.4° (5).

Northerly winds of 15-20 miles per hour until after mid-day on Dec. 13 provided a continuous supply of cold air for 24-36 hours after the front passed in the north and central districts. Fortunately, temperatures moderated slightly on Dec. 14 as the cold air failed to push the entire length of the peninsula, resulting in less damage in the Indian River District and in southwest Florida.  

***

The Vero Beach airport reported a low of 23 degrees on December 24, 1989.  John Kennedy reported 18 the same morning, not far away.  www.plantapalm.com

By the way, the Simpson stopper, Myrcianthes fragrans, wasn't hurt in the Vero Beach area by the 1989 freeze.  www.plantcreations.com

[spockvr6]

(Dave-Vero @ Sep. 12 2006,17:40)

QUOTE

It was a blowing cold that kept the air mixed. High ground temperatures were no better than low ground temperatures.

This is the problem with the dang advective fronts.  The two big things one can have on their side (elevation and water proximity) are largely nullified.

[spockvr6]

Great article link Dave!

I love those historical pieces.  Got any more?

[Dave-Vero]

spockvr6, That info was the result of some lucky googling.  It turned out that the citrus industry magazine had only a half-dozen archival pieces online.  I was really surprised to find the info on the Dodgers' Holman Stadium (which, by the way, is a direct precursor to Chavez Ravine--they liked the NYC Parks guy who built Holman, so they hired him to create the big stadium.  

Here's an interesting Florida State University take on cold and heat hardiness mapping:

cold hardiness jpg image

and here's an explanation of the maps: www.coaps.fsu.edu/climate_center/

[NBTX11]

(Dave-Vero @ Sep. 12 2006,22:24)

QUOTE

spockvr6, That info was the result of some lucky googling.  It turned out that the citrus industry magazine had only a half-dozen archival pieces online.  I was really surprised to find the info on the Dodgers' Holman Stadium (which, by the way, is a direct precursor to Chavez Ravine--they liked the NYC Parks guy who built Holman, so they hired him to create the big stadium.  

Here's an interesting Florida State University take on cold and heat hardiness mapping:

cold hardiness jpg image

and here's an explanation of the maps: www.coaps.fsu.edu/climate_center/

That's an interesting map.  It looks like it is basically in line with the 2003 draft map and 2004 arbor day map.

I've seen an old zone map from about 1960, 2003 map, 2004 map and they are all in line, the only one out of whack which most people refer to is the 1990 map.

[spockvr6]

Great maps!

In a generalized sense, I think that these are probably reasonably close to the truth.  Of course, and as noted in their explanation of how the maps were created, "Within each zone there are many places with microclimates that fit within warmer or colder zones. "  

The best part is that the data used was from 1981 to 1995.  So, this includes the averaging in of all those nasty 1980's cold fronts, which will bring the zonal averages down and likely make them a bit conservative since those type of events dont happen all the time.  

Still, I wonder what these maps would look like if ALL available data were used (i.e. 50-100 years worth in some cases)?

[SubTropicRay]

I like what these maps do for south Tampa's Interbay peninsula.

[Dave-Vero]

The first/last freeze probability maps that are also provided may be more useful in predicting palm survival www.coaps.fsu.edu--Agriculture

Maybe we need a map of overall freeze probability.  I bet it already exists.

[spockvr6]

(Dave-Vero @ Sep. 13 2006,13:38)

QUOTE

Maybe we need a map of overall freeze probability.  I bet it already exists.

The SERCC has something that is close...but not quite.  They call it their "Freeze Free Probability" and it is based on data which is 100 years worth in some cases.

They have charts which show the probabilities of the number of days between certain temperature thresholds occuring.  If the number of days gets to 365, then it doesnt necessarily mean that freezes dont occur, only that they are spaced out by more than a year.  

Heres an example for the Tampa AP.

This plot states that there is a 70% chance that the number of days between the last Spring 32F temp and the first fall 32F temp will be greater than 365 days.  

If the temperature threshold is raised to 36F, the probability for the same scenario to occur drops to about 30%.

So, I think one can use these plots as a decent rule of thumb.  Ive made the further assumption that, in the case of the Tampa AP data, that the 70% probability mentioned above likely more or less means that there is a 30% chance of a freeze occuring in any given winter.

[spockvr6]

Heres another example for Jacksonville AP.

I take this plot to mean (via the rule of thumb mentioned above) that a freeze is going to happen every year at this location, but that theres a 40% chance the temp will be above 28F.

I know that going 365 days between freezing events doesnt mean a site didnt freeze during a certain year (as the previous winter's freeze could have been early in the year and the next freeze later in the next winter, so that they were more than 365 days apart), but I suspect that since these plots use such long term data that the rule of thumb might be semi-reasonable to apply.

[NBTX11]

Looks like inland South Florida between Ft. Myers and Boca Raton has the most heat with an impressive 200+ days of 85 degree weather or higher.  From what I remember living in FL was that inland locations like Lakeland could be significantly hotter in summer with plenty of 95F temps and even close to 100F on occasion.

[Dave-Vero]

spockvr6, I suspect you've found the most useful predictor of palm hardiness for Florida.  http://www.sercc.com/climateinfo/historica...torical_fl.html

Pick a site and check the "'Freeze Free' Probabilities"  If it doesn't have a line showing the 28 degree probability, you're in a good spot (like St Petersburg).

[spockvr6]

Dave-

You are right in that this is the best info I have found as of yet after a few years of searching.  Its the most expansive Ive found as well since they use all available data.

The St. Pete plot is certainly revealing and the local foliage matches the plot.  They dont even have a 32F line on the chart!  And, theres an 80% chance of not dropping below 36F.

[spockvr6]

While we are at it.....over your way in Vero looks pretty dang good as well

[SoLando]

http://cirrus.dnr.state.sc.us/cgi-bin/serc...FrezD.pl?fl6628

So, let me make sure I'm understanding this chart (this one is quite different than most I've seen..ha). This means that there's a 40% chance that our days will be above 36 degrees and an 80% chance that our days will be above 32? Or is it the opposite?