Defining a zone

[ruskinPalms]

Hello,

I was just reading the worst freezes thead and ran accross Darnell's Dictum. Anyway, what plants define a USDA zone? What should I be looking for? How can you know how old the defining plants are? For example, I live in the boonies and there are very few interesting palms planted. I guess the farmers that owned the land here previously were not interested in Royal palms, Coconuts etc. However, there are large "groves" of bananas around with fruit, large Ficus elastica trees - the largest being about 50' in height just accross the street in an old home's front yard. Several other smaller 'weeping fig' trees maybe to the largest being 30-40' in height. There are clumps of Dypsis lutescens with fully trunked canes to 15-20' high - some even out in the open. Everyone has plumeria near their houses in the older neighborhoods - but only a couple are large maybe 10-15' high. Ones in people's open front yards were indeed fried by frost this last year and did not come back. Bananas did seem to have 50% fried foliage but all came back. Papayas near homes where untouched, but in the open were melted. I have actually been able to find 2 coconut palms growing in the old neighborhood next to this new development - not big - one is not trunking yet and the other looks to have only a 2' or so of trunk. Anyway, what other zone defining plants should I be looking for and at what size? What would could I safely call my zone based upon what I have described? I currently go with the USDA and call it 9B.

[Dave-Vero]

Distributions of native plant species seldom coincide with the USDA (1990) zones.  An exception would be saw palmetto

http://www.efloras.org/object_page.aspx?ob...1018&flora_id=1

Not far from the 8a-8b line.

[spockvr6]

(ruskinPalms @ Aug. 18 2006,15:29)

QUOTE

For example, I live in the boonies and there are very few interesting palms planted. I guess the farmers that owned the land here previously were not interested in Royal palms, Coconuts etc.

Bill-

I hate to be the ultimate realist, but Ray Hernandez hasnt chimed in yet, so I guess Ill take the role  

Please do not take any of this as more than what I have gathered over time by listening to others and doing my own research (including lots of driving around the Tampa Bay area with my camera).

---pessimist on---

It is unlikely that the folks of old in your area had no interest in such palms.  What is more likely is that they have perished.

If one takes a drive around the known warm areas of Tampa Bay (such as the downtown St. Pete area), one can see certain tender palms growing in fairly large quantities.   This can be no accident.  

Now, if one leaves that immediate area, such palm sightings decrease in number, and do so quite quickly and notably.  Again, this can be no coincidence.  It is doubtful that the people that live but a few miles from this prime area have no interest, or less interest, in growing tender palms.  What it much more likely is that they have tried and failed.

Now, to take it to hard numbers, lets look at the temperatures seen on 2/14/06.  Albert Whitted AP in downtown St. Pete only dropped to 46F.  I believe you reported about 31-32F in your area.

Are you seeing a pattern developing here?

My area is no different than yours and these same tender palms will eventually perish without manual intervention.  If that were not the case, my street would look like downtown St. Pete, but it doesnt.  Short of relatively new plantings of tender items, the long term palms are Sabals, Queens and Washingtonias.  

---pessimist off---

[ruskinPalms]

(spockvr6 @ Aug. 18 2006,21:48)

QUOTE

(ruskinPalms @ Aug. 18 2006,15:29)

QUOTE

For example, I live in the boonies and there are very few interesting palms planted. I guess the farmers that owned the land here previously were not interested in Royal palms, Coconuts etc.

Bill-

I hate to be the ultimate realist, but Ray Hernandez hasnt chimed in yet, so I guess Ill take the role  

Please do not take any of this as more than what I have gathered over time by listening to others and doing my own research (including lots of driving around the Tampa Bay area with my camera).

---pessimist on---

It is unlikely that the folks of old in your area had no interest in such palms.  What is more likely is that they have perished.

If one takes a drive around the known warm areas of Tampa Bay (such as the downtown St. Pete area), one can see certain tender palms growing in fairly large quantities.   This can be no accident.  

Now, if one leaves that immediate area, such palm sightings decrease in number, and do so quite quickly and notably.  Again, this can be no coincidence.  It is doubtful that the people that live but a few miles from this prime area have no interest, or less interest, in growing tender palms.  What it much more likely is that they have tried and failed.

Now, to take it to hard numbers, lets look at the temperatures seen on 2/14/06.  Albert Whitted AP in downtown St. Pete only dropped to 46F.  I believe you reported about 31-32F in your area.

Are you seeing a pattern developing here?

My area is no different than yours and these same tender palms will eventually perish without manual intervention.  If that were not the case, my street would look like downtown St. Pete, but it doesnt.  Short of relatively new plantings of tender items, the long term palms are Sabals, Queens and Washingtonias.  

---pessimist off---

Yep Larry, I know......I am banking on the retention pond in the back and the fact that I have planted stuff close to the house. It just surprises me to see some large ficus trees, everything else I see here could have grown in the last 2 to 6 years. I really just wondered if I was missing other zone indicator species that might be planted around here.

Bill

P.S. there are some incredible Queen palms around here. They even seem to have naturalized in areas.

[Dave-Vero]

Queen palms are indeed known to have naturalized in Florida, and there's some concern that they could become pests.  All of which is  a bit surprising when you consider that homeowners so often have problems with nutritent deficiencies.

I suspect that big, healthy clumps of Everglades palm (Acoelorraphe) would be a good sign of favorable microclimate in Daytona Beach.

[spockvr6]

Bill-

I too have been trying to determine good "indicator" plants.  Coconuts seem to more or less be THE palm to determine a solid Zone 10 area IMO.  Who in his right mind does NOT want one of these beuaties in their yard if there is a snowball's chance that it will grow?

But, its gotten harder to do even this as many people are bringing in good sized palms these days.  So, Ill sometimes wonder if I am getting tricked when I see something  a Coconut with 10 ft of trunk.  Did the owner grow it from a nut....or was it brought in a few months ago off of a trailer!??!  Obviously, there is a big difference if one is looking to use that palm as an indicator.  However, Ive even gone so far as to ask the owners about their palms (if they happen to be outside when I drive by) and the the palms history.  9 times out of 10 the Coconuts that are long term are the ones within literal sight of the Gulf.

[spockvr6]

Heres another good solid Zone 10 indication....a street lined like this.

These are ancient and are located in Palma Sola very close to the Gulf in Bradenton.  Even some of these bear witness to past freezes with visually damaged trunks.

[Walt]

It's Darnall's Dictum! Not Darnell (LOL. The story of my life, the "a" always gets changed to an "e").

Anyway, Darnall's Dictum asserts it's not just what palms, plants, etc., one finds, but their size.

I can find tender palms and plants all over my county, but in the coldest areas they are small from getting frozen back. In the warm areas the same plants are far larger.

Many tropical trees/shrubs are truncated from getting their tops frozen off.

Again, the USDA classifies most of Highlands County as zone 9a. Ironically, the 9b area is all in the boondocks, but S.E. part of county.

When you find Hibiscus tiliaceus this size, you can bet your bottom dollar you are not in zone 9a:

by waltcat100

Surely this isn't a zone 9a Ficus elastica:

by waltcat100

Ficus benghalensis of this size dictates that it's zone isn't 9a:

by waltcat100

Plumeria of this stature contradicts a zone 9a rating (and this one is not on a lake, but in town):

by waltcat100

So again, it's not the plants per se, it's how big they are. If the plants are of mature size (like the ones above), then it's safe to say they've stood the test of time and are growing in higher zone than assigned by the USDA, unless, however, someone just planted them at a mature size.

[cryptobionic]

Those USDA zone ratings are meant to be very general, especially in regard to tropicals. Most of us know the miracle of microclimtes, Florida is full of them, man-made or not. I swear that my driveway on it's highest point, exposed to the north winds, borders on a 8b, while there's a patch of my property that's a wannabe 10a. As much as I rely upon my little microclimates,  the indicator plants for my growing zone aren't tropical, but those blessed Azaleas, which consistently and reliably bloom 2 weeks later than those in Orlando every year, even though I'm only 30 miles WNW of that town.  

Larry, is this the same pessimist who grows Pritchardia and Areca? Ha

[Alan_Tampa]

Mango, Ficus species, MANGO , avacado (not always, depends on type) royal poinciana, MANGO

Alan

[spockvr6]

Alan-

Just how hardy are Mangos?

I ask as I have seen quite a few large ones around my area that are dripping with fruit and I know they have seen 20's yet still persist.

[spockvr6]

The same goes for Royal Poinciana.  

I am quite sure this tree has also seen 20's.

[spockvr6]

(cryptobionic @ Aug. 22 2006,02:49)

QUOTE

Larry, is this the same pessimist who grows Pritchardia and Areca? Ha

Well....I guess calling myself a pessimist as I did above is not totally accurate.

I suspect "realist" would be more appropropriate!

When one closely looks at weather data, one is hard pressed to ignore it!  And 2003 was not all that long ago when it was in the upper 20's with brisk winds EVERYWHERE in central FL.  I recall walking my dogs that night and it was not fun!

And.....as far as the Areca and Prichardia....I am a hopeful "realist" thanks to manual protective measures

[BobbyinNY]

Here's what I have to say about "Zone Issues"..............

[Dave-Vero]

spockvr6,

That Royal-lined street in Palma Sola is impressive.  Vero Beach suffered too many casualties in the 1980s freezes to have anything similar.  Yet we have full-sized, healthy Delonix regia.  And we have healthy old mango trees, not to mention monster Ficus trees.

[spockvr6]

Dave-

The Palma Sola area of Bradenton is beautiful!

My aunt/uncle live down there and when I visit I am always amazed at what is growing there.   It is obvious that this area is, dare I say it....immune to really bad freezes, as palms like this wouldnt still be standing.   Royals grow in nearly every yard down there in the same manner as Queens do for the rest of us.

There are also absolutely massive Banyans in this area that I feel rival those of South Florida in size.  There are also huge Shaving Brush Trees, Powder Puff Trees and Tabebuia caraiba.

Another thing that indicates that this area is warm is the fact that I saw numerous examples of Ficus aurea strangling out Sabals.

Even the common stuff like Dypsis lutescens just grows flat out better looking down there as they dont get setback due to extreme cold.

[spockvr6]

Heres one I could hardly believe.....the tree doing this sidewalk damage was a Ficus benjamina!

Although there are some good sized ones in my parts and I know Ficus are capable of such damage, but I have certainly never seen them of this mass in my area.  

[Walt]

Larry,

Your photos are a ringing endorsment/testament to Darnall's Dictum!

Mature plants, like the superb examples in your photos, define the actual zone ratings, regardless of what the USDA might say!

[spockvr6]

Walt-

Youll laugh, but "Darnall's Dictum" is exactly what goes through my head every time I go down there

[Alan_Tampa]

Anything west of 41 south of the skyway looks like that, once upon a time lychee was grown and mango too, in commercial groves in Bradenton (sarasota's ghetto) That F. benny is a shrub, coconuts still there pre-62 if old timers aren't full of crap.  

A big thick trunked mango is dollars to donuts a better indicator that a weed fast Delonix as to climate, one outside of a commercial grove.   Found some monsters (mango) in the Ybor area, as well as a coconut or two of some size, in an area where gardening is not likely a priority.

Alan

[spockvr6]

Alan - What temp strikes the fatal blow to most mangos?

[Walt]

My University of Florida info says a mature mango can take down to about 25 degrees for short duration. Of course, that would probably totally defoliate the tree, at least, IMO.

I've always wanted to ask the owner of this tree what the coldest it has taken and what kind of damage it incurred:

by waltcat100

I did talk to the owner of this mango tree and he told me the tree was frozen down to 10 feet, mostly only trunk left from the two day Dec. 1989 freeze.:

by waltcat100

This mango tree was grown from a pit, planted in 1937, and has survived all the freeze heretofore. The man that planted this tree is now in his late 80s and there was an article in my local paper about it. Subsequently, I drove up to Sebring, Florida, and took some photos of the tree:

by waltcat100

Trunk of above mango tree:

by waltcat100

[SubTropicRay]

Go south young man!!  We're all doomed!!!  This coming winter will be 1989 plus.  Enough doom and gloom yet?  Just kidding but can't disagree with what I've been reading.  Unfortunately, it's only a matter of time.

[BobbyinNY]

Go south young man!!  We're all doomed!!!  This coming winter will be 1989 plus.  Enough doom and gloom yet?  Just kidding but can't disagree with what I've been reading.  Unfortunately, it's only a matter of time.

Oh, c'mon Ray..... Don't scare me.... If you get an 89 winter than I'm gonna be in Antartica ..... and Cari will throw me out of the house because My electric bill will be over $1000/month :( :(

[BobbyinNY]

Go south young man!!  We're all doomed!!!  This coming winter will be 1989 plus.  Enough doom and gloom yet?  Just kidding but can't disagree with what I've been reading.  Unfortunately, it's only a matter of time.

Oh, c'mon Ray..... Don't scare me.... If you get an 89 winter than I'm gonna be in Antartica ..... and Cari will throw me out of the house because My electric bill will be over $1000/month :( :(

[BobbyinNY]

Go south young man!!  We're all doomed!!!  This coming winter will be 1989 plus.  Enough doom and gloom yet?  Just kidding but can't disagree with what I've been reading.  Unfortunately, it's only a matter of time.

Oh, c'mon Ray..... Don't scare me.... If you get an 89 winter than I'm gonna be in Antartica ..... and Cari will throw me out of the house because My electric bill will be over $1000/month :( :(

[NBTX11]

Want my opinion on USDA zone maps.  The 1990 zone map is FLAT OUT wrong and too conservative.  It was based on too short of time over an abnormally cold period.  I base this on the fact that 1) Any long term climactic study will validate, in the eastern US at least, that average temperatures are higher than the 1990 USDA zone map. 2) Any study of recent weather will validate this map is incorrect. 3) Both the 2003 draft map and 2004 arbor day map indicate different information.  4) Whether we want to admit it or not, global warminng appears to have added some heat over the past 40 to 50 years.  Yet people still refer to the outdated 1990 map.  For an example, the usda map shows San Antonio as barely 8b.  If you look at the long term stats the average 56 year winter low is 22.2F, a mid level 9a and probably 5-7 degrees warmer than the 1990 map.  We have had approximately ONE 8b winter in the last approximately FIFTEEN years.  Some areas in the eastern US are actually averaging a full 10 to 12 degrees warmer than this map, or between 1 to 2 full zones, if you compare the data.  Do the math.  Bottom line, you have to do the climactic data research if you want an accurate picture or get an extremely conservative picture in the 1990 USDA map.  If you went by this map you couldn't grow anything.

[Alan_Tampa]

Sorry Larry for the delay in a response to the mango death by cold question, mangoes have been known to come back from 25F - sometimes and usually big trees 4" diameter branches min, smaller trees get killed to some point near the ground, if lucky above the graft.  A tree with a 1 foot diameter or more trunk is a good indicator that the area has been more or less stable and warm enough for a mango to get some size to it. (15 years or so, in a yard with marginal care, well taken care of trees are a crap shoot and need a case analysis to be useful.)

Hope this is no more confusing that Darnall's Dictum, no name yet for this diagnostic tool.  Also, must be a little off your nut to understand.  I figure anyone who puts socks on his palms or ships queen palms from Florida to the tundra should have few problems with this system.  

Alan

[Alan_Tampa]

Take the zone map and throw it out the window, or into the fireplace or ignore it.  Once you know the area you live or an area of study the zone map is USELESS and a WASTE of your time.  Accurate or not the weather is the weather - it changes.  Climate cannot be defined by the major swings or the calm periods alone, it is IMPOSSIBLE to predict what may happen, and what has happened has inadequate data over time to be anything other than a guide.

Take the weather like you take your boss at work : a jackass who you can either tolerate or ignore.  If your garden is wiped out by cold, cry, break some stuff, smoke something fun - and start again.  Better dynamic than stagnant.  (wait till winter is done before the starting over) Also, learn from the events, note what lived, died as expected or the surprises that for me are the key to making a new rule to MY liking.  

Alan

[cryptobionic]

Alan, that has to be the most wise and refreshing post I've read in a while...

[BobbyinNY]

We have had approximately ONE 8b winter in the last approximately FIFTEEN years.  Some areas in the eastern US are actually averaging a full 10 to 12 degrees warmer than this map, or between 1 to 2 full zones, if you compare the data.  Do the math.  Bottom line, you have to do the climactic data research if you want an accurate picture or get an extremely conservative picture in the 1990 USDA map.  If you went by this map you couldn't grow anything.

Jim,

that's absolutely correct.  I noticed it especially to be true in my area.. The coldest temp I measured last year in my yard during Jan/Fef was 15f - one time only. The AVERAGE low was between 25-30f with alot of nights around 40f and some around 20f.

[NBTX11]

(BobbyinNY @ Aug. 25 2006,08:48)

QUOTE

We have had approximately ONE 8b winter in the last approximately FIFTEEN years.  Some areas in the eastern US are actually averaging a full 10 to 12 degrees warmer than this map, or between 1 to 2 full zones, if you compare the data.  Do the math.  Bottom line, you have to do the climactic data research if you want an accurate picture or get an extremely conservative picture in the 1990 USDA map.  If you went by this map you couldn't grow anything.

Jim,

that's absolutely correct.  I noticed it especially to be true in my area.. The coldest temp I measured last year in my yard during Jan/Fef was 15f - one time only. The AVERAGE low was between 25-30f with alot of nights around 40f and some around 20f.

Bobby, if the 1990 Usda map was correct you should be getting down to near 0F NEARLY EVERY YEAR.  At least 50 percent of the time because it is supposed to be an average.  50% of the time warmer and 50% actually colder.  Which for you would mean 50% of your winters should be BELOW ZERO Fahrenhiet, if this map were correct.  Don't get me started on this map.  I just grow whatever I feel like.  If it ever gets killed, oh well, I will start again with that species.

[spockvr6]

This topic got me interested so I did a little digging on the temps at JFK Airport.  This airport is smack dab on the water, so the readings there might be indicative of what is seen on other parts of Long Island that are similarly situated.

The USDA maps must be quite a bit off if they say it should be down to 0F half the time.  I just checked the data for the past 20 years and had to go back to 1985 to find a single reading below 0F.

2006 - 14F

2005 - 6F

2004 - 1F

2003 - 7F

2002 - 19F

2001 - 16F

2000 - N/A

1999 - 10F

1998 - 15F

1997 - 5F

1996 - 17F

1995 - N/A

1994 - N/A

1993 - 7F

1992 - 12F

1991 - 10F

1990 - 9F

1989 - 8F

1988 - 4F

1987 - 7F

1986 - 7F

1985 - -4F

If the average of these lows is taken (excluding the three years where data was not available), one gets 9F, or USDA Zone 7b.

[spockvr6]

(BobbyinNY @ Aug. 25 2006,08:48)

QUOTE

that's absolutely correct.  I noticed it especially to be true in my area.. The coldest temp I measured last year in my yard during Jan/Fef was 15f - one time only. The AVERAGE low was between 25-30f with alot of nights around 40f and some around 20f.

I think your yard and JFK seem to track closely.

I just checked their data for this past winter and found--

Average Dec 2005 Low - 29F

Average Jan 2006 Low - 32F

Average Feb 2006 Low - 27F

Average Mar 2006 Low - 34F

I am not sure if this is to be expected every year though?

[spockvr6]

The other thing that I constantly have to remind myself is that averages do not generally define what one can grow.  Its the extreme events that are the definers.

If averages were the biggest concern, I would have Lipstick Palms lining my driveway

[spockvr6]

(syersj @ Aug. 24 2006,23:51)

QUOTE

Want my opinion on USDA zone maps.  The 1990 zone map is FLAT OUT wrong and too conservative.   If you went by this map you couldn't grow anything.

I have to agree.....this map has my little plot near the border of 9a!

Yet, one can count using only the fingers on their hands the number of times that the historical records (Tampa AP) dating back to 1900 show where the record low for a given date was less than a 9b value.

[Dave-Vero]

Here's an interesting bit of journalism.  Global warming at work?

http://jscms.jrn.columbia.edu/cns/2006-04-...illhite-zonemap

What grows naturally in Florida and what you can grow in an agricultural/horticultural setting are both very strongly affected by the dry winter with rare but extreme cold snaps, thanks to North America's lack of mountain ranges running from east to west.  There's some reason to believe that Florida was less bothered by such extreme cold during the ice ages.  The continental ice sheet was so high that cold air didn't move across it.

Mangroves suffered terribly during the 1980s and so did strangler figs.

[NBTX11]

(spockvr6 @ Aug. 25 2006,10:46)

QUOTE

(syersj @ Aug. 24 2006,23:51)

QUOTE

Want my opinion on USDA zone maps.  The 1990 zone map is FLAT OUT wrong and too conservative.   If you went by this map you couldn't grow anything.

I have to agree.....this map has my little plot near the border of 9a!

Yet, one can count using only the fingers on their hands the number of times that the historical records (Tampa AP) dating back to 1900 show where the record low for a given date was less than a 9b value.

Exactly, San Antonio has actually been closer to 9b than barely 8b shown on the map, in recent years.  I'm not claiming we're 9b, but it sure isn't zone 8 either.  Last 4 winters has averaged 25F for a low.  This is only a short snapshot, but you take ANY snapshot, short, long, whatever, and the 1990 map is too conservative.  Having said that, I fully realize the record lows have gotten as low as single digits a couple times and yes it could happen again.

[NBTX11]

(spockvr6 @ Aug. 25 2006,10:25)

QUOTE

This topic got me interested so I did a little digging on the temps at JFK Airport.  This airport is smack dab on the water, so the readings there might be indicative of what is seen on other parts of Long Island that are similarly situated.

The USDA maps must be quite a bit off if they say it should be down to 0F half the time.  I just checked the data for the past 20 years and had to go back to 1985 to find a single reading below 0F.

2006 - 14F

2005 - 6F

2004 - 1F

2003 - 7F

2002 - 19F

2001 - 16F

2000 - N/A

1999 - 10F

1998 - 15F

1997 - 5F

1996 - 17F

1995 - N/A

1994 - N/A

1993 - 7F

1992 - 12F

1991 - 10F

1990 - 9F

1989 - 8F

1988 - 4F

1987 - 7F

1986 - 7F

1985 - -4F

If the average of these lows is taken (excluding the three years where data was not available), one gets 9F, or USDA Zone 7b.

If you take the average since 1990, it is 10.57, borderline 8a last 16 years.

[BobbyinNY]

WOW...

that's excellent, Larry........ It's amazing that, for being as far north as we are, we're alot warmer than alot of the inland south (thank god for water moderating the temps). So, if we stay like we did last year, we'll eventually become a solid zone 8a... not too bad..... But mother nature has a way of throwing a wrench into everything....  We can only wait and see what this year has to bring.