My New Hardiness Zone Map of Texas (Handmade)

[Teegurr]

I thought it was time for Texas to have a new hardiness zone map, so I made one myself. Data is from 1992-2021 NOAA minimums.

*Not completely accurate, but I hope you like it and maybe consider using it (thank you) in the future.

 

 

[Xerarch]

Looks like a pretty solid attempt to me, I'll leave any nitpicking to others

[RedRabbit]

Nice work 

[Xenon]

Lots of red and orange but I'm not complaining 

 

I see some cool botanical illustrations...can we see more of those? 

[Teegurr]

29 minutes ago, Xenon said:

Lots of red and orange but I'm not complaining 

 

I see some cool botanical illustrations...can we see more of those? 

Yeah hopefully that's at least partly accurate. I know for sure I was a little generous with 9b near Eagle Pass. The illustrations are from a book about North American trees. It's really great, but the palm drawings are a little inaccurate.

[Sabal_Louisiana]

That looks about right (hardiness maps are not an exact science anyway( but of course local microclimate should be taken into consideration, especially for urban areas.

For instance both Dallas (Love Field) vs. Austin (Bergstrom) have an average annual minimum of 18f for the past two decades despite Dallas being about 190 miles farther north.

I find it a bit odd that the 9b range makes that little extension to include El Campo, it may be legit but who knows.  And I'm thinking the line b/w 8b and 9a should be nudged a tad to the south to at least Jasper in East Texas.

 

[Teegurr]

5 hours ago, Sabal_Louisiana said:

That looks about right (hardiness maps are not an exact science anyway( but of course local microclimate should be taken into consideration, especially for urban areas.

For instance both Dallas (Love Field) vs. Austin (Bergstrom) have an average annual minimum of 18f for the past two decades despite Dallas being about 190 miles farther north.

I find it a bit odd that the 9b range makes that little extension to include El Campo, it may be legit but who knows.  And I'm thinking the line b/w 8b and 9a should be nudged a tad to the south to at least Jasper in East Texas.

 

El Campo was right at 9a/9b. You may very well be right about Jasper and 8b/9a. I couldn't find any data for Jasper or the surrounding area so I had to wing it.

As for microclimates, I didn't do much. I was a little surprised to find Joe Pool Lake in DFW to be 8a. I also included a spot of 10a in central Houston. 

[Sabal_Louisiana]

Yea, I could see where downtown Houston might barely make it into 10a. NWS data shows the mean annual minimum for Hobby Airport since 2001 or so as 27f. Select locations around the downtown might be a couple of degrees higher per year on average.

6 of 10 years b/w 2011-2020 at Hobby failed to drop below 30f. That's 10a or better inclusive.

However, each of the other 4 years experienced 25 or colder (hard freeze criteria) That's 9b or lower for those years.

Then of course, we had the aberration of 2021.

Now it's anybody's guess what the rest of the 2020s will bring.

[Xenon]

34 minutes ago, Sabal_Louisiana said:

Yea, I could see where downtown Houston might barely make it into 10a. NWS data shows the mean annual minimum for Hobby Airport since 2001 or so as 27f. Select locations around the downtown might be a couple of degrees higher per year on average.

6 of 10 years b/w 2011-2020 at Hobby failed to drop below 30f. That's 10a or better inclusive.

However, each of the other 4 years experienced 25 or colder (hard freeze criteria) That's 9b or lower for those years.

Then of course, we had the aberration of 2021.

Now it's anybody's guess what the rest of the 2020s will bring.

1990-2021 jumps to 28F for Hobby. The warmest parts of central Houston did not see below 24/25F from 1997-2016 (possibly since 1991 too, Hobby only hit 23F in 1996). Warm enough for foxtail palm, majesty palm, pygmy dates etc. 

The immediate southeastern shoreline of Galveston Bay is practically as warm as the island, and actually even warmer than the east end of Galveston Island.

Edited April 29, 2021 by Xenon

[Collectorpalms]

On 4/27/2021 at 12:26 AM, Teegurr said:

I thought it was time for Texas to have a new hardiness zone map, so I made one myself. Data is from 1992-2021 NOAA minimums.

*Not completely accurate, but I hope you like it and maybe consider using it (thank you) in the future.

 

 

Pretty nice. Glad I ignored previous ones, and planted some zone 7 and 8 palms and not all zone 9! The 1980s haunted me. Now I have the scars from 2021 to show it.

[bananaman]

On 4/28/2021 at 10:31 AM, Sabal_Louisiana said:

For instance both Dallas (Love Field) vs. Austin (Bergstrom) have an average annual minimum of 18f for the past two decades despite Dallas being about 190 miles farther north.

Austin Bergstrom is known to be in a cold pocket. The station is in the valley of Onion Creek, where cold air tends to pool. This is a direct quote from the NWS office about it: “This site is located in a low lying area in the drainage basin of the Onion Creek. Because of this, the overnight low temperature in the wintertime under clear skies can sometimes be 10 degrees colder at Austin Bergstrom compared to Austin Camp Mabry. The distance between the ASOS sites is only 10.7 miles.” For the 1991-2020 climate period, Camp Mabry averages 12 freezes a year, while the airport averages 35. It’s probably more due to the topographical effect than anything else. It does show what a difference microclimate factors can cause, though.

[Collectorpalms]

11 hours ago, bananaman said:

Austin Bergstrom is known to be in a cold pocket. The station is in the valley of Onion Creek, where cold air tends to pool. This is a direct quote from the NWS office about it: “This site is located in a low lying area in the drainage basin of the Onion Creek. Because of this, the overnight low temperature in the wintertime under clear skies can sometimes be 10 degrees colder at Austin Bergstrom compared to Austin Camp Mabry. The distance between the ASOS sites is only 10.7 miles.” For the 1991-2020 climate period, Camp Mabry averages 12 freezes a year, while the airport averages 35. It’s probably more due to the topographical effect than anything else. It does show what a difference microclimate factors can cause, though.

It was mostly due to cold air drainage. But I have noticed in the last 10 years, the effects are significantly less now that the airport area is no longer rural.

[necturus]

Looks nice and certainly reflects the data in Houston, but before the freeze it didn't necessarily reflect reality, at least to my eyes. The Greater Houston area != Corpus Christi... not even the immediate water front.

Has anyone visited TAMU Corpus Christi? I am dying to know what happened there. I am expecting the worst but hoping for a microclimate miracle.

[Teegurr]

On 5/7/2021 at 11:25 PM, necturus said:

Looks nice and certainly reflects the data in Houston, but before the freeze it didn't necessarily reflect reality, at least to my eyes. The Greater Houston area != Corpus Christi... not even the immediate water front.

Has anyone visited TAMU Corpus Christi? I am dying to know what happened there. I am expecting the worst but hoping for a microclimate miracle.

Are you saying Houston's temps are about the same as Corpus, or different? Because they are both technically 9b, Corpus is just a bit warmer 9b, as coconuts have been tried with some success there.

[necturus]

11 hours ago, Teegurr said:

Are you saying Houston's temps are about the same as Corpus, or different? Because they are both technically 9b, Corpus is just a bit warmer 9b, as coconuts have been tried with some success there.

Corpus is more of a Florida 9B. They can grow 10A stuff much longer and better than most of Houston. Houston is 9B on paper but more like Florida 9A. I guess it’s high end vs low end 9B.

[Xenon]

Downtown Corpus and within a short distance from the bayfront (especially the southern shore of CC Bay) are both easily zone 10a going by averages. If anyone's curious, check the weather data for the Naval Air Station. 

[NBTX11]

On 4/28/2021 at 10:31 AM, Sabal_Louisiana said:

That looks about right (hardiness maps are not an exact science anyway( but of course local microclimate should be taken into consideration, especially for urban areas.

For instance both Dallas (Love Field) vs. Austin (Bergstrom) have an average annual minimum of 18f for the past two decades despite Dallas being about 190 miles farther north.

I find it a bit odd that the 9b range makes that little extension to include El Campo, it may be legit but who knows.  And I'm thinking the line b/w 8b and 9a should be nudged a tad to the south to at least Jasper in East Texas.

 

Yeah but in true reality, it’s night and day between Dallas and Austin. 
There are huge old 50 plus year old Washingtonia Filifera and Sabal Palmettos and Mexicana all over Austin. There are none in Dallas (or very few if any). 

[NBTX11]

Should there be a small dot over downtown San Antonio making it a 9b, the Riverwalk in particular. 

[Austinpalm]

On 5/7/2021 at 11:25 PM, necturus said:

Looks nice and certainly reflects the data in Houston, but before the freeze it didn't necessarily reflect reality, at least to my eyes. The Greater Houston area != Corpus Christi... not even the immediate water front.

Has anyone visited TAMU Corpus Christi? I am dying to know what happened there. I am expecting the worst but hoping for a microclimate miracle.

I was there in late March for a very quick trip. What I did notice was that all the black mangrove in Oso bay were fried.  I'm sure some will return from the roots, but in my mind it got very cold if it was lower than 23F (approximate hardiness of black mangrove) out in the bay. I would expect it was at least 5 degree F colder on land, but I could be wrong. I did see many W. robusta with crown collapse.  I'm sure a few will survive, but I expect the Corpus Christi's skyline will be palmy significantly differently going forward.

[necturus]

2 minutes ago, Austinpalm said:

I was there in late March for a very quick trip. What I did notice was that all the black mangrove in Oso bay were fried.  I'm sure some will return from the roots, but in my mind it got very cold if it was lower than 23F (approximate hardiness of black mangrove) out in the bay. I would expect it was at least 5 degree F colder on land, but I could be wrong. I did see many W. robusta with crown collapse.  I'm sure a few will survive, but I expect the Corpus Christi's skyline will be palmy significantly differently going forward.

Thanks, Clay. TAMU is clearly a really special microclimate that doesn't reflect the rest of Corpus, so I am hopefully the trees might not be completely dead. An island + multi-story buildings surrounding the plants. I think I've shared pictures on here before - massive Ficus benghalensis, F. religiosia, huge Plumeria, Ceiba, etc. I am sure in the very least there will be significant dieback.

[Teegurr]

10 hours ago, NBTX11 said:

Should there be a small dot over downtown San Antonio making it a 9b, the Riverwalk in particular. 

Yes, there should. I just didn't have confirmation from someone - I didn't think about that too much, but yeah, that should be 9b.

[Jimbean]

@Xenon

You know your state pretty well, if you want, maybe you can help me out with this.  I'm using iNaturalist to look for post February 2021 cultivated royal palms.  I saw a total of five specimens in Port Isabel, South Padre Island, and Brownsville.  If you were to draw on a map the extent in which royal palms survived the 2021 freeze, where would that line be?

 

 

[Jimbean]

And the same with queen palms.  Many of these blue dots are either planted post 2021, or were photos taken before 2021.

[kinzyjr]

7 hours ago, Jimbean said:

And the same with queen palms.  Many of these blue dots are either planted post 2021, or were photos taken before 2021.

It may help to have a few verified before/after for the major metro areas to determine where to approximately draw the lines for the queens (9a?) and Royals (9b?) by your rating system.  Hopefully these links can help:

• https://www.palmtalk.org/forum/topic/71802-palmageddon-the-final-inventory/
• https://www.palmtalk.org/forum/topic/67385-palmageddon-aftermath-photo-thread/
• https://www.palmtalk.org/forum/topic/75854-palmageddon-royal-survivor-rio-grande-city-texas/

[Xenon]

18 hours ago, Jimbean said:

@Xenon

You know your state pretty well, if you want, maybe you can help me out with this.  I'm using iNaturalist to look for post February 2021 cultivated royal palms.  I saw a total of five specimens in Port Isabel, South Padre Island, and Brownsville.  If you were to draw on a map the extent in which royal palms survived the 2021 freeze, where would that line be?

 

 

Oh no, there are thousands of royals all over southern Hidalgo (McAllen, south and maybe <3-5 miles north of US-83 to as far west as Mission) and southern Cameron county (starting in Harlingen but more numerous south of there). 

Something roughly like this with the red line being absolute survival and the blue is where they become plentiful.

 

[Jimbean]

The red line on this map marks the royal zone limit and the yellow line marks the queen zone limit, within the context of the Feburary 2021 freezing event. 

[Jimbean]

If I have time, I'll look into drawing a Mexican washintonia line

[ahosey01]

@JimbeanAs a Brownsville resident I can think of at least 50 within a 5 minute drive of my house that are probably 20+ years old.

Also, Foxtails mostly survived the freeze in Brownsville.  Tons of those also.

[SeanK]

I'm not a resident, but I think that the 9a and 8b bands are a bit narrower. Texas can get a long stretch of warm winters then get slammed bad. To the west and NW are the high plains and Rockies.

[richtrav]

To be clear, there are no clean lines of survival, they are more like zones (50% survival, 80% survival, etc). On my street alone there were yards that lost their queen palms but a few houses down there are surviving royals that were out of the wind. And west of here where the lows were similar but it was a little drier, especially during the summer of ‘21, and generally fewer died from secondary complications but it varied. At one location in Sharyland an entire large yard of royals appear to have all survived, I suspect they may have been treated with copper fungicide or something, the survival rate was too high to be chalked up to random chance - especially when others in the area were hit or miss. 

 

[Jimbean]

11 hours ago, richtrav said:

To be clear, there are no clean lines of survival, they are more like zones (50% survival, 80% survival, etc). On my street alone there were yards that lost their queen palms but a few houses down there are surviving royals that were out of the wind. And west of here where the lows were similar but it was a little drier, especially during the summer of ‘21, and generally fewer died from secondary complications but it varied. At one location in Sharyland an entire large yard of royals appear to have all survived, I suspect they may have been treated with copper fungicide or something, the survival rate was too high to be chalked up to random chance - especially when others in the area were hit or miss. 

 

True, but I'm also being generous, any surviving specimen gets to be inside of each line. 

[Jimbean]

On 11/11/2024 at 10:43 AM, Jimbean said:

The red line on this map marks the royal zone limit and the yellow line marks the queen zone limit, within the context of the Feburary 2021 freezing event. 

So far, the red line is where royal palms survive, based on the last major freeze, and the same with queen palms where the yellow line I drew. 

[Jimbean]

Here's a list of all surviving royals recorded on Inaturalist:

Royal Palm (Roystonea regia) from Laguna Vista, TX 78578, USA on April 28, 2024 at 06:18 PM by debogey · iNaturalist

Royal Palm (Roystonea regia) from South Padre Island, TX 78597, USA on April 26, 2024 at 04:08 PM by johnyochum · iNaturalist

Royal Palm (Roystonea regia) from W University Blvd, Brownsville, TX, US on November 13, 2023 at 03:25 PM by Adrian Olvera · iNaturalist

Royal Palm (Roystonea regia) from Sugar Mill Rd, Brownsville, TX, US on February 12, 2023 at 04:48 PM by twofoxes · iNaturalist

Royal Palm (Roystonea regia) from South Padre Island, TX 78597, USA on May 02, 2022 at 11:42 AM by johnyochum · iNaturalist

Royal Palm (Roystonea regia) from W University Blvd, Brownsville, TX, US on November 13, 2021 at 10:49 AM by docbird · iNaturalist

Royal Palm (Roystonea regia) from Laguna Vista, TX 78578, USA on May 03, 2021 at 03:55 PM by debogey. A couple royal palms survived the freeze · iNaturalist

[Jimbean]

Surviving queen palms

 

Not in south Texas:

Queen palm (Syagrus romanzoffiana) from Galveston Island, Galveston, TX, US on September 30, 2023 at 07:00 PM by bhmosshart. saw on the street in galveston · iNaturalist

Queen palm (Syagrus romanzoffiana) from Tiger Courts, Laredo, TX, US on August 24, 2021 at 05:35 PM by Angelina Cerda · iNaturalist

South Texas:

Queen palm (Syagrus romanzoffiana) from Emerald Point on February 24, 2021 at 04:22 PM by Joseph Connors · iNaturalist

Queen palm (Syagrus romanzoffiana) from Penitas on October 03, 2022 at 07:08 PM by rcsanderstx · iNaturalist

Queen palm (Syagrus romanzoffiana) from Juan Diego Academy on May 02, 2022 at 07:58 PM by oleanderseth · iNaturalist

Queen palm (Syagrus romanzoffiana) from Harlingen, TX, USA on May 02, 2022 at 07:58 PM by johnyochum · iNaturalist

Queen palm (Syagrus romanzoffiana) from Marshall Ave, Harlingen, TX, US on January 14, 2022 at 08:55 AM by Cristopher Tercero · iNaturalist

Queen palm (Syagrus romanzoffiana) from Marshall Ave, Harlingen, TX, US on January 19, 2022 at 08:34 AM by gonzaleztori101gmailcom · iNaturalist

Queen palm (Syagrus romanzoffiana) from Marshall Ave, Harlingen, TX, US on January 18, 2022 at 12:30 PM by Huriel Alvarado · iNaturalist

Queen palm (Syagrus romanzoffiana) from Laguna Vista, TX 78578, USA on April 30, 2021 at 04:04 PM by debogey · iNaturalist

Queen palm (Syagrus romanzoffiana) from Laguna Vista, TX 78578, USA on April 30, 2021 at 03:42 PM by debogey. Queen palm recovering after the freeze · iNaturalist

Queen palm (Syagrus romanzoffiana) from Cameron, Texas, United States on May 01, 2021 at 07:40 AM by johnyochum · iNaturalist

Queen palm (Syagrus romanzoffiana) from W Fern Ave, McAllen, TX, US on April 30, 2023 at 08:13 PM by Jessenia Herzberg · iNaturalist

Queen palm (Syagrus romanzoffiana) from City Lake Park, Harlingen, TX 78550, USA on April 28, 2024 at 07:51 PM by johnyochum · iNaturalist

Queen palm (Syagrus romanzoffiana) from Laguna Vista, TX 78578, USA on April 28, 2024 at 06:15 PM by debogey · iNaturalist

Queen palm (Syagrus romanzoffiana) from Hidalgo County, TX, USA on April 05, 2024 at 03:38 PM by johnyochum · iNaturalist

Queen palm (Syagrus romanzoffiana) from Brownsville South Padre Island International Airport, Brownsville, TX, US on January 29, 2024 at 02:43 PM by calvinnering · iNaturalist

Queen palm (Syagrus romanzoffiana) from La Paloma, TX 78586, USA on September 27, 2023 at 09:19 AM by isidro732 · iNaturalist

Queen palm (Syagrus romanzoffiana) from Pharr, TX 78577, USA on October 05, 2023 at 06:10 PM by rjmendez · iNaturalist

Queen palm (Syagrus romanzoffiana) from Laguna Vista, TX 78578, USA on April 29, 2023 at 07:25 PM by debogey. Volunteer queen palm was noticed as a tiny plant in 2014 or 2015. · iNaturalist

 

Questionable: 

Queen palm (Syagrus romanzoffiana) from US-77 S, Kingsville, TX, US on March 30, 2021 at 07:47 PM by Eddie Cabrera · iNaturalist

Queen palm (Syagrus romanzoffiana) from Havre St, Corpus Christi, TX, US on November 14, 2024 at 08:28 PM by nathan_carson · iNaturalist

[Xenon]

Why are we using iNaturalist for cultivated palms? It's horrible for sampling/mapping palms. The observation timestamps can also not be trusted, users can always upload old photos for ID. Those queen palms in Galveston are definitely not there. 

If you casually click around on Google streetview in Laredo, there are plenty of surviving queen palms. Much much much more than in Corpus Christi, where they are practically non-existant (it's going to be a lot of clicking and squinting).

You won't have trouble spotting royals in Brownsville or south McAllen. There were practically no queen palm deaths in this area unless they were on death's door beforehand. 

There are some surviving queen palms out in the open in the Houston-Galveston Area but that woud probably be 1 survivor for every sample of 10,000 palms or some other insigificant percent. There are a few confirmed survivors far from the coast in Houston in Bellaire and Sugar Land. 

I'm not convinced there's much significance in drawing some lines statewide when there are so many variables at play i.e some areas are so poor that nobody thinks about plants period, some areas have outsized planting of palms for whatever reason, any slight nudge east/west on the trajectory of the arctic airmass would change things significantly, etc. 

[Jimbean]

2 hours ago, Xenon said:

 

I'm not convinced there's much significance in drawing some lines statewide when there are so many variables at play i.e some areas are so poor that nobody thinks about plants period, some areas have outsized planting of palms for whatever reason, any slight nudge east/west on the trajectory of the arctic airmass would change things significantly, etc. 

So we just have to do the best we can then.  If you wanna know what grows where in Texas long term, this is the best method in my opinion.

[kinzyjr]

Making a map like that is very much a best-guess, anyway.  That's whether the map uses @Jimbean/ @RedRabbit's method of using marker plants and significant weather events, or the map uses temperature data and statistical analysis.  It would be neat to see a map have overlays of both just to see how close they line up.

[RedRabbit]

47 minutes ago, kinzyjr said:

Making a map like that is very much a best-guess, anyway.  That's whether the map uses @Jimbean/ @RedRabbit's method of using marker plants and significant weather events, or the map uses temperature data and statistical analysis.  It would be neat to see a map have overlays of both just to see how close they line up.

That’s a good idea! I’m actually not sure what to base it on here given there aren’t many species of palms. You don’t really have Bismarckia or queens even. Washingtonia are here, but I’ve seen them way out in the hill country too so it’s not saying much that they’re in Houston. 

I haven’t been there in awhile, but I’m thinking Houston looks slightly more tropical than Valdosta, GA and less than Gainesville so that’s what we are working with.

[Xenon]

1 hour ago, Jimbean said:

So we just have to do the best we can then.  If you wanna know what grows where in Texas long term, this is the best method in my opinion.

I just think it's verging on misleading to make an assumption like that solely on the result of one particular freeze (2021). In the historical record, there are freezes that hit Laredo and McAllen harder than Corpus and Brownsville and vice versa. Houston is generally warmer than San Antonio, but occassionally there are freezes like 2018 that hit Houston harder (especially in terms of deviation from the mean).  Far southeast Texas towards the Louisiana border actually fared better relative to latitude in 2021. 

I just don't think it's stastically accurate or practical to say that Laredo is "more long term for queen palms" than Corpus Christi, it's just that in this singular freeze that's the way it played out.  

I'm curious what you guys in Florida are using as the benchmark for "long term"? Is it 2010 or the 1980s? Why should 2021 arbitrarily be used as the benchmark for "long term"? The absolute lows and duration of cold for 2021 deviated from the long term average much more than any other freeze in the past three decades, the next harshest freeze (2011) doesn't even come close to the degree of deviation from the moving (warming) mean. As far as plants go, I'm not convinced and won't tell others that 2021 is the defnitive freeze for what can grow where. 

I made some graphs a while ago, the data is absolute annual minimum at the Brownsville Airport. You can see post 1989 dots in bold and there's a table that represents the "weight" of the freezes relative to the regression line (the mean absolute annual minimum over time). Hopefully it makes sense, not wanting to get too bogged down with numbers and graphs (also been a while since I've done statistics lol).

More and more I'm just not a fan of any of these types of maps period 😛. Especially when you try to cover a huge area like Texas 

[kinzyjr]

11 hours ago, RedRabbit said:

That’s a good idea! I’m actually not sure what to base it on here given there aren’t many species of palms. You don’t really have Bismarckia or queens even. Washingtonia are here, but I’ve seen them way out in the hill country too so it’s not saying much that they’re in Houston. 

I haven’t been there in awhile, but I’m thinking Houston looks slightly more tropical than Valdosta, GA and less than Gainesville so that’s what we are working with.

Basically, you're somewhere around a Lake City, FL planting scheme?  Either way, good to see you're adapting to your new environment well.