Hello kinzyjr,

I read a lot of data about our low and it was confusing. According to some german website´s like "wetter.com", our low was about 5F in the Aiport, this means the coldest place here. I saw here a lot of P.Dactylifera near house wall´s and minimum age of 5 year´s, this means they survive even temperature of 1F according to NOAA. Even adult P.d. wouldn´t survive this temperature, perhaps in Las Cruces with -9,4F (http://www.lascruces-weather.com/wxrecordsalltime.php) . I think our climate has more similarity to Las Cruces as regards Elevation, Precipitation, Record low, Average low and Average high from 2000-2015.

Regards

Source : http://climatebase.ru/station/40745/from2000/?lang=en

"Just by seeing a date palm, I would have guessed 8b or above." I didn't see a mature one.

Without spending too much time on this (ahem, I did after all!) ,probably this is at least a zn 7b-ish climate but the first climate link you posted is wildly erroneous. The notion that a 3000 ft elevation in Iran, even northern Iran, would reach -41C is insanity. The figure given in the wikipedia article is still surprisingly low, but plausible: -28C/-18F. (for perspective, this is the all-time low Dulles airport in Northern Virginia! At about 41N versus 36N, but only 300 ft. of elevation.)

A handful of mature dates supposedly survived a -10F radiative freeze in extreme SE NM in the 1960s. I can actually believe that: but in must be pointed out that is a different kind of desert climate than this city of Iran, with drier, warmer, and yes, sunnier winters. 150 hr. of Jan. sunlight in Mashhad, vs. 250 hrs. in El Paso. And average low of 22F versus 32F. Why? So...my understanding anyhow...is winter low pressure systems often make it all the way from the Med. (which gets much warmer in summer than our CA/Baja coastal waters) all the way along Asia Minor, northern Iraq, into Western Asia, and finally to the Kashmir and extreme western Himalayas. The Black and Caspian seas probably give little boosts of moisture along the way. (and, right near the coasts in Iran and Turkey, narrow microclimates with very high rainfall) Thus they have an early winter peak of moisture, while our interior SW has a summer peak. These low pressure systems presumably account for the lower winter sunlight there. The outer limits of the Siberian High during the rest of the winter accounts for the lower night temperatures.

Anyhow, I think date palms might survive a few years in that area, but not for very long if some winters hit -18C/0F, especially since those freezes would probably have a somewhat advective characteristic.

Hello David,

At first, thank you for your comment.

This data on wikipedia are not up-to-date (1961-1990) and about the coldest place here. Betwen Mashhad/Airport and Mashhad/Downtown is 5°C difference. Maybe our Airport is 7b and city sould be 8. But I am sure, it will be 8a or b, because Nerium Oleander grow here very well and this plant is a 8a plant. I saw 7ft Oleander and this plants are max. hardy to -12°C. Even Olive tree´s survive easy our winter according to local farmers.

BTW, i dont compare Mashhad with El Paso. I compared Mashhad with Las Cruces and there is no big difference (exception mean monatly sunshine hour) according to the updated data of Mashhad.

http://www.weatheronline.co.uk/weather/maps/city?LANG=en&PLZ=&PLZN=&WMO=40745&CONT=asie&R=0&LEVEL=162&REGION=0024&LAND=IR&MOD=tab&ART=TMN&NOREGION=1&FMM=1&FYY=2000&LMM=12&LYY=2015

ehsan, well good luck with whatever you try. It's nice to connect with a horticultural pioneer in another part of the world.

However, if the older climate data is even close to correct...there's going to be a real difference getting a Phoenix to recover from a freeze in your area vs. SE NM/West TX. Sure LC could be a little cooler than EP, and maybe your city center is a little warmer than what I saw at the wiki article. But look at days of precip in winter. You have almost twice as many as those places. Still not many compared to say, London, but that's a significant difference right there and probably indicative of freezes having a more advective character. I was in Las Cruces literally 48 hours after a huge freeze they had in 2011. (completely by accident! I didn't travel there to see freeze damage!) It was already in the 60s during the day, sunny, warm and crisp. That's one reason a lot of palms that were damaged there could recover. If your city is drizzly and chilly 48 hours after a freeze, that could make the difference. Or not. If I were there, I would want to try date palms too. Are there many mature ones in town?

Hello David,

You are right!

I saw within a year serveral times changes in the wikipedia article about Mashhads climate. Wikipedia should be treated with caution and I use more local websites or orther websites.

According to iranian websites our climate is a Csa ( right???) and it changes from cold temperate to warm temperate climate. Our low was -3,5°C (Airport) in winter 2014-2015 but 2013-2014 -15°C but -15 is a exception like -10°C in Dallas (2013-14 &2014-2015). Even after alleged -15 (?) Agave americana, Cycas, Phoenix and oleander survived with no damage. I dont saw any big Phoenix but i heared from several tree nurseries, that there are some big Phoenix and Washingtonia. But i saw in Tehran very a lot of Phoenix and Washingtonia and not near protecting walls.

Regards

Ehsan

David?? :)

quote, ' Any young plants, especially oleanders, olive trees, fig trees and citrus trees, are probably lost.', unquote

source :

http://newscenter.nmsu.edu/Articles/view/7556

That is´nt what we expect from LC. Even young fig trees died :(