Looking great Virginian! Long time no see, where you been hiding? We need more representation from your neck of the woods.

Just a simple question, exactly when was that -10 degree low measured? Exactly where was it measured, and by whom? Just the facts, please.

Bradleyo: I have been spending lots of time on our Virginia Palm Society on Facebook which is growing and growing with members from all over Virginia, many states and countries from around the World. We have also been occupied with getting papers published at Virginia Tech, speaking to scores of garden clubs and getting palms planted in public places like the cascades library and firehouses. If you are on Facebook send us a request and we will let you join the group to participate. You would be most welcome.

So no facts, or just don't care about them?

This is a really interesting topic. It would be great to see more posts of established specimens in the area.

As for the -10F reading, I am highly skeptical of that anywhere in the greater DC area in the last 20 years. Maybe well well west/north of town in rural, higher elevation areas. Downtown DC barely sees below +20F during winter in recent years.

Awesome trachy! It has definitely seen some pretty bad cold if it's been around for almost 20 years and it looks beautiful. It can easily be mistaken for a trachy in a much milder climate. The size of it is incredible also. I can only hope that mine will be that size some day!
Thanks for sharing

Tropicalzone7: Thanks and it is amazing to see in person when you realize that it has seen several documented NWS subzero temperatures and remains looking so healthy and untouched. 20 years in the ground unprotected and facing not only documented USDA Zone 7a temperatures and some out of zone subzero nightly lows not to mention some serious snowfall. This palm is in the outer suburbs in Loudoun County, Virginia so it gets no heat island effect as one might get below the fall line and in the city of Washington. We checked all the NWS data and even took temperature readings on a 4F night where the temperature of the palm, the ground and 3' from the house were all the same temperature. The house itself was only a couple of degrees warmer, so it has faced nightly lows that have been very cold for our area. There was nothing for this palm to "huddle up with for additional warmth" LOL! Some naysayers from much colder parts of the country might say we have had "a string of mild winters", but the data from the NWS says otherwise and we have had consistantly in USDA Zone 7a winters for years, maybe a bit colder on average. Trachys once they are established are much more hardy than one might think and this super survivor by its very existance in thriving proves out most difinitively. Again, thanks for the kudos and we will have pictures to post next year when we have the ceremony.....20 years of no palm protection other than some normal mulching....this according to the original planter of the palm. The current owner doesn't always do this either.

Guess it's up to me to provide the facts (which for some reason gets me labeled as a "naysayer"): the claim of surviving -10 degrees is based on the historic record of a single night's reading several MILES away at Dulles Airport, at the center of a known cold pocket; on that same night the low at DCA was 5 degrees. (BTW this happened years before "The Virginian" ever laid eyes on this palm.)

It seems the person to provide the most accurate information about the palm during this time period would be its owner. As it happens, the person who planted it and grew it during those years (before selling the property to its current owner in the early 2000's) is a personal friend of mine and we have had many conversations about this palm. He does not believe it ever experienced any temperatures below zero, at least not while he was growing it (1994 to approx. 2003).

The palm my friend planted is absolutely impressive, is almost certainly the tallest and oldest windmill palm in the entire Washington, DC area, and has experienced some very cold temperatures--MAYBE down to zero, but not for any extended period, and anything much lower is unlikely. BTW one thing the above photo doesn't show is that the palm is planted right up against a masonry foundation, with a fence on the other side, and was very small at the time. My friend firmly believes his palm's success is due to good siting in a sheltered location and good care during the establishment years--the two most important factors in growing hardy palms where they are marginal. He does NOT believe it has any particularly unusual hardiness.

BTW check out the below blog post (while noting that it does NOT include our recent 3--and unusually warm-winters):

Here is a link that might be useful: High and low temperature by year at Washington, D.C.

OK, since you want a war of facts or in your case conjecture, the temperatures taken at the Sterling NWS station are less than 4 miles away from where the palm is planted that night when temps actually dipped to -11F as recorded, and yeah, sure somehow there was some "miracle" microclimate that surrounded the palm. It is absurd to even seriously think that somehow at night, the temperature would be more than 10F+ warmer. You like using temps recored 20 miles away at DCA and what is amazing, it is not even relevant since that area is below the falls and near DC in the tidewater. The Sterling Trachycarpus is planted 22 miles away, above the fall line not far from Dulles Airport as the crow flies and even closer to the Sterling weather station. Neither you or friend by your own admission, took temperature readings and the weather station did, so how can you even begin to make a credible statement that "you don't think" it experienced those temperatures when a few short miles away it was -11F? PLEASE give me a break you have NO DOCUMENTATION WHATSOEVER to back your claim up. We do from the NWS and again, it is absurb to believe anything else but the documented temperatures. You go out on an -11F night and walk up to a house a few miles away facing south and take a temperature reading and as sure as the sun sets in the west it will be -11F or a degree or two close to that, not 10F warmer. As I stated before I went out on a 4F night and actually took several readings by the palm and as I stated in the previous post, the palm, the ground the dirt right next to the house and serveral feet away from the house were all 4F. Only directly on the wall on the house on the foundation were 2F warmer, the palm doen't even touch it. Until you have direct experience taking temperature readings or work for the NWS, don't promote your conjecture as fact here on the boards. I want to make sure people get the right information and not speculation based on your feelings of what you want to be true. You and your "apostles" can believe the moon is made of green cheese too, but the facts have proven otherwise. You are all wet Soggy Boggy, you just have too much angst to face the reality that the Sterling Trachy is a long term survivor that has faced subzero temps and it doing just fine in USDA Zone 7a. No mild winters and no miracle microclimates and 100% rock hardy. Just the facts....

Now that this has devolved to juvenile name-calling (sadly, I expected no better) I guess I'll just let others decide which of us has the better case. But one last link in parting: differences of up to 12 degrees over short distances were documented by Francko & Wilhoite (2002), who wrote,

"Sheltered areas near large buildings on the Miami University campus... are consistently 5.0�"6.7úC (9�"12úF) warmer than rural areas and effectively Zone 7a to 7a/b microhabitats."

Here is a link that might be useful: Cold-Hardy Palms in Southwestern Ohio: Winter Damage, Mortality and Recovery

Boggy: Read this, it confirms your assumptions on DCA data being relevant for the suburbs is pure is balderdash....
Plus, that is not a microclimate, it gets no sun at night and is not surrounded by concrete.Unlike you I have personally taken temperature readings there. Funny you would rely on Dr. Franko's data since you like to trash it on other boards with relish.

Here is a link that might be useful: DCA Temperatures

Who really cares might be a better question...

I have a Trachy (Fortunei") that survived -2F with a trash can over it-
it did spear-pull.
There are other cases(many) of Trachys surviving below zero(F) temps
like the Bulgarian Trachys,so this is really not news,Trachys have survived
below zero before.

Jim,

I agree 100%, too many people with their head in the sand. Pretty cool stuff.

Boca Joe

That's a cool palm!

It was -10 at Dulles Airport (Sterling, VA) on February 5, 1996.

Here is a link that might be useful: DAILY NORMALS AND RECORDS FOR THE MONTH OF FEBRUARY FOR DULLES AIRPORT

Yes, that's the record that is the basis for this claim but the weather station where it was recorded is about 4 mile away from the location of the palm. What it boils down to is whether you believe it was the same temperature at both places. I'm simply saying that's not a safe assumption, and it's not sufficient to make an unqualified claim.

It's not particularly outrageous to point out that temperatures can differ by several degrees over several miles (seriously, does anybody doubt this? Anybody?) or to suggest that an extraordinary claim (based at best on circumstantial evidence) should be taken with a grain of salt. Take the facts and do what you will with them, but it should tell you something that I'm being attacked, rather than the simple facts I'm presenting.

Again, it was -10F at Dulles, -11F at Sterling-not the Airport station and with your line of reasoning in theory, it has at least an equal chance of being EVEN colder in that yard at night as it would being a degree or two warmer. It is highly unlikely that it was indeed many degrees warmer as alluded to in this thread. In any event, this is the suburbs and nearby Reston, VA was the same temperature as Dulles, and is about 4 miles away too. I guess these "hate facts" are being perceived as some kind of attack, rather they are only clarifying. Even still, the palm is there, saw this and other subzero temps and as Jim points out, it is no big deal or "headline news" when it comes to Trachys. Thank you Restoner for posting the supporting information.

It seems we have reached a watershed event. No longer is the argument whether or not a palm can survive Winter in the DC area. Now it is if it has ever survived a subzero jolt within the Winter.

Blarney or not, that is progress.

):

It seems we have reached a watershed event. No longer is the argument whether or not a palm can survive Winter in the DC area. Now it is if it has ever survived a subzero jolt within the Winter.

Blarney or not, that is progress.

):

Regardless of the actual temperature the plant experienced, 2 decades in a non-coastal area in VA is something to celebrate. As jacklord said, progress!

Thank you folks and we are as amazed as anyone that this large trunking palm has done so well for so many years. We will be sure to post pictures and links to videos of the celebration ceremonies next spring.