Dallas, TX - Palm survival from February 2021 historic freeze - 10 days below 33F/1C (Only 1 hour at 33)

[vcrosstx 4]

I've lurked on here for a long time but never signed up and never posted. I wanted to go ahead and sign up now to share my observations after the once in a century freeze we had here in Dallas, TX USA in February 2021 and the effects on palms, cycads, and other subtropicals. Temperatures were below freezing in Dallas for around 232 hours in duration with just a couple hours above freezing (33F/1C). Snow fell a couple times and we had powder on the ground for 7 or 8 days up to 6 inches / 15 cm or so). Even on sunny days the snow was powder. I had only seen that in Colorado. One day our high temperature was 1 degree F below our record low temperature! (High was 14F and record low was 15F). Dallas proper dropped to 2F and the airport dropped to -2F (-19 & -17C respectively). This caused a near collapse of our power grid and deaths of over 200 because of power outages.

I have lived in Dallas since 1995 and grew up in Louisiana. I had seen the aftermath of freezes in 1983, 1989, 1995/96, 2011, etc. I was expecting damage to be equal or worse to 1983 and 1989 freezes so expected most of my yard to be wiped out along with most palms in the Dallas area. Dallas had a good run after 1989, so there were a lot of mature Washingtonia filiferas and hybrid W. filifer x W. robusta along with Sabals, Trachies, Butias, etc.

What I have observed as of January 2022

Palms:

• Sabal minor, Rhapidophylum hystrix (Needle Palm) - Zero damage at all. Completely unfazed - from an evolution perspective, these have seen this many times over the centuries
• Saw palmetto, Serenoa repens 'Silver form' - froze to the ground and sent out a spear by May 2021 - another native to the Southeast USA so had to have been adapted over the centuries as well and survived the Ice Ages
• Trachycarpus fortunei - maybe 5% death rate for mature specimens and 10% or more for medium size
  • All were defoliated but those that were not overtrimmed definitely bounced back faster. In my yard, one that I had skinned and trimmed high died
  • I am seeing at end of the year more and more mature specimens have died, but in almost all cases they were all over trimmed on a consistent basis
• Sabal mexicana
  • Surprising cold hardy winner. Most established specimens survived and leafed out by end of summer
  • Survival rate in Dallas is better than Trachycarpus for mature specimens (I would have never believed)
• Sabal palmetto
  • Less common in Dallas, but seems established specimens survived at least 80% or more
• Butia - They do not love Dallas
  • I've only seen a couple that have survived - I've killed several in my yard and one with 6ft / 2m of trunk died
  • In my hometown in Bossier City, Louisiana, they all seem to have survived
• Washingtonia filifera
  • Shocking but maybe <5% survived - tall and mature or at the 3 to 5 ft height level (1 to 1.5 m)
  • None of mine did
• Washingtonia robusta and hybrids - 0% survival
• Phoenix canariensis  - Canary Island Date Palm - shock
  • I've documented 3 that survived and there must be more. No protection

Cycads:

• Sago revoluta - most froze to the ground but resprouted with many pups. Surprisingly many with trunks in the center city sprouted back out from trunks that were 2-3  ft  or more / 750-100 cm.
• Dioon edule - resprouted for me - 2 specimens; looked just fine by summer

Popular Shrubs:

• All Indian Hawthorn died to the ground and only maybe 5% have since re-sprouted from the roots
• All Loropetalum died to the ground but most regrew very anemically with mostly yellow/discolored leaves
• All pittosporum died (variegated upright forms and lower sprawling forms)
• Most Ligustrum severely damaged or died including the invasive species that are tree-form
• Fatsia killed to the ground but resprouted

Trees:

• Tree form Ligustrum dead
• Arizona Ash - killed to trunk or dead
• Live Oak - Most defoliated and came back fine; maybe 5% or more killed back to major limbs but resprouted, minor limbs dead; many actually died but maybe just 1 or 2% - surprising since native very near here
• Random other trees - I just see random trees in neighborhoods that wear still bare in September/October - assume they are dead

Agaves/Succulents:

• 90% of agaves were mush but there were a lot there were just fine. I don't know species but Agave ovatafolia seemed fine as well as Agave scabra
• Golden barrel cactus - none I know of survived
• Opuntia - Many specimens with pads reach over 2m collapsed while others were just fine

 

IMG_0251.HEIC IMG_0252.HEIC IMG_0249.HEIC IMG_0246.HEIC IMG_0243.HEIC Sago 2021

Edited January 13 by vcrosstx
added cycads report / removed duplicate image posts

[necturus 560]

Nice observations. The data about CIDPs and W. filifera is especially interesting. It's obvious CIDPs are remarkably cold hardy, but most would consider W. filifera more hardy. This may be a climate thing - perhaps W. filifera is tougher in a dry climate, whereas CIDP is tougher in wet climates.

With respect to Arizona Ash - good riddance to bad rubbish.