December 2022 temperatures in US palm growing regions

[bubba]

LA 81F/44F- 56.52F  Palm Springs 83F/39F-57.73F/ Phoenix 73F/38F-54.68F  Brownsville 83F/27F-63.39.F  Houston 84F/17F-58.74.F  NO  81F/25F-58.03.F  Jacksonville 82F/20 F- 55.65F Orlando 83 F/30 F-63.35F Miami  85 F/46F-71.99F

During this season of arctic incursions, the south western US has been relatively cooler than usual. That stated, there have been no extreme low temperatures but a rather constant march of low temperatures in the lower 40sF. The median temperatures of 56.52F, 57.01F and 54.68F provide the reasons for the inability to grow the truly tropical species, except for those renowned microclimates.

Texas has been inflicted once again by the unfortunate arctic incursion, but relatively briefly. Brownsville recorded a low of 27°F but maintained a nearly tropical median temperature of 63.39 F. Houston suffered more diabolically with a low temperature of 17 F, but with a median temperature of 58.74F.

New Orleans suffered a low temperature of 25°F during the artic incursion around Christmas but had a median temperature of 58.03F. The lower  Bayou area continues to support citrus as well as an occasional royal palm.

Florida was affected by the arctic incursion, but the location in the state defined the effect on tropical specimens. Jacksonville recorded a low of 20F with a median temperature of 55.65F. This was certainly colder than usual but the beach areas were much more hospitable with lows between 25F-27F. Orlando showed it’s susceptibility to the arctic incursion with a minimum temperature of 30F but the median temperature of 63.35F shows the clear bounce back afforded by lower latitude and why zone pushing tropical specimens works well. Once again, the median temperature borders on tropical. South Florida/ Miami recorded temperatures in the lower 40sF but the median temperature of 71.99F demonstrates why Cocos nucifera and other tropical foliage predominate.

January and February remain. Additional artic incursions will define the cool season in the continental US in 2022-2023 and the effect on tropical specimens. Sunset zones rather than the USDA zonal system are much better predictors of what grows.

 

 

[kinzyjr]

2 hours ago, bubba said:

Sunset zones rather than the USDA zonal system are much better predictors of what grows.

The USDA system isn't perfect, but does anyone honestly believe that Brooksville, Inverness, and Ocala should be in the same zone as the inland area southeast of Lake Okeechobee and south into the Everglades? 

Sunset Zone 26 spans this entire area.

[RedRabbit]

4 hours ago, kinzyjr said:

The USDA system isn't perfect, but does anyone honestly believe that Brooksville, Inverness, and Ocala should be in the same zone as the inland area southeast of Lake Okeechobee and south into the Everglades? 

Sunset Zone 26 spans this entire area.

It’s as though they didn’t even try with that one. 🙃

[bubba]

Kinzy and RR make good points about Sunset’s treatment of Florida’s climate. Sunset does best in the western continental United States and for years did not include the eastern continental United States, including Florida and south Texas (RGV). It does now but is flawed.

The issue that I find debilitating with the USDA zonal system is that it does not take into account the amount of heat in a climate. Specifically, a true USDA zone 11 could be found in a climate that experiences highs and lows between 45F/40F year round but never drops below freezing. You certainly will not be growing coconut palms in that climate, notwithstanding the fact that it has never experienced a freezing temperature.

Only the Koppen climate classification, which designates a climate tropical in the event it’s median temperature in the coldest month of the year is 64.8° F or higher, considers the effect of total warmth in it’s designation. Unfortunately, it is highly flawed as well. Although likely impractical or logistically impossible, the ultimate truth, as it relates to climate designation, should be which palm or plant flourishes.

[ShadyDan]

The PNW was much colder in December than usual too, like most of the continent. Victoria International (sorry not US I guess but close enough) had a high of 12.4C, low of -8.4C, and an average of 2.5C. The yearly average in Victoria in December is 4.0C and that -8.4 low is a once in 20-30 years event (although last year was damn cold in December too!).

I don't even bother with the Sunset system as I find it flawed in its own right. It classifies most of Eastern Vancouver Island as Zone 4 (the same as Southern Alaska... ya right!).  We should realistically be in Zone 5, the same zone as Seattle. Although, even in zone 5, they have the west coast of Vancouver Island in that zone too. That part of the Island receives ~4x the rain we get and has much less summer heat/sunshine. Even the native species that grow on the dry East side of the Island (Arbutus, Douglas fir, Garry oak) are nowhere to be found on the West side. Good luck getting any heat loving fruits and vegetables that do fine in my area to ripen on the West side without a greenhouse (tomatoes, peppers, persimmons etc...). I don't know what zone we should be but we certainly shouldn't be lumped in the Alaska or Western Vancouver Island for an accurate portrayal of climate. 

I'd rather use the USDA zones with the basic knowledge that my 8b will be different than a Southern 8b when it comes to heat units. I also do like that Koppen classifies our part of the world as Csb as well. The Mediterranean climate designation is pretty accurate as our summers are quite dry and many ornamentals rated for our zone with wetter summers will struggle / die without supplemental summer water. We can even grow Mediterranean plants like grapes and olives with minimal fuss, and things like bay laurel, figs, and rosemary thrive here.

My 2 cents about climate classification.