Cocos Zone 10a

[ahosey01]

It looks like my wife and I will have to move (unexpectedly).  Bummer for how much work I've put into the garden, but such is life.

Anyways - plan is tentatively to relocate to a solid zone 10a in western Arizona - Bullhead/Havasu/Yuma area.

Any chance I can grow Cocos here?  Should be hot as hell and rarely freeze.  There are weather stations in this region with half a century of data that have never recorded temps below 28.

Curious!

[awkonradi]

There are Cocos in La Quinta and Mexicali.  Would Yuma be worse?

[ahosey01]

5 minutes ago, awkonradi said:

There are Cocos in La Quinta and Mexicali.  Would Yuma be worse?

Between all of them, Yuma would be warmer than La Quinta and probably identical to Mexicali. Bullhead City and Lake Havasu would be warmer than all of them.  The all time low in Bullhead that I can find from any station on DRI was 25, just slightly colder than Miami FL’s all time low.  I have found a couple (near Laughlin airport for example) that are 10b most years and have only ever got to 28.

Edited July 27, 2021 by ahosey01

[awkonradi]

Well, if you grow one in Bullhead City, that would be at latitude = 35.1 - 35.2 North, and therefore maybe the northernmost coconut in the world.

Edited July 27, 2021 by awkonradi

[chinandega81]

Don't look at all time low as the only factor. The Mexicali coconut is no longer there, the site was redeveloped. Mexicali is a major urban heat island...none of the other cities have that going for them. Wall to wall concrete kept temps just warm enough to keep it alive during prolonged cold spells. The La Quinta coconut is in a unique cove off the valley floor, away from cool draiange.

I don't see why, in a location shaded from west sun and NW/N winds, you couldn't try a coconut in Yuma. The thing that ultimately kills them is a slow decline from overall unfavorable weather. The winters have many days with high temps in the 60s and lows in the 30s/40s. It isn't like FL where the norm is in the upper 70s and there are a handful of 60 degree days. It is the opposite in Dec-Jan-Feb in the southwest. You will get several up to 2 week stretches with highs in the 60s and lows in the 30s.  It is just too cool overall in the winter,  even with the contrasting 2 week warm streaks in the 70s and 80s (lows still in the 40s). The dryness and wind doesn't help either.  Add in the stress of the summer heat (over 115 many times), with a lack of natural rain. and coconuts naturally decline and do not thrive unless in a majorly favorable microclimate in the southwest.

It can be done, but I wouldn't pick one of those cities to live in based on them being more favorable for coconut palm growing. They are all marginal with different pros and cons in that regard. 

A good indicator is to look for mature Royal Poincianas. Mexicali has many but most would be "stunted" by Florida standards. PHX has a few large ones, but many have die back. Yuma also has a few moderate sized ones. Wherever you choose, if the RP sufferes from die back, a coconut won't make it.

[mnorell]

Just in relation to the statement about La Quinta Cove, I can say that it is not really a unique, nor a particularly favored, microclimate in the Coachella Valley, more likely falling into a "slightly favored" category. All of the coves that rest on alluvial fans along the western side of the Coachella Valley are by definition cold-air-drainage throughways. The Santa Rosa Mountains, and particularly the much higher San Jacinto ranges, are cold-air factories at their highest elevations, and that snow-chilled air runs down through the various canyons down into the valley, particularly into the Whitewater River drainage basin, where air is the coldest on winter mornings (and hottest on summer afternoons!). My area (Magnolia Falls Cove, in Rancho Mirage) has a very similar temperature profile to the La Quinta Cove, lying also on an alluvial fan with cold air running down over our property from the Magnesia Falls canyon areas. At sunset the cold air is palpable as it runs down through these areas, and a walk in our neighborhood at sunset, for example, includes wildly variable temperature swings when walking through canyon-exposed vs. drainage-protected areas.

The winter-warmest areas in the Coachella Valley lie just below the typical winter inversion, in the 600-900 ft. elevation areas, good examples being the highest elevations in Palm Desert and Cahuilla Hills along the 74 as it ascends into the mountains, and at the highest elevations of the Cathedral Cove. In those and similar spots, winter mornings are astoundingly warm, often 10-15 degrees warmer than most other areas, including those of us who are at the "slightly warmer" 300-ish ft. elevation level. What I have learned through my own experiments (and a cue from the the way the La Quinta coconut grew under the shade of other plants) is that they will generally fail if planted under open sky while young. They will do quite well under the shady and somewhat warmer canopy of trees (preferably south-facing in a winter-sun-trap area), where they can grow up and into the open atmosphere over the years.