Check out this site:
www.palmpedia.net/wiki/SUBTROPICAL_SURVIVABILITY_INDEX

They're grouping palms on the basis of having similar climate requirements. The listing makes it easier to pick which palms will grow in any area. If you know that one species will grow there, the list will give you all the other palms that will grow there as well.

Unprotected and un-coddled, not many. As you already know, it will depend on what kind of protection and water you can provide. Depending on the lengths you are willing to go, it could be an extensive list. Otherwise, quite a short list. High desert can be challenging, but I have visited fantastic gardens in Palm Desert with extensive collections of Coccothrinax, Hyphaenae, Livistona, Copernicia even, and all in the ground. What is your elevation and conditions?

very good info. thank you! its just weird how palms are cuz there rating washingtonia robusta 22*f but here in my area i no personally they saw 13*F breifly. but then again in winter were always below freezing 75% of of all nights durning winter. were a harsh zone 8b but it puts are palms to the test but they have a decent spring(except this years been like are old years,always in the 90's) great summer & fall! but winter is extreme here, thats why palms are so hard to classify! also in 2007 the palms that survived were canary & date palm, california palm, mediterranean palm, blue mexican, windmill, pindos, sagos, & a few queens! but im planning on add more to that list!
thank you!
james

elevation about 3800 ft. kind of harsh conditions but minimum temp. 20.3 which puts us a zone 9a by only a 0.4 degrees! so i still call my area a decent to strong zone 8b. past 4 winters we hit low 20's despite 2007 which was 13*f!

palm desert is a solid zone warmer then us! theres no way i can even get a bismarckia to survive!

Well I would start off with the more cold hardy palms first and a plant a few other trees like pines or live oaks. The over head canopy when they get bigger will provide a micro-climate a little bit warmer than out in open. That may make all the difference to any less cold hardy palms planted under them. Also any of your walls that are facing south are also warmer micro-climates.
Good luck :)

- US_Marine

Generally palms are more cold tolerant in the southwest than they are in the rest of the US. Probably has to do with the extra solar radiation, or maybe the drier winters. Either way, it seems like palms can really reach past their limit there which means toucan grow a lot. Here's a list from most cold hardy to least that should do well for you. Some will need extra water in your climate.

Needle palm
Sabal minor
Blue Mediterranean fan palm
Trachycarpus
Mediterranean fan palm
Braheas
Mazari palm
Pindo palm
Date palm
Livistonas

You can definitely grow at least 30 different species and even more with protection.

Thank you all for the suggestions, looks like a canopy is going to help me achieve my maximum number of palms in my yard. I've started one with California fans,canarys,brahea edulis ,pindos & a few more I need to put in still but those are in now. But I have a long ways till it all fills out!
Thanks again, James

The mule palm is a great palm for the high desert area... I planted two last spring along with canaries and date palms. The phoenix palms are frost burned but the mule palms show no damage to speak of. I know the phoenix palms will bounce back come spring. Its just sad to see them looking so shabby. Do canary palms get more cold hardy over time as they mature?
I am also experimenting a couple of bolivian coconut palms and a phoenix reclinata. Still to early to know if they will survive our winter.

I just (sadly) moved to your zone and dragged some of my transplants up from Los Angeles. So far, the wind has been the primary factor in limiting growth (as well as trasplant shock). Butias and Trachycarpus fortunei transplanted well. Most others did not. I have a Chamaedorea radicalis that is doing well. Still too early to say how othes will do, though Jubaea looks like a good choice, too.

As far as cycads go, most Encephalartos are quite unhappy about the cold winds and look bad... but if protected from the winds, or planted under a pepper tree, most seem OK. The smaller Macrozamias are unhappy, but more from summer and constant winds than winter. Larger Macrozamias tolerate wind a bit better and none seem upset by cold yet (only gotten down to 22F so far). Most Dioons have no cold worries, but some have been pretty desicated by the hot summer winds. Zamia integrifolia is OK, but mine is growing in shade. Too cold for most of the other Zamias. Cycas panzihuensis is OK with weather so far, but again, winds make the fronds look bad. Cycas revoluta gets wind bent and a bit yellowy if too exposed, but otherwise no problems. Most of the other cycas I brought up were immediately defoliated by both summer and winter. Not tried a Ceratozamia. It seems protection from winds is the most important when it comes to the cycads.

I like the silver Med palms. And the silver weeping 'Clara' Brahea. You can get a fast palm oasis look using them under our native fan palms.
And then there's the Argentinean Trinax campestrus. Plant a few giant Trichocereus cacti from the South American high deserts..hardy to single digits at least when of size.
The key is don't waste time and money on slow and tender palms,and their deaths or slow recoverys. Use those as potted accent plants..if even worth that.

Here's my results so far:
Past 2 years been challenging but the palms that pulled through, Washingtonia filifera/ robusta ( with robusta getting defiolated last winter & this winter) Chamaerhops both green & blue perfect despite cerifera slight damage first winter. Pindos slight damage first year, nothing so far just on 1 recent transplant last year. Phoenix canary's 1st year defiolated this year doing good. Brahea edulis slight damage both years but better this year(strong palm for zone 8b) Sabal pumos slight damage. Trithrinax campestris 2 palm plant 1 had spear pull ( fully recovered & doing fine this winter) nannorrhops arabica ( Iranian silver) slight damage both winters ( seems very promising) planted out at a 1 gal. Trachycarpus fortunei slight damage 1st year none this winter. Sabal blackburniana, this 1 didn't get a fare chance I move it before last winter hit & never recovered but still alive I can't access this 1 properly. Phoenix theophrastii defiolated & spear pull 1st year ( fully recovered) this winter has some damage, canariensis seem a bit hardier but to early to till, planted theophrastii out at a 5 gal.

Ok the ones that didn't make it: Queen Palm defiolated 1st year & didn't recover by next winter, didn't make it. Trithrinax brasiliensis planted out at a 15 gal. Died 1st winter( pretty surprised with this 1, but might try again) Acoelorrhaphe wrightii died 1st winter. livistona nitida died 1st winter. Livistona's might not make it up here don't seem to take much cold but I still want to try a few more & try nitida again.

1st winter we had a hand full of low & mid 20's with are lowest being 19*f two nights in a row followed by 22*f the 3rd night with the low going up the next few days! No protection on any palm except a potting bucket over Nannorrhops, livistona nitida, acoelorrhaphe wrightii.

This winter almost the same as 1st with are lowest temp so far 20*f. But it's ben nice the past few weeks & I hope it stays this way or lease temps don't get below 22*f I shouldn't get any more damage! Winter protection I put sheets on most palms except Washingtonia's, Chamaerhops, Trachycarpus, butia's. & a bucket over nannorrhops when it rained with sheet.

Oh yea I forgot about Phoenix reclinata, 1st winter fried with the biggest trunk die& this winter fried but still alive! Strong little palm but protection is gonna be key for this 1. I have mine planted with a eculyptus tree but it's still a small tree & doesn't offer any protection yet.

Whiteside, I still wanna get my hands on a mule palm! Maybe this spring. Let me no how parajubaea does for you, which 1 you trying?