It's definately not the cold that's hurting them. I planted a seedling outside last year, it went through our winter and it is still going strong today. It went through low 30s quite a handfull of times so i'm sure your nights are not what't doing them in. Could it be that they dried out at some point? Did you recently transplant them?

I don't want to tell you this but they look dead. They will never do good in your climate because they need lots of humidity and can not take temps below 26 degrees ever not even a short time.Also they can not take full sun with temps over 100 + because they will fry.I personally would try another palm if I was you. Sorry if I sound negative I just want you to know the truth.

They are recent transplants about a week and a half ago. Sorry I forgot to include that info.

I too think they are dead then, since they were recently transplanted.

David, from personal experience and from actually having been in the Maricopa/Phoenix area, i can tell you that kings do fine there. They are grown extensively in Southern California and the Phoenix area, both of which are dry as a bone. They also can take temperatures in the 20s when mature and if short in duration. There are mature specimens in the Central Vally of California (Sacramento, Modesto, Fresno, Bakersfield) that survived the Jan 2007 freeze with temps in the low 20s for about a week. My own seedlings last winter went through low 30s without missing a beat.

I would like to see the pictures of some sun grown or even shade kings in Maricopa / Phoenix Since they fry here at less than 100 degrees it would be interesting to see one after 105 or higher "average" summer temps.
Sacramento average is 89 to 94, Modesto the same and Fresno 91 to 97 Bakersfield the same as Fresno. Maricopa record low is 7 degrees and averages 34-35 while modesto record low is 18 the average is 39. I have seen seedlings take sub freezing temps better than full grown palms also.I would love to see picture of the surviving palms after that freeze that would be very interesting. Here palms do not take those temps at all because they rarely see it and never for days.This is a very interesting subject to me and hope to see the pics. I also love to be proven wrong about where they will survive because I am trying many myself that are considered not cold hardy enough but I keep trying.

When they get that dried out looking they are through... sorry

David,
I don't have personal pictures of palms in Phoenix, but i can tell you that i have seen king palms there. Also keep in mind that king palms are fast growers. You can get one over your head in 5 years or less. And the really cold temps out here happen about once in a decade (1998 and 2007 happen to be the two latest freezes). All that to say that you could get a king palm to a rather good size before the next big freeze wipes them out. So although the record low is 7 degrees, it could be a very long time before they see temperatures even near that.

Jungle music says although kings are not recommended for phoenix, they do grow there in the best of microclimates.
http://www.junglemusic.net/palmadvice/palmtrees-desertpalms.htm

And here are some links to photos that other palm growers in the central valley have posted on palmtalk.org:

http://www.palmtalk.org/forum/index.php?showtopic=14967&hl=

http://www.palmtalk.org/forum/index.php?showtopic=13572&hl=

http://www.palmtalk.org/forum/index.php?showtopic=2997

I hate giving up on palms if I think there's still a chance. In the closest bucket the palm on the upper right still has an emerging lush green spear... which is all the hope I would need to give it a while longer. The other 2 in the closest bucket look ragid and almost straw like. I wouldn't give them much longer. The seedlings in the far bucket still have some green even though they look rough. If you give them all enough warmth, light, and don't over water some may make it. However, if during your transplant you cut off too much of the main root they will probably die.

I live in Maricopa, AZ. Winter temps at night have moderated over the years due to the explosive growth of the town. Where as you could count on a hard freeze every year by mid January, now it just doesn't happen. Having said that, we are in an area filled with citrus groves and trees that do well, so this place doesn't really get as cold as many think. The record low temp of 7 was eons ago and is disputed since no town in the Phoenix area has ever been that cold, and that temperature will never ever be reached again. My backyard is full of tropicals. I have a lush shade tree - Tipuana, it's a tropical from south america and doesn't do well at temps below 30, it stays green all year round. As for palms, well - almost anything will do ok here if you take the right precautions for palms that need some extra care. I have a friend who has a dwarf coconut palm in a huge planter near the side of his house - it's doing just fine. I've seen many people put King palms in planters and they do just fine. I have banana in my yard, citrus, - the severe cold snap of Jan. 2007 did some damage, but nothing too bad... our coldest years are behind us as far as record lows, even Maricopa has started generating it's own heat island, and we're only 15 miles out from the huge Phoenix metro urban heat island. I've not recorded a temperature lower than 26 ever in my yard... and that was only twice. Past couple winters nothing below 34. Even those temps are of very short duration. Unfortunately, I have recorded temps above 118 every year since 1997. Again, given the proper care/shade/water - almost anything will do well. I am buying a King palm from the Target nursery today, I will put in a planter as it's only a small 5 gallon, it will go in a nice planter under the Tipu tree... can't wait to see how it does!

I personally agree with david these kings will not ever do anything It's either the sun or the lack of humidity i would consider them goners.