I have a 40 year old 28' windmill palm that hasn't recovered from the 2018 freeze in Virginia.  I lost some other windmills, but this one is in a more sheltered location.  The emerging leaves are small - maybe 1/2 to 2/3 the size of the healthy leaves it had before the freeze.  It only puts out 2 or 3 a year.  I'm afraid it's just too tall to recover.  I've tried foliar feeding.  I hate to just cut it, so I'll leave it as long as there is some green at the top; but I'm hoping that some of the experts on here can come to the rescue.

 

I recently tried some diluted hydrogen peroxide too.  No effect so far.

As long as the new spears are green and still emerging, I think I'd just make sure it's well watered and wait.  It may take even more time to recover or repair what was damaged.  There is a big one planted in the last few years out on a farm near me and it looks like yours.  I think they planted it and never bothered to water it, the one beside it died the first summer.  It's slowly but surely gaining more green.

I wouldn't say I'm an expert and this is no expert advice, but in this case I would simply start fertilizing it more frequently (I use a good granular fertilzer dissolved in water) and see if anything changes.

 

I would fertilize it with a good palm fertilizer and do a soil test.  I would check for healthy white roots by test digging a couple small holes about 15-18" from trunk and about 6-8" down.  Is this area dominated by invasive tree roots from large trees?  Is soil around palm generally moist?

Cut all the trees down so it gets more sun.

Thanks for the replies.  There is another trachycarpus right next to it that is doing great, and they are pretty far away from the trees.  They get about half a day  of sun.  I will explore the options that people have recommended.