I am sorry for this delayed reply to your gardening question. The spring rush has brought a deluge of questions and we are working hard to catch up!
Your palm trees just need time now to see if they can recover and resume normal growth. There is nothing for you to do but to provide adequate watering. Try applying some SulPoMag or Potassium Magnesium Sulfate. Sprinkle 1/2 cup evenly throughout a circular area extending 4 feet out from the trunk in all directions and then water it in well. See if they respond in a few weeks and if they do repeat the application twice more about 3 months apart.
Thanks for the question. Best wishes for a wonderful gardening season. Please stop in again soon!
Q&A Library Searching Tips