Indoor Plant Care - How to Houseplant Care

I recently received this comment/question from a  PlantAndFlowerInfo.com  reader. I have an email form for questions and comments, but often there is no return email address so I will post them here with my best answer and others may have additional information to add. Thanks Florida reader, I hope this helps! Palm Rhapis excelsa Question:  Four months ago, I relocated within  Central Florida . I uprooted some of my 10'-12' tall Rhapis excelsa palms to take with me & potted them in 24" wide pots, using Miracle Gro's Moisture Control Potting Soil. I planted 12 plants, at a rate of 4 per pot. Unfortunately, they didn't do well during the move & only 4(in 1 pot) seem to have survived. The others wilted & seem to be rotting from the top down, though 5'-7' of each trunk from the ground up are still green. I cut off the dead fronds and there's been no new growth from the tips, which are now rotted. What can I do to try to save them? Please...