How long have you grown all these different types of palms in your area? Also, how large are they curtently and how large were they when you planted them out? Would love to see pics of your palms!!!!
Here is a link for some folks that are not that familiar with hardy palms. Hope this helps people that want to grow palms and are not discouraged when they encounter problems with some of the above choices. I just have a hard time imagining some of these palms surviving with just mulch in my 7 a/b, much less your 6!
A quick reference to hardy palms:
SPS Hardy Palms: A Quick Reference
More detailed info on hardy palms:
http://www.sepalms.org/Hardy%20Palms...m%20Reader.pdf