I planted my 15 gallon Copernicia Fallaensis out a couple weeks ago.  I had had a spear tip section 5" long rot a year ago.  I treated repeatedly with peroxide and daconil fungicide, put it in a full sun all day spot and now it has grown out of it.   So 11(?) days ago I planted it.  I find cuban copernicias in containers to be touchy, a little too much shade and you have some trouble.  The shade spots change in my yard a lot as the sun comes north in summer.  If I dont watch that sun exposure I