Not a good idea to treat with copper fungicide as a preventive measure. copper fungicides can be toxic to a palm tree and you only want to treat when absolutely necessary. Depending on what you want you want to treat for , there are gentler solutions out there.

What's your plan for winter? Are you going to try anything in the ground.

I use Propiconazale (systemic fungicide) which I buy from Bonide (named Infuse).

Since its systemic, it makes the plant toxic to fungus.

Copper is poisonous when too much is used so I would use it only to treat a large problem.

OK thank you for the info guys.
I don't have any palms in the ground OP, and figured that it was to late to plant.
I was just going to over winter everything with my other plants I was going put
in a garage greenhouse.

sounds like a good plan. what are you using for artificial lighting in the garage?

Well I think I am now going to put everything in my basement and use an East window and South window for light along with a 6 bulb T5 unit. After figuring out the cost for a 1000W HID system and light mover it was more than I really wanted to spend. It should be fun beacuse I am going to be laying tile in the same area this winter, so I will have to move plants about a dozen times too, lol.