I'll add a magazine holder... 😆

😉 😀 😀 😀 😀 And Francko's "Palms won't grow here! 😉 😀 😀 😀 😀

Rubtherock

Your right the plastic would protect your Washys from frost build up but...........
22(F) is about as cold as they are going to take with just plastic without leaf damage.
Any colder and you can expect leaf damage anywhere the leaves touch plastic.
Hopefully you won't see much colder and you warm up during the day!

Dear, Rubtherock! Your zone looks like zone 9a. You grow the syagrus palms without any protection! In my country even in Crimea (zone 8b) the syagrus don't grow! This winter is typically winter for zone 7b.

This weather is more typical of Zone 5. My zip code is 28012 which puts me barely in zone 8 according to Arbor Day and Zone 7B according to all others.

It has been down to 14 degrees here for three nights in a row.

I've never grown any syagrus palms. My palms are windmills and European Palms which seem fine without protection, Queen Palms which I've mostly fried, Pindos and Washingtonia which I've protected, and of course the very cold hard need and sabal minors which also require no protection.