Question
QUESTION: I have a number of young evergreen plants and many Althea young plants in i gal. plastic bags. What would you suggest to protect them over winter besides using bales of hay?

ANSWER: Hi Louis,
Thanx for your question.  Where are you located?
thx,
Tom

---------- FOLLOW-UP ----------

QUESTION: Sorry. I should have mentioned my zone: zone 6, Waterloo, NY

Answer
Hi Louis,
Thanx for the additional information.  You can store the althea (are these Hibiscus syriacus - Rose of Sharon?) if they are rated as hardy to zone 5, in an unheated garage or cellar.  They will be dormant so they won't require sunlight.  The evergreens should be potted and moved out of direct contact from cold north winds.  Usually, behind a wall or on the south side of a house or building will be enough protection.  I know you can leave unpotted trees and shrubs in bags but these will require mulching with hay or some other kind of mulch to protect the roots.  If you don't want to do that then the best approach in my opinion is as stated above.  I hope this helps.
Tom