dew at night with marine layer most of day. ?s

[JAHGYDI]

should i put a plastic cover on top? wont beable to do around sides just top. down here in socal im on the coast and weve been having a real knarley marine layer. the problem is its not burning off to let my plants dry off from the dew we get at night. i already started staking up branches and spraying green cure. dont want any moldy medicine.