I don't know the temp under the plastic. Ok so get rid of the plastic,what about the soaker hoses? Is it good to use those and if so how would you run them? If not what is the best way to water the melons? I read that overhead watering (sprinklers) was not recommended, or watering the foliage at all except for rain. They were doing great,about 2/3 way to harvest and then one by one started wilting. I appreciate all the advice,thanks