Tips and advice?
Hi. Posting this for friends who have a very small family farm at home. Don't know where to put this new topic but Mrs or Mr Blown Dry will!

My friends were just given permission to grow dahlias on a large farm which has been neglected and overgrown. They don't have time to prep an outdoor place because their plot at home is already full of produce and other flowers. This season, they plan to use a huge hoop style greenhouse open at both ends for dahlia growing. I gave them some dahlia varieties which they potted in 1 gallon pots and which they intend to plant in the ground soon in this greenhouse, and use a fan or fans.

This means HOT and humid temps even with fans.. I don't think this huge commercial style greenhouse has any way to shade things, so I'm asking all you hot-climate dahlia growers to weigh in! We are in NW coastal WA so may be graced with a relatively cool summer, but we're already in drought out west with a super el nino predicted.

Is there some way to create shade as needed to keep dahlias cool and or shaded in the hottest, sunniest days - I imagine something that can be put on and removed, or...? It's night and day here temperature-wise when the sun is out or when it's cloudy. Today it's cloudy and quite cool. - jacket weather. When the sun is out it 's intensely hot, even in the upper 60s with mostly dry heat. I can only imagine dahlias will hate this and since they are getting a late start to plant in the ground, I thought I would ask here and get some expert advice. Shade cloth? Build a structure within the greenhouse or stake in a way to provide shade on an as needed basis? Would remay be enough or do they need actual shade cloth? Should they suck the hot air out with the fans rather than blow the air around inside which would seem to bring more hot air in? Is hot and dry what causes conditions for spider mites? (If so, I'll tell them about the molasses trick! Or better yet, get them to join this forum.)

Thanks for any and all advice! Mods, please feel free to move this to the proper area in the forum if this isn't it. Thanks!