ya it seems every one who does a green house grow runs out of room for some reason mabye they just dent expect the huge plants, i just want a green house for regular garden plants and certain flowers and what not, if i grew weed outside i would just say screw the green house and put them right out in the sun
The only problem with that, is now you're more exposed to animals, insects, & enviornmental conditions. I'm helping a lot of OR growers who are posting under 'problems' that they are currently experiencing bud rot with all this moisture lately, and the fact that it's been much cooler & overcast means that your buds will not dry anywhere near what they would if it rained and the sun came out and it was 85 degrees. So that's a big risk right there. And then a as an extra precaution, I think my favorite part about the GH is my ability to run a dehumidier & hepa air filter any time I have it shut (approx 16 hours a day). This allows me to keep the humidity down to 60%, purify the air, and then the heat created by the electronics actually helps quite a bit at night, as instead of seeing 20 degree plus temperature drops every night, I'm able to keep the temps between 70-75 degrees at all times. Cutting out that temp drop makes a big difference on the plants and cuts out a huge potential stress factor. All that, plus the point you made about surrounding hemp growers or newbies who have males/hermies in the back that could potentially pollinate another growers all female garden (a greenhouse greatly reduces these chances if there is a surrounding grow of that sort) make this a huge insurance policy for your plants.
As for putting flowers & garden plants in there, it'd work great for that! You can put shelves & racks in there if you're doing that type of setup. My problem is when I was forced due to limitations to cut down on GH size, it prevented me from doing two longer rows and had to create the third. This is part of the reason why I didn't anticipate this kind of spacing originally, then just made do with what I had.