In the area of my yard where I may set a gh there are 2 potential problems. 1. There is a streetlight about 100 ft away that shines on my house and reflects onto the area where the gh would be. Would that mess up the flowering cycle? 2. The area gets about 3 hours of direct sun per day, is that enough? There is no other area where I could do this. I also don't want the hassle of having to put black plastic over the gh every 12 hrs. Is a gh feasible then? BTW I tried to do a search before posting, but search function is FUBAR it seems.
This is not a very good place to grow for both reasons. Light pollution as little as 2 ft candles can inhibit or interrupt flower initiation in short day plants. You could check this if you have access to a light meter. Commercial greenhouses growing short day plants avoid this by pulling black curtains to control photoperiod and avoid light pollution. Three hours of sunlight a day is not enough for good growth. A minimum should be 4-5 hours of direct sunlight. You should look for other options if you can determine the light interruption is too bright and don't want to deal with curtains. If the light pollution is in acceptable levels and you can not prune plants back blocking light or if there is buildings causing the reduced light hours your grow will not be too successful with only 3 hours of light, although you may get a reduced harvest if lucky. This can be a major nuisance for growers of short day plants when there is a lot of extra lighting from other sources near the grow area.