kinda takin on alot for a first time grow eh? well just be careful, if they find your plot, its pretty easy to catch yuh considering...it sounds like your on an island...
50 plants in a 30sq ft area is a lot to have. and being on an island by a lake in NC.. dont think so. Space them out more, dont plant in rows.
Germinate indoors and let them veg for a few weeks before planting them at the beginning of Spring. Spring and summer have longer days, great for vegging, while the colder fall will have shorter and shorter days, which triggers the plant into budding and flowering. Thats how Cannabis evolved.