When to HARVEST in Southern Nevada Desert aka LAS VEGAS

I started a plant outdoors in the vegetable garden on May 5th, only one survived, Luckily a female. She is about 3 feet tall and has several bud stalks reaching upward. This is my first plant on my own and I am unsure as to when the best time to harvest is. It is so tempting to go pull her now but I want her to be the tastiest as possible! I have including a few current pictures, hopefully you can give me some advice as to when I should harvest. Is there any way to know for sure ... exactly when to do it?? :cool:

Ya man , you have to check the plants trichomes to know fer sure. I got a mocroscore at radio shack for 11 bucks to check mine. Trichomes are the little crystals you see on the small leaves and on the buds. That's the only way I know to check for the ripeness. When she's done the trichomes will turn brownish, when they turn 70 percent brown she's ripe and ready to harvest.