Those plants are way too close together. When you spot a male, don't yank him, you'll tear up the roots of the other plants... Just chop the stem off close to the ground. Seriously, if you can move them a foot or two apart they'll all be much better off, and you can keep them short and stocky by bending / tying stems/branches, aka L.S.T., as well as topping / pinching stems and branches, aka Supercropping. The extra space will also make it easier to remove males.

You need to protect them from critters... bugs, deer, rabbits, slugs & snails and all manner of creepy crawlies love our plants as much as we do.

Prodaytrader makes a few valid points but forgets that cannabis is an annual, meaning that once the plant senses the days getting shorter, it goes into flower in hopes of producing seed to reproduce, after which time it dies. (If humans weren't harvesting them first There'll be no year-long wait for a harvest... It's almost June 21st, aka the longest day of the year. After that, the days start to get shorter, and by early August you should definitely know how many girls you have. Harvest time outdoors is generally mid-October in the majority of the US, sooner or later depending on the typical date of first frost in your location.

My point being, if you get females, you will have buds. Potency is 80% genetics, 20% environment. The amount of bud you pull off each plant is about opposite, 20% genetics / 80% environment. By environment, I mean every variable, natural and man-made. Sun/shade patterns, pests/foraging animals, weather, amount of nutrients available in soil / given by you, how you top / train them, etc.

One more very important thing: NO PLUCKING FAN LEAVES!! EVER!

It's a lot of fun though, enjoy it and good luck to you for some healthy, pretty ladies.