Trying outdoor for the first time.

So I put 2 white rhino's outside in early april when we we're getting 13 hours of light and thought they would do fine. Started to LST them but they started to flower. Currently they get almost 14 hours of sunlight which is why i wonder why they started to flower. Did I put them outside too early?

Anyone with some advice? When do you nor cal growers plant your seedlings?