Aqueminianswered grow question 3 years ago If your growing an XXL strain it could be awhile before it flowers. XXL Autoflowers get big and means they have a longer vegetation time. You'll get good yields on that strain, be patient. You chose a longer growing strain. In my opinion, good choice, you could try doing a 12/12 light cycle to try to get it to switch but Autoflowers just do what they want.