you can. i've planted in mid augast and harvested in the first few weeks of october before. the plants started to flower when they were only 6" tall. i only got about 2-5 grams off each plant. if they start out under 12-12 or close to it, they will start flowering as soon as they can. i do recomend that you let them get a good two months of flowering so they will be fully matured.