G13 is a strain that is crossed with several different kids of bud. I grow the Sour Mango x G13 x Haze that I got as a clone from the clinic here in the US. It flowers in 10-11 wks, if you want the full potential. I cut one down at 8 once, but the yield was lighter and the bud was far less resinous. You will probably have to wait at least 8 weeks for 90% of the strains out there, and if you want the G13 to produce big buds, you need to just allow her to tell you when she's done. Cheers