The Flowering Stretch: Managing Weeks 1-3 of 12/12
By The Budometry TeamPublished Updated
In the first two to three weeks of 12/12, most photoperiod plants stretch 50-100% taller. Planning for it is the difference between an even canopy and burnt tops.
Part of our pillar guide: Cannabis Grow Lights: Sizing, Height and Schedules
Flip at the right height
As a rule, flip when plants are roughly one third to one half of your maximum usable height. In a 6-foot tent with a light and filter hanging, that usually means flipping around 18-24 inches tall.
Control it with training, not stress
Low-stress training and a scrog net applied during the first two weeks of flower spreads the stretch horizontally. Once buds start forming, stop bending — the stems have lignified and will snap.
Raise the light on schedule
Check the gap between the fixture and the tallest cola every two or three days during the stretch. Tops that were 20 inches away on Monday can be 14 inches away by Friday.
Frequently asked questions
- Do sativas stretch more?
- Generally yes, often doubling or more, while indica-dominant plants may add only 25-50%.
The full guide on this topic
Cannabis Grow Lights: Sizing, Height and Schedules
How to size an LED to your tent, set hanging height by stage, run 18/6 and 12/12 on a timer, and hit the PPFD and DLI numbers that actually grow flower.