Topping vs fimming
Topping
  • Cut the apical tip cleanly above a node
  • Produces 2 new tops
  • Predictable, surgical
Fimming (FIM)
  • Pinch / cut ~75% of the apical tip — leave a stub
  • Often produces 3–4 new tops (sometimes more)
  • Less predictable, less stress
Should I top autoflowers?+
Only if you have a long-finishing strain (10+ weeks). Otherwise, stick to LST.
When is too late to top?+
Once you've flipped to 12/12, leave the apex alone.