FIM (named from the grower joke "f*** I missed", from an attempt at topping that left part of the tip) is a technique where roughly 70-80% of the newest shoot at the very top is pinched or cut off, leaving a small part of the growing tip. The damaged tip often regrows as three or four shoots rather than the two from a clean top.
In practice
FIM is done on the newest, still-folded growth, not the stem below it. Results are inconsistent: sometimes four tops, sometimes one or two, sometimes a stunted cluster. It recovers faster than topping because less tissue is removed, and the plant keeps more height. Many growers combine FIM with LST to spread the new tops out.
Evidence for FIM is almost entirely grower experience; there are no controlled cannabis trials comparing it with topping.
Don't confuse with
- Topping: a clean cut through the stem above a node; reliably gives two tops.
- Pinching (other crops): a general term; in cannabis it usually means topping or FIM.
