A topic from AEG's L5R CCG Rules forum, copied for Oracle of the Void from a copy of the forum saved in October 2015, so pages it didn't save are missing. Players' names are left out; the rules officials are named. Rulings are as they stood on these dates; later rulings, the rulebooks and the Rules Archive may differ.
A player, 12 January 2014
Will Jade Mine straighten itself after the action phase or does it stay bowed for the entire phase the turn after it produces 3 gold?
Jade Mine 2 Jade • Mine w: Produce 2 Gold. w: Produce 3 Gold. This Holding will not straighten until after your next Action Phase.
Jon Palmer (rules official), 12 January 2014
Will Jade Mine straighten itself after the action phase or does it stay bowed for the entire phase the turn after it produces 3 gold?
Jade Mine 2 Jade • Mine w: Produce 2 Gold. w: Produce 3 Gold. This Holding will not straighten until after your next Action Phase.
"Will not straighten" simply sets a prevention effect that keeps it from straightening. You would still need an effect to straighten it prior to the beginning of your next turn.