Two doses of nectar.
Nectar is used to turn Pikmin from leaf or bud stages and into the flower stage. There are numerous places where nectar is found; Eggs, the bugs in the Wistful Wild, Flint Beetle family members, Nectar Weed patches, piles of rocky Rubble, Mitites, Honeywisps, and yellow Unmarked Spectralids can all drop globs of nectar.
There is a phenomenon that occurs if a drop of nectar, such as one from a petrified enemy, falls on top of a pile of sticks used to build a bridge (for example, the Cloaking Burrow-nit next to the bridge in the Wistful Wild should work if it stays close to the log pile). If the sticks are removed from under the drop by building the bridge, the drop will remain suspended in the air. Pikmin can be made to drink the nectar by throwing them at it, and they will fall back to the ground once the nectar is all used up.
Nectar