How does one "flower a starplant" ?

[RedTree]

I can't figure out how to make the starplants "flower" for the achievment

[Steve]

finish putting all of the star shoots into the energy rocks (Star shoots are growing out of the side of the star plants, and energy rocks are the bright yellow rocks)

[Specific Beef]

Not just bright yellow though. Each star plant has energy rocks of a different colour. Just look for glowing massive lumps of crystal on the underside of floating islands, and aim for those islands with the guided branches.