The lyrics are from this song (lyrics are in tab in the main info box.)
I am pretty sure that 秘めた想い預けて = 秘めた想い[を]預けて in this context. But I'm not so sure how to understand the lyrics as a whole.
Should I be understanding them as 桜[...][に] / 秘めた想い[を]預けて = "I leave my hidden thoughts in the care of the cherry blossoms"? Or am I completely off about this?