I was using storage to advance to the next level. I had two assets (oak trees) worth 80 flowered each...

Did you level up more than 1? When the number of flowers needed reaches 0, you should level up, as the red number next to your picture goes up 1. So you needed 65 to advance; 65 of the 80 flowers from the Oak tree went to level up 1x with the other 15 flowers used toward the next level, such that you only need 25 more for the next level. Once you put the 2nd Oak tree down, 25 went to the level up again, and now you need another 162 flowers for the subsequent level. As soon as you exit storage, the game will show you the higher level you have achieved. You should have one scene ready to play, and the next scene will be ready to play (no more flowers needed) as soon as you find the 2 story clues from the 1st scene.