The solution is 1 top-right, 2 bottom-left, 3 bottom-right, 4 top-left. The hint is "Stages of Growth" and the top-right is set to 1. To the right of the chest is a hole, to the bottom-left is tiny plant sprouts, to the bottom-right is a regular plant, and to the top-left is a withering plant. Don't feel dumb for missing it, I could've made it clearer visually.