If you have ever written a poem before, then you must understand that you must allow your imagination to grow wings and take flight.
A poem, no matter how descriptive it may be, is not to be used to state the obvious. We all know that the grass is green, for example. What you need to express in your poem is what you felt when you saw the green grass.
What emotions did it evoke within you?
What were you going through at the time and how did seeing the green grass change or enhance your feelings at that moment of time?