What does this poem by philip larkin mean?

Hey guys,
Im doing some work on Philip Larkin at the moment and Im stuck on one of his poems. Its called 'Cut Grass', some of you may no it. If not here it is.

Cut grass lies frail:
Brief is the breath
Mown stalks exhale.
Long, long the death

It dies in the white hours
Of young-leafed June
With chestnut flowers,
With hedges snowlike strewn,

White lilac bowed,
Lost lanes of Queen Anne's lace,
And that high-builded cloud
Moving at summer's pace.

What I'm stuck on is annotating it. I've looked online and half the people say its about death and half say the beauty of life. Is it one or the other or both?! Also the line 'Its dies in white hours' does any one know what that means? Any help I can get on any parts would be much appreciated!
Cheers! xXx

Im pretty sure is about both like life sux but its has its good times