The trees are coming into leaf
Like something almost being said;
The recent buds relax and spread,
Their greenness is a kind of grief.
This is the poem I think of every spring when the trees first start to turn green. I’ve only quoted the first verse here, but it’s worth following the link and reading the whole thing, if only because it ends on an unusually (for Larkin) optimistic note. There’s also a recording of the poet reading his own poem, which I always find interesting.