where the new grassflames as it has flamedoften before (2-4)
That "Widow" in the title put us on high alert when it comes to death. We're looking for it just about everywhere in the poem. And lucky for us, it can be found just about everywhere, just subtly – like in these lines. Even though this grass is new, and growing well, it is described as a flame. Flames are, to put it frankly, deadly. In this poem, even growth and renewal are described in lethal terms.
with the cold firethat closes round me this year. (5-6)
These lines sound like a death to Shmoop. Even though our speaker is describing the outside world and the nature in her yard, her word choice is suspiciously morbid. When something closes, that's an end, right? We say "at close of day" and it means at the end of the day. Well, we can't read this line without the faint feeling that it's also describing the end of a life. A cold fire that closes around our speaker? It's enough to send shivers down our spines.
Thirty-five yearsI lived with my husband. (7-8)
This is a lot like the lines about the new life in spring. What we mean is, while on the surface she's talking about the time when her husband was alive, what it really seems to be telling us about is his death and her life without him now. Our speaker doesn't want to explicitly go there, but when she throws out a mention of her life with her husband and then goes on talking about her yard and her sorrow, it's not too difficult to connect the dots.