"Grass" is a poem written by Carl Sandburg and "Spring" by Edna St. Vincent Millay. Both poems are similar since they examine the theme of the conspiracy of nature in forgetfulness.
In "Grass", Sandburg explores that theme by presenting the cleaning effect of nature. Nature washes away the effects caused by man and wars. The grass covers the rests that the war had left on the land. Thus, there is no way of remembering the war.
In "Spring", Millay develops said theme by explaining that spring symbolizes a rebirth, a new life. But Millay explains that spring tries to compensate for the existence of death. In this way, nature's conspiracy to forget death is presented.