Mark Kvitko's explanation of Milk Grass:

The frustration is reflected in the character's relationship with his girlfriend. He appears discontent, unfulfilled, in an insatiable manner, lacking the force to appreciate what he has.

His return also was in a very large increment influenced by the fact he had felt that his father was dead. It is reflected in the dreams of the character in Berlin.

An expression that 'once a man's father is dead, he matures fully' in the metaphorical and literal sense is the case of the main character. He is from now the owner of the house and the head of the family. The final scene with the image of a man coloring the grass in white in the backyard describe the psychological state of the main character, resembling his held near and dear memory of milk grass, which he remembers from the funeral day of his mother.

However, now the grass is literaly olored in paint, there is nothing that is tender or poetic about it. It is not the image of milk grass. The final shot was also meant to reflect the political and social catastrophe (reference to Russian soldiers often coloring the grass in green with executives giving meaningless orders to eliminate critical thinking and avoid giving explanations), and his new responsibility that came with full manhood.

Maybe, not everything worked in the end, because explained before are underlying ideas and backgrounds for the characters, which I needed for a full proper story in my head. Showing everything in the film would make it uninteresting.