On the surface, this is a short description of a neglected garden: roses, tulips, and daisies are being smothered by weeds, and the speaker can barely see the flowers anymore. But the garden feels like more than a garden. The speaker calls it "my garden," which makes the loss personal, and the phrase "pretty pieces of life that used to be free" hints at something bigger than plants. Judging by the language, the flowers could stand for joy, hope, or parts of the speaker's own life that are now being crowded out by worries or problems.
The mood is quiet and sad, with a note of helplessness. The speaker doesn't say they are pulling weeds or fighting back, only that the flowers "are being consumed." The short, plain lines and the lack of fuss make the loss feel matter-of-fact, as if the speaker is watching it happen and can't stop it. The closing rhyme of "see" and "free" lingers like a small, wistful sigh.