Spring is arriving, and the poem catches it in quick, physical snapshots rather than big statements. Wind presses down the fresh green ground, buds begin to mark the thorn bush, and new seed is scattered about, spiky as tiny porcupine quills. Then the focus shifts to a "mounting kick" that fizzes in the air, which seems to be a ball or a rising energy, hard to say which. Schoolboys are out playing, and their sticks and stubs fly up. The line about the "old brown moon" suggests a worn ball that no longer gets dribbled along the little paths, since the game has grown louder and bigger.
The speaker mostly watches, but the delight shows in the playful, almost bouncing language: "frets and fizzes," "chivvy." The mood is lively, fresh and a little mischievous, with nature and children both bursting into motion. The final image, flowers nudging the stone, makes spring seem gently insistent.