A scraper assembly for removing mud and moist soil from the gauge wheels of an agricultural planter includes a support rod attached to a hub of a gauge wheel arm, a clamp structure attached to an end portion of the support rod, and a scraper blade attached to the clamp structure. An axis of the end portion of the support rod is approximately perpendicular to and intersects with an axis of rotation of the gauge wheel. The scraper blade is mounted approximately perpendicular to the outer surface of the gauge wheel and is angled approximately 45 degrees from the sides of the gauge wheel. The scraper blade has a curved profile along its length that substantially matches an outer profile of the outer surface of the gauge wheel when the scraper blade is properly adjusted.