No Sword Fighting in the House by Susanna Leonard Hill, True Kelley
Charge! Arthur and Lance are at it again, sword fighting in the house, that is. When Mom returns home, the boys are in trouble, big trouble. But that doesn't stop Arthur, who already has a new idea. He and Lance can joust, which isn't exactly against the rules, and at least they won't be in the house. Atop their strapping steers, they are ready to charge; but the cows won't move . . . until one of them spots Mom's tasty garden!