When the mud of early spring firms up in North Attleborough and the first bold green rises along the old jewelry-district streets, Dasilva Landscaping is already out with the mowers, following the season as it turns toward summer. There is a plain, honest beauty in a lawn cut clean and level — the stripes running true toward the woods that fringe this Bristol County town, the fresh-cut smell hanging in the warm river-valley light. Across the rolling ground near the Ten Mile River and the shaded yards of the mill-town neighborhoods, they tend the grass week by week, keeping pace as the long green months deepen. It is patient, satisfying work, the kind that lets a yard hold its shape all season and greets you, trim and settled, every time you pull into the drive.