At Bell Rock the ledge pushes up through the grass beside slate stones that have been leaning there a very long while, and mowing around that has to be done by hand and by eye. High power masonry keeps lawns across Malden — cutting, trimming, edging, and the seasonal cleanups that take a yard from ragged to squared away. Ledge and roots run close to the surface in this part of the city, so the deck rides high and the trimmer does the finishing. Spring is the best of it: the first cut of the year on a yard already raked clean, when the green comes back all at once. What's wanted is simple and hard — an even lawn with a straight border.