On a June morning in Bedford the sprinklers come on before the sun clears the trees, and for an hour the lawns go silver. Urellas Irrigation & Landscaping, LLC tends that quiet machinery — irrigation installation, spring startups, head adjustments, midsummer repairs and blowouts before the ground locks up in November. The rest of the week is lawn work: mowing, trimming, edging, mulch, and the clearing that spring and autumn each demand. Water laid down evenly and grass cut at the right height do more for a yard than anything else, and the color tells you so. From the ravines around Pulpit Rock to the streets off Route 101, that is the work.