A well-designed irrigation system is the part of a garden nobody notices when it works. The lawn stays even, the hydrangeas hold their color through August, and the bluestone stays clean because no head is spraying it. When a system is poorly planned, the signs show up quickly: brown crescents between heads, soggy beds along the foundation, and a water bill that climbs every summer. Most of these problems trace back to decisions made before the first trench is dug. For homeow