Drip Irrigation Setup
Layout, timer, and emitter math.
Drip irrigation uses 30 to 50% less water than overhead spray, and it delivers that water exactly where roots want it. The setup looks intimidating from the catalog — in practice it is plumbing for children.
A residential drip system has four parts: a backflow preventer at the spigot, a pressure regulator (typically 25 psi for drip), a filter, and the distribution tubing with emitters. Total cost for a typical 1,000 square foot bed is $80 to $200.
Distribution tubing: half-inch polyethylene tubing is the workhorse mainline. Run it along the perimeter of each bed, then branch with quarter-inch tubing to each plant or zone.
Emitter math: most perennials want 1 gallon-per-hour emitters, two per plant for plants larger than one gallon. Shrubs and small trees want 2 GPH emitters, two to four per plant. New trees want 4 GPH emitters, four to six per tree for the first three years.
Run time: a typical zone in summer wants 60 to 90 minutes, two to three times a week, for the first growing season. After establishment, drop to once a week, then taper based on plant response.
Timer: a battery-powered hose-bib timer is sufficient for a residential property. Programmable models cost $40 to $80 and pay for themselves the first season in water savings. The single best feature is a rain delay button.