What is the best time of year to install a sprinkler system?

Best time of year to install a sprinkler system is early spring or fall, when ground is workable and landscaping disruption is minimal, and contractors are less busy than summer. Spring, March to May, is ideal because soil is soft from winter moisture, making trenching easier, temperatures are mild for workers, and you can have system ready for summer watering season to keep new lawns and plants healthy. Fall, September to November, is also excellent because contractors have more availability after summer rush, temperatures are cooler, grass and plants are dormant and less affected by digging, and soil is still workable before freezing, allowing system to be ready for next spring. Summer is possible but harder due to hard dry soil, heat for workers, and potential damage to actively growing lawn. Winter installation is difficult in cold climates due to frozen ground. So best time is early spring for immediate summer use, or fall for less busy contractors and less stress on landscape, avoiding extreme heat or frozen ground.