The answer to 'when to sprinkler system' is that the best time to install or activate a sprinkler system is typically in the spring, before the peak growing season. This ensures your lawn and plants have the water they need to thrive during the warmer months. Sprinkler systems should be turned on and checked for any necessary maintenance or repairs once the risk of freezing temperatures has passed, usually in April or May depending on your local climate.
It's important to have your sprinkler system inspected and tested annually to ensure it's operating efficiently and not wasting water. A professional landscaper or irrigation specialist can help you determine the optimal schedule for your system based on your specific needs and local weather patterns.