June 7th Sunday’s Boston Globe had an article blaming water overuse to lawn watering. The most egregious offense mentioned in the article was “You can be out in a downpour and the sprinklers are on – it’s frustrating,” . While I agree that lawns and automatic sprinkler systems can be at the root of the overuse problem it is not for the reasons outlined.
It has been my experience that the overuse of water related to our lawns is that we water too frequently and for too short a period of time. As a result, the water used is truly being wasted. When we first come on a property and check their irrigation system nine times out of ten we find that it is set to run three times a day (morning, mid-day and late day), for fifteen – twenty minutes at a time. So in essence by using an automatic system one is watering 45 – 60 minutes per day, seven days a week. In reality if one did that just one day a week their lawn would receive a good soaking. However, they would also need to change from watering three times a day back to watering only once per day.
It is also important to realize that watering needs change depending on time of season and what you are hoping to accomplish.
New Lawns - As I’ve stated elsewhere, the best time to start a lawn from scratch is the fall. While most folks want to start a new lawn as soon as the snow disappears in the spring; such an approach is not the best. If you are fortunate enough to get the lawn started; then you need to keep it going through the heat of the summer. This naturally will require greater water usage than if one waited until late-summer or early-fall to begin.
Over-seeded Areas – Water twice a day for approximately 10 – 15 minutes, mid morning & afternoon, to ensure soil and seed stay moist – not wet. Maintain watering schedule until seed germinates, approximately two – three weeks. Once the seed germinates, cut back watering to once per day in the morning, then every other day, then twice per week as the root system gets establishes. Once germination is complete you need to water 1 inch weekly to maintain a healthy lawn. Grass can take up to 18 months to become fully established. Avoid watering late in the day. During times of excessive heat more frequent watering is required. Mow at 3-3 ½ inches to shade the soil and hold in moisture for the new seedlings.
Lawns do not need to be green all season long. If you have a healthy established lawn it is ok and in fact natural for the lawn to go dormant in the heat of the summer. It will return in late summer – early fall as nights get cooler, dew will collect on the lawn and the early morning and the lawn will come out of dormancy.