Bill Kreuser, Extension Turfgrass Specialist, University of Nebraska-Lincoln, writing in their Turf iNfo blog:
Sodding a lawn, field, or other turfgrass area can provide a rapid green carpet. Water management after the sod has been laid will impact the speed of establishment and health of the stand. The broad goal is to keep the sod from wilting (or dying) but not waste water, firm up the soil under the sod, and not weaken the turfgrass plants by over-watering. Here are some tips to achieve that goal.
· Water deeply immediately after the sod is laid to wet the subsoil. The goal is to wet the soil for the roots to access adequate moisture in the future. The sod on top of the soil will act as a barrier to prevent underlying soil from drying out. This means, heavy irrigation cycles aren’t needed in the week after the sod is laid.
· The turfgrass plants will only have short roots in the sod. That means the plant will have limited access to water during the day. As a result, light and frequent irrigation is required until the roots start to grow into the subsoil. The goal here is to only keep the sod wet, not to water the underlying soil. For example, sod can lose 0.3” of water during a bright, hot and windy day in August. If the sod is watered three times that day, then only 0.1” of water needs to be applied during each watering. On cloudy days, the amount required can be much less. Water should not be running off from the stand (a frequent sight around many newly sodded lawns).
· Start reducing irrigation frequency once the sod roots penetrate the underlying soil. This usually occurs a few days after the sod has been laid. Lightly pull up some corners to see if the roots are growing. Once you can no longer pull up a corner, move irrigation to once a day. Two-inch grass roots can sustain the plant’s need for water during one day. Still try to apply between 0.25 and 0.3 inches of water per day; less is needed if it rains or is cloudy.
· Continue to stretch out the irrigation interval as the roots continue to dive deeper into the soil.