Why Hydromulch is better then sod:
The advantages of Hydromulch must be considered over sod when deciding what is best for your grass needs. Sod is simply fully grown grass attached to a bottom layer of soil. With sod there is little control over the blend of grass going into your lawn, shrinkage when lacking proper watering, and the sod not growing roots below the thin layer of soil. Sod has the highest watering needs of grass installation and also tends to be more expensive and labor intensive then Hydromulch.
Hydromulch is a liquid mixture blown through a sprayer over a large area. The liquid, referred to as slurry, is composed of grass seed, mulch, and other fertilizers. Hydromulched lawns will also typically come in faster. In fact, it is not unusual to see early growth in as little as five or six days.