Hydroseeding is a planting process that uses a slurry of seed, mulch ( either recycled paper or wood) mixed with water that is sprayed onto your chosen site using a hydroseeding machine. It is often used as an erosion control technique on construction sites and as an alternative to the traditional process of broadcasting or sowing dry seed. Hydroseeding can be a very cost-effective way to begin a new turf lawn or to rehab an existing lawn. Many homeowners prefer hydroseeding over installing sod due to the lower price of hydroseeding per square foot. Hydroseeding is also an excellent way to overseed your current turf area. 
How much does it cost? prices can start as low as 7 cents per foot for very larger areas, but with so many variables, for example; the type of seed being used, type of mulch, and fertilizers not to mention the cost of getting a large truck to Your Jobsite costs can vary greatly.