What is it?
Hydroseeding is really a pretty simple process. Water, seed, fertilizer and and a protective mulch is mixed in a tank and sprayed onto the ground. This process is more successful than standard seeding and will look better than Sod over time.
Water in the mix acts as a carrier, and the contact of the seed and the water will jump start the growth process. When extra fast germination is desired, it is also possible to pre-germinate seed for even faster growth.
Seed used in a hydro seeder doesn't need to be anything special. Nearly any seed can be used and at the same application rate as other seeding methods. These can include grass or lawn seeds, wildflowers, pasture seed, seed for athletic fields and seeds for erosion control such as crown vetch.
Fertilizer is usually used in the mix. A high phosphorus "starter" fertilizer that will stimulate root growth is the most commonly used.
Hydro seeding mulch is what gives it the green color. It does more than just make it pretty, it helps protect the seed, and to seal in moisture. It may be made from a paper or wood product or a mix. If any accidentally gets on your walkways, driveways or house, it will not stain and can be washed off, or will just disappear on it's own.