Starting a lawn from seed is less expensive than rolling out sod, but the new grass requires more care to become established. The process should begin with a soil test to find out how much organic matter and nutrients you need to ad and whether or not the pH needs to be adjusted. Adding fertilizer and planting the seed are usually separate steps, though some products combine the two for easy application.
Each of the many grass seed varieties has its advantages and disadvantages. Some prefer cool climates, some warm temperatures. Some grow well in part shade, some need full sun. Your local cooperative extension service can give you advice on the best types to grow in your climate, often a mixture of several grasses that adapt well to local conditions. Sowing seed that is not specifically recommended for your area is likely to be a waste of your time and money. The best seed is always the type that grows well in your area.
Fertilizer Selection and Application
The best fertilizer is also one that best suits your climate and soil type. Some soils are high in phosphorous or potassium, others are lacking. A soil test is your best guide to the type of fertilizer your lawn will need.
Because phosphorous and potassium move through the soil slowly, they are best tilled into the ground as you prepare it for seeding. Nitrogen, on the other, leaches out easily from the root zone, so it is best applied to the surface when you sow seed.
Apply regular lawn fertilizer when the grass seedlings are about 2 inches tall, using a product suitable for your local conditions.
Various products combine grass seed with a fertilizer and some type of moisture-holding material that acts as a mulch to prevent the seedlings from drying out before they become established. While these reduce the work involved in seeding, they may not be the best option. These products tend to have fewer grass varieties, which may not be the best ones for your conditions. In addition, the phosphorous and potassium stays on the surface, and doesn't get to the root zone.
Hydroseeding is a method of starting a new lawn by spraying a mixture of seed, water, fertilizer and mulch over the surface. It's a fast way to cover large areas or steep hillsides, but also has drawbacks. A professional needs to do it, increasing the cost, and, because the seed may not have close contact with the soil, the seed will need frequent watering.
Avoid fertilizing with "weed and feed" products when you're establishing a new lawn or sowing lawn seed. These products contain herbicides that can kill germinating grass seeds. You can use herbicides to clear the ground of weeds before seeding if you choose a product that does not persist in the soil.