Seed germination time depends on a variety of factors, including the amount of sunlight and moisture in the area. If you plant grass seed during a dry period, the amount of water you give it will affect the germination time. On the other hand, too much water can deprive the soil of the oxygen needed to make the grass grow. Keep in mind rainwater helps grass grow better than tap water. Spreading mulch also helps the soil maintain moisture. Make sure you select the correct seed for the amount of shade the grassy area will receive.
Sow the grass at the correct time of the year. As a general rule, the best time to plant grass seed is after the last frost in the spring, or in the early fall when it has enough time to take hold before cold weather comes to the area. Cool-season grasses grow better in lower temperatures. Warm-season grasses do not grow as well in cooler temperatures. Cool-season varieties such at ryegrass also are planted in the winter in Southern states to green up a lawn when the existing warm-weather grass is dormant. The cool-season grass then dies during the summer while the warm-weather grass thrives. Avoid planting grass in the late fall in cool-season areas when the temperature drops lower than 65 degrees,
If you buy inexpensive seed, there's a good chance it will not germinate as quickly. Seed usually is not a big expense, so don't skimp on it. Although annual seed usually germinates more quickly than perennial seed and provides a quick cover, it lasts only one year. As a result, you will have to sow the lawn again after the annual grass dies. Check the label on a bag of grass seed to see its germination rate. A germination rate of 90 to 95 percent is preferable. If the label says the germination rate is 90 percent, this means 90 out of 100 seeds should grow.
Among the fastest-germinating grasses are bent grass, tall fescue, ryegrasses and creeping red fescue. All of these are cool-season grasses. Bent grass, which spreads with creeping stolons, germinates in 10 to 14 days. Tall fescue germinates between a week to 10 days and has the added benefit of adapting to different kinds of soils. Rye grass seed can establish itself in as little as five days. Keep in mind that rye grasses come in both annual and perennial varieties. Creeping red fescue generally germinates in one and two weeks.