How Long Should You Water Your Lawn When Grass Seed Has Been Sowed?

Germinating Seed

• Seeds act as miniature storage units and will hold plants in a state of dormancy until conditions become right for germination. Germination begins with the absorption of large amounts of water, so watering your new lawn well immediately after seeding is a necessary step to beginning the growth process.

  After sowing the grass seed, keep the seeds consistently moist so that germination can begin. Give the seed a heavy initial watering immediately after sowing, until the soil glistens and the moisture reaches to a depth of 1/2 inch. The seeds should begin to germinate in five to 10 days, and during that time, you should irrigate two to four times per day, applying water until the soil begins to glisten. As time progresses, you will need to water for shorter durations to arrive at this point. Take care not to over water, however; if you see puddles of standing water after irrigation, you've overdone it.

Mulching

• To help keep the seed moist, lay down a straw mulch after watering for the first time. This mulch will prevent water from evaporating and will reduce the amount of water you need to apply during irrigation. Once the seed germinates, leave the mulch in place, as raking it up can damage the young seedlings.

After Germination

• Once you observe consistent greening over the seedbed, you no longer need to water as frequently, as you're no longer trying to spur germination. Begin gradually reducing the number of times you irrigate the new lawn per day. By the end of two weeks, you should be irrigating only once per day. As the seedlings become established and begin to develop roots, however, deeper waterings become essential. Ensure that water reaches at least to a depth of 1 inch while watering.

Toward Maturity

• As your lawn continues to grow and mature, continue reducing the frequency of waterings but continue watering deeply. During the third week, water every other day, then every third day. By the end of the fourth week, aim to irrigate only once or twice per week. Use the weather to guide your irrigation decisions. During consistently hot, dry weather, you will need to irrigate more frequently; during rainy weather, you may be able to avoid irrigation altogether. Dig down an inch below the soil to check for moisture to assess the need for irrigation.

  After the fourth week, only water when the grass shows signs of moisture stress: blades take on a bluish cast, you can see your footprints in the lawn and leaves show signs of wilting.