Water daily for 2 weeks. The BIGGEST thing to remember with new seed is that once it gets wet for the first time it cannot dry out or the seed is Dead! You can’t re-wet it and expect it to pop back into growing. If it dries out before it starts producing the green grass and the root starts developing into the soil then it is totally dead!
It’s hard to give an exact amount of time as to how long you should water each time. You need to monitor it and adjust based on weather conditions, such as how hot it is that day, is it cool that day, is it sunny or cloudy, how much water does your sprinkler put out, etc…
The 1st and 2nd day are usually the days that you have to water the longest.Your goal is to get the soil saturated. Once the soil and seed are saturated then you just have to keep it damp. Usually by the 3rd week you can back off on watering some, but we still recommend paying attention to weather conditions and watering at least every other day. Even though you should have grass starting to come up by now that the roots are tiny and barely in the soil at this point. They can dry out extremely fast if we have a day or 2 in the 90’s. You may have to be moving sprinklers around the yard. Be careful not to walk back and forth over the same new grass over and over. Take a different route to the water spigot, and try to limit kid or pet activities on newly seeded areas.
If you have established grass that is growing faster than the new grass that is fine. If you have to mow you can. Reset your mowing height to 3 ½ to 4 inches. If you have minimal grass clippings you can leave them.However, if you have a lot of grass clippings you will want to remove them because they can smother the young, new grass.
Not long after seeding season we usually start to have trees drop their leaves. You don’t have to blow leaves off every time a new leaf falls, but it is a good idea to keep them cleared away from the new grass before they build up heavily. Something as simple as wet leaves sitting on the new grass for a few days can stunt it and if left longer can totally kill a section of grass.
Don’t add more grass seed. NCSU has one of the best turfgrass programs. They have done studies to find out how much seed should be used to get the best results when reseeding. We follow those recommendations. If you add too much seed to an area it may look good in the short term while the grass blades are really fine. But as the grass grows there is competition for root space, water needs and airflow. Ever had a good stand of grass in the fall when it is young and have it die out in the spring before warm temps even hit? Chances are there was too much seed planted. Now, I’m not saying there won’t be any need for touching up a few areas. We just don’t want the entire lawn hit heavier with seed. If you have areas that aren’t coming in after 2-3 weeks just throw a little touch up seed in those spots and keep it damp.