First month – Watering is the most critical factor for the rapid and healthy development of your lawn. To promote germination, the seed and young grass should not be allowed to dry out for the first three weeks after seeding. The lawn area should be kept moist but not saturated. A daily schedule consisting of a light watering early in the morning, a light misting in the early afternoon, and a second light misting in the later afternoon (especially during hot, dry weather) will help achieve this.
After first month – After the grass greens up and reaches a height of about 3″ (about 30 days), watering should be adjusted to approximately 35 – 45 minutes (rotary heads) every 2 days in Summer (in Spring and Fall every 3-4 days). ONCE THE GRASS HAS BEEN ESTABLISHED, DO NOT WATER EVERY DAY. This can lead to disease problems, drowning of roots, and weak root development. If the lawn is drying out in the summer heat, increase the time per zone rather than the number of watering days per week.
BEST TIME TO WATER – between 1 a.m. and 10 a.m.
WORST TIME TO WATER – between 4 p.m. and 1 p.m. (Fungus will develop and grow when the grass stays wet for more than 6 or 7 hours during the course of the night, so avoid the urge to water your lawn in the early evening.)
First mowing – About 30 days after seeding. TIMING IS CRITICAL. If the lawn gets too long it will fall over and mat down, leading to the development of disease. The lawn should not be watered within 24 hours of the first mowing so that the mower tires and workers’ feet don’t make ruts in the wet soil. Make sure to turn off your sprinkler clock the night before. The mowers should cut off no more than the top 1″ of the grass blades so that the grass will not go into shock. Resume normal watering after mowing.
The establishment of a healthy lawn from seed is a long-term process. Use of the seeded area should be limited as much as possible while the grass is getting established. Depending on the time of the year the seeding is done, it may take up to 12 months to reach the look of a sod lawn. The ideal time for seeding and touching up of seeded lawns is mid-August to mid- October. Avoid use of crabgrass control while the lawn is newly seeded.
Apply a complete fertilizer only after the lawn has been up for at least 30 days. Avoid fertilizers heavy in Nitrogen (the first number of the three that appear on the bag) for this first fertilization. An ideal balance would be in the range of 10-30-15 (as opposed to 25-3-3). After the initial fertilization, follow a May-August-Thanksgiving fertilization schedule (i.e. 3 applications per year). If you are a chemicals minimalist, then use an organic fertilizer and apply on Thanksgiving only, or again in July.