Grass seed watering- When watering new seed, Water 5 times per day, for 4 minutes at a time. When the seed reaches one inch tall new grass blades, it's time to fertilize with starter fertilizer. At this point, water 3 times a day for 10 minutes. After 6-8 days, back off the watering to twice a day for 12 minutes. Finally after 4 weeks, water one time per day for 12 minutes.