There are three hard and fast rules when it comes to establishing a grass lawn successfully from seed: Prepare a rich seed bed, keep it wet and keep off it. Consistently moist soil is needed for effective seed germination and root establishment. Leaving the seeds undisturbed by foot traffic and lawnmowers for an extended period will allow the roots to become well established, growing deep and knitting together to form a lush carpet.
A Well-Prepared Seed Bed
Seeding a lawn onto poorly prepared or unprepared soil is a waste of your time, grass seed and water. Though shoots may grow in an unprepared bed, the seed will struggle to produce a lush lawn that can be sustained over time. Till up the seed bed well to a depth of at least 3 inches. Remove any stones, plant roots and debris. Amend the soil with compost, well-aged manure and a lawn starter fertiliser. Work the amendments into the soil well and smooth to level with a rake. Seeding the lawn onto a slightly moistened seed bed will help the grass seed stick and nestle into the soil.
Grass seed requires constantly moist-to-wet soil from the moment it is sowed through its establishment phase. Sowing grass seed in the spring and fall helps to cut down on watering stress during germination with mild temperatures and skipping over the hottest heat and sun of summer. Water your newly sowed grass seed in the morning and in the evening to keep it moderately moist but not soaking wet. In dry or hot climates, a third midday watering may be required. Keep up the 2 to 3 times a day of short session watering schedule until the grass shoots reach 2 inches in height. At this point, you can scale back to once a day watering for a few weeks. At the fifth of sixth week you can scale back again to watering every 3 to 4 days. By the 10th week of growth, begin a maintenance watering schedule of 1 inch of water per week applied in one or two deep watering sessions.
Foot Traffic, Mowing and Fertilizing
Though green grass shoots can appear quickly and seem hardy, grass in its establishment phase is a delicate plant. The newly forming roots that will support the lawn over its useful life are growing deep to allow them to reach for nutrients and protect the lawn from drought. Any weight or disruption can create micro tears in the roots delaying their development. Plan to keep foot and paw traffic off the newly seeded grass for a period of at least 8 weeks and up to 12 weeks for slower-growing grass varietals. For this same reason, mowing the lawn for the first time should be held off until the grass blades are 3 inches or more in height or at least 8 weeks, whichever is longer. When you do mow for the first time, only remove a third of the blade length and continue to reduce the mower height, removing a third at a time in subsequent mowings until you reach the desired maintenance blade length. Also, hold off on fertilising your new lawn for at least 6 weeks to allow the roots to develop without forcing the plant energy to produce green blade top growth, which is what fertiliser produces.