There are 2 purposes why we need to overseed our lawns. Lawns are overseeded in cooler climates in order to repair damaged sod and to rejuvenate the lawn area with new growth, this can be done in both Spring and Fall. In warmer climates, Warm Season grasses are overseeded in the Fall with a Cool Season grass type to maintain a green lawn throughout the Winter when Warm Season lawns go dormant. The Cool Season grass then dies off once the weather warms up, and the Warm Season grass then once again becomes dominant, lush and green to keep the lawn looking its best.
Preparation For Overseeding
Good preparation will always ensure the greatest results from overseeding. To begin, the existing lawn should be mowed down as low as possible without risking damage to the grass.
A good quality organic top soil should then be applied and raked into and over the grass. The grass doesn't need to be smothered with the new soil but more of a thin layer added to improve the soil, improve it's water retention properties, and to give the grass seed a "bed" in which to best germinate.
Water the existing lawn each day for the next few days, ensuring a good, deep watering each time. This allows the new top soil to blend further into the lawn and remove any air pockets, it also moistens the existing soil in preparation for germinating the seed.
Overseeding The Lawn
Now all the essential preparation work has been done, we can begin the seeding process. Measure the area to re-seeded and prepare enough lawn seed as required by the seed variety for purposes of overseeding.
Spreaders should be calibrated from manufacturers instructions so they apply the correct amount of lawn seed required. Half the lawn seed in the spread on the lawn while walking in one direction. Once the first half of the seed is applied, we then spread the last half of the seed over the same area, but this time we walk in the opposite direction. This allows the greatest possible even coverage of seed.
Finally we will need to top dress once again. This is a very light top dressing, the seeds have no need to be buried, but a little soil on top will aid considerably in helping the soil keep the seeds moist for longer. Light top dressing considerably increases the chances of success for overseeding.
Lawn Care For A Newly Overseeded Lawn
Finally, once all our hard work is finished and our lawn is successfully overseeded, it's time to look after it to ensure the seed germinates and take hold to give the nest results
Newly seeded lawn should never dry out, ensure the soil and seed is kept moist at all times by watering several times a day dependant on weather conditions, and always carefully monitoring the soil moisture levels.
All foot traffic should be stopped to the area during its establishment, and wear and tear will easily damage and kill any new grass shoots. Once established, light foot traffic can be slowly reintroduced.
Once the reseeding has fully taken hold and the area is repaired and thriving, we can now look at reducing watering. It's important not to suddenly stop a highly regular watering regimen, instead - slowly reduce the number of waterings while increasing watering times. The main aim here is to train the lawn to grow with a deep root system and with less water for it's long term health.