Project Guide

Overseeding Your Lawn

  • Mow your lawn so that the grass sits above the soil line. Ideally, it should stand at an inch to an inch and a half. This will allow your grass seed to get adequate sunlight and connect with the soil. 
  • Next, use a thatch rake or power rake to remove any thatch that you find, a process called dethatching. 
  • Thatch is a spongy layer of dead organic matter mixed with living plant parts that can lead to disease and insect problems if not eradicated. A heavy layer of thatch can prevent your grass seeds from germinating. 
  • To dethatch, rake the lawn in one direction and give it another pass in the opposite direction. The tines on the rake will pull up the thatch along the way. Be sure to rake the thatch off the lawn when you’re done.
  • Another way to remove thatch is to aerate your lawn. This combs your grass and kicks out debris. It also loosens the soil so that air and water can reach the roots. Your grass seed will be able to grow faster and more robust. Lawns that are compacted due to heavy foot traffic should especially be aerated to produce efficient growth. 
  • A core aerator is a great tool for this job. You can rent one at your local Home Depot store. 
  • To operate the core aerator, move it across the lawn in straight lines until the yard is fully covered. Do a second pass perpendicular to the first one if needed. Make sure the core aerator pulls plugs of soil from the turf rather than simply punching holes in the ground. This helps to break up the compaction. Leave the plugs to dissolve on their own within a couple weeks.
  • If your lawn has bare areas, spot treat it with topsoil, which will improve the quality of the soil and allow the grass to grow. 
  • For areas with water drainage problems, typically where the grass doesn’t grow, apply a thin layer of sand over it and smooth it out with a rake. Sand allows the grass to germinate faster and it creates a thicker root zone.
  • Now you can spread your grass seeds evenly around the lawn using a broadcast spreader, drop spreader or hand spreader. Follow manufacturer’s instructions for distributing the seeds. 
  • Then, apply slow-release fertilizer that works best for your specific grass. Slow-release fertilizer provides nutrients to plants gradually, within three months in many cases. This will prevent you from over-fertilizing. 
  • Lightly water the lawn immediately after overseeding. Continue to water it frequently, about three to four times daily for the first several weeks to ensure proper germination. 
  • Once the grass is an inch tall, cut the frequency of watering back to once a day, but increase the duration of watering to 20 to 30 minutes per zone.
  • Continue to mow the grass to a height of two inches for the remainder of the season. Mow the lawn when the grass is dry. 
  • Fertilize the lawn about six weeks after you sow the seed. Apply a pound of quick-release nitrogen fertilizer for every thousand square feet of lawn space. 
  • If your lawn is 5,000 square feet, you would need five pounds of quick-release nitrogen fertilizer to treat it. The fertilizer should work for your specific grass type. Repeat this process in another six weeks.

Don't worry if you don't own all of the tools needed to overseed your lawn. Rent tools and trucks for any project at The Home Depot.