Overseeding your lawn: the secret ingredient

​When it comes to healthy, lush lawns, overseeding is a lot like the secret ingredient in grandpa’s famous rib sauce. You’ll make do without it, but it’s never quite as good as it could be. Unlike grandpa’s secret ingredient, there’s no coaxing or bribing here…just some simple facts to help you understand more about how and why it works.

What is overseeding?
Simply put, overseeding is when you spread grass seed over an existing lawn.  Depending on the condition of your lawn, you may want to topdress the soil with a thin layer of compost after spreading the seed to help the seeds germinate and give the seedlings added nutrients to help them thrive.
 
Should I overseed my lawn?
Unlike some other lawn care services, overseeding is recommended for every lawn — even the best conditioned ones. Fertilizing your lawn is important, but even the healthiest grass will slow down its rate of reproduction after a few years. Over time, lawns that haven’t been overseeded will grow thin and unhealthy, which also makes it easy for weeds to overtake the lawn.
 
By adding new grass seed to the existing lawn, you’re able to thicken areas that are thin and weak before they continue to worsen and cause more problems. You’re also replacing older, tired grass with healthy, robust grass that is more likely to require less water, less fertilizer, and less intervention to control weed growth.
 
When is the best time to overseed my lawn?
Spring and fall are usually the best times to plant grass seed because the temperatures of both the soil and air are warm, and natural rainfall is common. These are great conditions for optimal seed germination and for the seed to successfully establish contact with the soil.
 
Fall germination has a few added benefits, but spring is a close second:

• When seeding in the fall, young grass will have 2-3 months to become better established before temperatures drop too low and growth stops; the following spring, young grass plants will have another few months to develop deeper roots before the summer heat sets in.
• Overseeding lawns in the fall can also reduce competition from the weedy grasses of summer, like crabgrass.

 
Broadcast seeding vs. slit seeding: what’s better?
Slit seeding is the most effective method for overseeding, which is what we provide at Grand Landscapes. Slit seeding machines cut through the thatch layer (the layer of dead and living grass shoots, stems and roots that show up between the soil and the grass blades in your lawn), opening up a slit or small furrow in the soil. Concave disk blades follow in the slits to keep them open while the seed is dropped.
 
Slit seeding usually requires less seed than broadcast seeding because most of the seed gets right into the soil to germinate. When there’s more seed-to-soil contact, you get a higher germination rate and a stronger strand of new grass. We recommend making two passes with the slit seeder to create a diamond-shaped pattern for maximum coverage.
 
Broadcast seeding is still a good option, but it’s not quite as effective as slit seeding. You’ll have better results if you aerate your lawn before broadcast seeding (aerating can be beneficial prior to slit seeding as well), as the removal of soil plugs can make for better seed-to-soil contact. The challenge with broadcast seeding is that much of the seed doesn’t make it through the thatch layer so it doesn’t get into the soil to germinate, which is why you tend to need more grass seed in comparison to slit seeding. It’s also one of the reasons topdressing is often applied after broadcast seeding — because the topdressing material can helps protect the applied grass seed by shielding it from direct sunlight and retaining moisture for a higher rate of germination.
 
Do I need to do anything after my lawn is overseeded?
New grass seed can begin to emerge within two to three weeks after seeding, with proper moisture and temperatures. An overseeded lawn can be fully established in about eight weeks or so.
 
If there’s one thing you remember about caring for your lawn after it’s been overseeded, remember this: if the seed dries, it dies. Here’s what we recommend:

• Immediately after overseeding and up to 14 days, water lightly on a daily basis (ideally twice per day) to wash grass seeds into slits.
• From weeks 2-8, water less frequently, but allow for deeper soaking and penetration into the soil to encourage deeper root growth.
• After 8 weeks (once grass is established), water as you normally would.

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Getting a thicker, healthier lawn is easier than you’d think…when you’ve got the right ingredients. Send us an email or give us a call and we’d be happy to give you a quote or answer any questions you have about overseeding your lawn.