The act of spreading a layer of grass seeds across your existing yard is called overseeding. It’s a good thing. In fact, overseeding is a landscaping little secret for growing a green and lush lawn.
Even in a healthy lawn, grass will die every season. This is particularly true in colder climates (we’re looking at you, Montana). Overseeding your lawn will help replace dead grass and, at the same time, thicken up your lawn which is good for aesthetics and weed resistance.
Overseeding typically applies only to cold season grass lawns. It should be a regular part of maintenance for a cold season grass lawn. For warm season grass the term overseeding often means spreading Ryegrass over a Bermuda grass lawn in the fall to provide some ‘green up’ over the colder winter months when Bermuda grass is yellow and dormant. Although in some cases traditional overseeding practice can be used on certain warm season lawns. Bermuda lawns can be overseeded with Bermuda grass in the spring if there is thin or patchy growth, or reviving a damaged lawn.
To learn more about grass types and recommended growing regions visit our Comparing cold and Warm Season Grasses article here.
Depending on the region you live in, overseeding times and strategies will differ.
COLD SEASON GRASS (Northern US)
If you live in the northern US, it’s recommended that you overseed your lawn in the fall, so that new grass can establish itself in the milder fall weather. So, plan to overseed at least 45 days before the first frost. For most regions the ideal time is September or October when temps are in the low 70’s during the day. Otherwise, you can overseed in the springtime as long as the young grass gets established before the summer heat sets in.
WARM SEASON GRASS (Southern US)
The best time to overseed your lawn in the Southern states is late spring or early summer, since warm season grass types need fairly warm soil in order to germinate and grow. Aim to overseed on a beautiful 65 F° day. Fun Fact: In the south, it’s popular to overseed Bermuda grass lawns in the fall with perennial ryegrass to “green up” a lawn during the inevitable cold season dormancy.
Before you overseed, determine your existing grass type. It’s key!
PRO TIP: Watering is vital to initiate seed germination and to get young grass to grow. Make sure your lawn doesn’t dry out but don’t overwater it either. It all depends on your climate. Many areas in NE (i.e. Boston) and NW (i.e. Portland) may not have to water all all, while drier areas like the Texas panhandle may need to water every day until seeds germinate.
Cold Season Grasses*
Warm Season Grasses*
*Be sure to follow seed manufacturer’s specific application recommendations.