Though a lot of people reseed their lawns in the spring, there are periods during the fall that are actually better for most grasses than spring seeding. Exactly when this seeding window is depends on both where you live and the type of grass that you’re putting seed down for. This may lead some people to believe that any time late in the year is ideal for reseeding a lawn prior to spring; unfortunately, that isn’t actually the case.
If you reseed your lawn at the wrong time of the year, there’s a good chance that you won’t get the results that you expect. If your grass is thinning or has otherwise been damaged, this can result in bald patches come spring that require a lot of work to correct. To avoid this, let’s look at when you should (and shouldn’t) reseed your lawn and why.
Depending on the seed that you’re using, the window for reseeding late in the year typically comes in the late summer to early fall. Most of the time, your existing grass is slowing down its growth in preparation for the winter. The soil is still warm, however, and winter frosts are still several weeks away. There’s also a decent chance that you’re still getting frequent enough rains to keep the soil moist and the leaves on your trees haven’t yet started falling in earnest.
So what is it about this time period that’s so perfect for reseeding a lawn? Because the soil is still warm and reasonably damp, your seeds will start germinating quickly. The surrounding grass isn’t growing as aggressively, though, so the germinating seeds will experience less competition for moisture and nutrients as they establish their roots. By the time the leaves fall, your new grass will already be getting established and will then receive extra protection throughout the winter and a burst of nutrients as those leaves decompose. It’s just about the best start that young grass could ask for.
Reseeding in the Winter
Unfortunately, the same situation doesn’t exist if you reseed in the winter. Even if you’ve had a fairly mild winter early on, colder winter nights will result in soil that is much cooler overall. Rain may also be less common depending on where you live, meaning you’ll have to supply more of your own moisture to the growing grass. Moist soil cools quicker, however, so the issue with the cold nights will become even more significant; it also creates an increased likelihood of frost, which can damage or kill fragile young grass.
Of course, these problems assume that your grass can germinate and start establishing itself at all. Average temperatures and the cycling through colder nights may cause the grass seed to not germinate, and the increased scarcity of food will make the seeds you spread much more appealing to birds and insects if you don’t keep the grass seed covered. The fallen leaves that provide protection to your seeds during a fall planting can actually create a barrier that keeps them out of the soil come winter as well. If winter has come and you need to reseed your lawn, you’re much better off waiting until early to mid-spring and reseeding then.
If your lawn has significant issues, there are still options available to you. You may be able to replace patches with sod, or look at alternative ground coverings that thrive in colder weather. A landscaping pro in your area should be able to discuss your various options with you and help you develop a plan for how to get the lawn you desire.