It only makes sense that if you have a brown patch of grass in your lawn, you just toss down a handful of seed and let it do its thing, right? Not necessarily. There are three schools of thought on planting cool season grass seed: anytime it is needed, in the spring or fall only, or only planting grass seed in the fall. Let’s get into the details of why planting grass seed in fall is the best option for a lush, beautiful lawn.
Competition and Weed Control
In the spring of the year, there are many more weeds and other varieties grasses that begin growing than sprout and grow in the fall of the year. If your new grass seed has less competition for water, soil space, sunlight and nutrients, it will have the best growth before going dormant for the cold winter months and will have an advantage over weed seed in your lawn when it begins growing in the spring again with a healthy energy reserve in the roots.
If you have more than one type of grass growing in your lawn, or are overseeding with a cool season grass, doesn’t it make sense to overseed while the warm season grass is beginning to die back? If you plant your cool season grass seed in the spring, it will only have a short period of time to become established before the warm season grass becomes active. Seeding in the fall helps remove competition from warm season grasses in the lawn.
Another way to help keep weeds down and provide a little more protection for your grass seedlings is by putting down a thin layer of clean straw. Why not hay? Straw is produced when grain is harvested, so all the seed goes into the grain truck, all the straw goes into the baler. Hay is typically cut while the crop is still growing, so it had a much higher seed content, leaving unwanted grain or weed seeds in the hay and, if spread on the ground, they’re added to the weed seed bank in your soil.
Why else is planting grass seed in fall a good idea? Giving new grass seed the duration of the fall, the warm periods during the winter and most of the spring to become established creates a hardier, thicker and more mature stand when going into the hot, dry summer. The drier fall weather gives the grass opportunity to put down deeper roots, beneficial in the summer. Fall planting also makes it have an easier and faster growth spurt early in the spring, which helps the grass to shade out and strangle any unwanted weeds.
You’ll want to plant your seed with 30 frost-free days; it would be better to plant 45 days before your region’s average first frost date. If you’re getting close to the 30 day window or have early frost, protect the new grass by setting up a smoker or water misters to keep the grass protected from the cold.
Lower Plant Stress
The other benefit of planting grass seed in the fall is that the grass plants experience less stress going into dormancy over the winter versus going into high heat over the summer. Plants use water to cool themselves, which is not a problem in the winter when it’s cool, but can kill plants over the summer if they can’t keep up with the cooling process. Since young plants are also going through early growth, planting in the sprint makes the plant deal with both the growth stress as well as the stress of pumping water to keep it cool.
Have you ever worked a garden in the spring of the year? The soil tends to be heavy or wet from frequent rains, cold or frozen as the soil is slowly warming up and can be difficult to prepare the seedbed for new seed. In the fall, there is typically less rainfall, the soil is cooling down instead of warming up and is often easier to work
Now that we have explored why planting grass seed in fall is a better idea, it’s time to put it into action! Keep in mind that this schedule works only for cool season grasses; warm season grasses typically need to be planted in late spring as they grow in different conditions. Enjoy a lush, beautiful lawn next spring by planting grass seed in the fall.