I struggle every year with the question, “Is it too late to plant grass seed?” Most of the time it is a trick question because I don’t always know what to expect with the weather. The rule in Tennessee is ‘If you don’t like the weather, just wait 20 minutes!’
Grass seed is both easy and difficult to figure out. Also, knowing what grass you are planting can be an issue. It you want to plant a warm season grass, i.e. Bermuda, Zoysia, St. Augustine etc. then you have to have hot temperatures in order for it to grow. If you want to plant cool season grasses, i.e. Fescue, Rye, Bluegrass, etc. then you will want to wait for cooler temperatures to plant them. Most people in my zone like to plant Fescue for year round green. The ‘textbook’ time to plant Fescue is September 15th.
Fescue seed in average 70 degree temperatures, takes two weeks to germinate. “What does germination mean?” Good question. Germination is the process of the shell of the seed cracking open and the root goes down and stem goes up. Warm, moist conditions help accelerate this process.
Back to our original question. The later in the season you get, the colder the ground temperature becomes. When you are getting freezing nighttime temperatures, it will hinder the germination rate. Will it still germinate, yes. Waiting until November to spread grass seed is a gamble that we will still be getting warm temperatures to help germinate the seed. It should work, but it also might not.
A side note…The old wives tale of throwing out grass seed in the snow is actually an accurate statement. The snow provides ‘thermal warmth’ and will give the seed plenty of water to germinate. Try it and see.