Whether you have an established lawn or are planning on one, you may be wondering if you can plant grass seeds in cold weather, as you certainly would not want to end up with a bare lawn if the grass seeds do not survive the winter.
And so we created a little guide to all the things you need to know about grass seeds and the cold, so let’s get into it!
Can Grass Seeds Withstand the Cold?
The grass seed itself is rather tough against extreme temperature; they won’t perish even in consistent freezing temperature.
However, they can suffer damage due to temperature inconsistency.
Inconsistent frost only causes soil to go through cycles of freezing and thawing and causes moisture to be trapped around the seeds, leading to the rotting of the grass seed and eventual death of the seed.
Mechanism of Survival
Grass seeds can tolerate frost because of dormancy.
As long as the seeds haven’t undergone germination at the time of frost, the seeds go into a dormant or hibernation survival phase to deal with the unfavorable conditions.
While the seeds are dormant, they can go through priming, activating enzymes, and breaking down the endosperm.
Then, when winter begins to break down and conditions are optimal again for the temperature, germination is activated, the roots appear, and now the grass plant is coming to a nice lush lawn.
Utilizing Harsh Conditions
In fact, the dormancy characteristic is applied by grass growers as a way to get a head start when springourne approaches in what is referred to as “Dormant Seeding.”
Instead of waiting for the soil to thaw completely, they sow their grass seeds in the depths of winter, putting the seeds into a dormant state.
The good news is that once the conditions are conducive, grass seeds will resume flowering again.
Dormant Seeding
Various growers are implementing the dormant seeding method while installing their turf.
Indeed dormant seeding could cause seeds to produce grass earlier in the spring with a potential advantage of up to 15 days relative to spring seeding.
Dormant seeding also provides another option when you miss your ideal sowing timeframe, and you surely don’t want to wait another growing season.
As winter soil is dry, this helps provide good soil-to-seed contact and a lower risk of required weed control and vigilance for diseases.
The downside of dormant seeding is the risk of birds and rodents consuming your seeds before they have an opportunity to grow.
Can Grass Seedlings Withstand the Cold?
Although grass seeds can survive freezing conditions, the same cannot be said for the baby grass seedlings.
The problem here is the baby grass seedlings have short weak roots and very little leaf surface area to leverage as a resource for survival.
Young roots, even grass seedlings, lack the amounts of energy necessary to survive if frozen, and once the roots of the young plant freeze, the entire plant is deprived of water and nutrients.
In addition, having very little leaf surface area means the grass seedling will not be able to obtain enough food and energy through photosynthesis either.
Without water and or food, the seedling will die over the winter.
It typically takes at least six weeks for a grass seedling to develop a root system that is strong enough to guarantee survival.
Best Practice: The best practice is to ensure that sowing is done at the correct time so that the grass seed has enough time to prepare for the long brisk winter ahead.
Protecting Grass from Frost Damage
So, what if you already began to plant your seeds less than six weeks before that first frost?
What if your seeds have already started to germinate when there is a frost?
Don’t worry; it can still be salvaged.
Fortunately, there are some things you can do to cover your seedlings from frost.
Watering the Grass
In the beginning, grass must remain moist.
Watering serves to retain heat, which will keep soil from freezing.
So, to protect your seedlings from freezing temps, water your soil a few times, intermittently, during the night with warm, tap water.
Covering the Lawn/Landscape
Secondly, you will need to find a cover. Tarp, plastic, cloth, and lumber are all good options.
You will want to cover the seedlings up in the evening (to trap heat) and expose the seedlings to fresh air and warm sunlight during the day.
Works Well: Covering the seedlings overnight serves the same purpose as watering the soil: trapping heat. The cover helps hold warm air close to the soil to prevent freezing.
Avoiding Pressure
Lastly, do not press on or walk on frozen grass.
When human feet, livestock, or farm vehicles go over frozen grass, it gets “broken.”
Sometimes, this damage is irreversible, and once again, it is best to avoid any pressure on unthawed grass.
Types of Grass
It’s also good to recognize the various types of grass before you embark on your grass growing journey.
The most familiar classification of grass is simply warm-season and cool-season grass.
We can take a closer look.
- Warm-season grasses: Prefer daytime air temperatures of 80 – 95 F (27-35 C) and soil temperatures of 70 F (21 C).
- Cool-season grasses: Prefer daytime air temperatures of 60 – 75 F (15-24 C) and soil temperatures of 50 – 65 F (10 – 18 C).
Bottom Line
As indicated, grass seeds tolerate frigid winter months by becoming dormant.
However, they must have a consistent temperature, as inconsistent temperature will kill the seed by freezing and defrosting multiple times.
So, if you store grass seeds, you need to be aware of this.
The other point I mentioned about dormancy led to the idea of dormant seeding, a favored method in grass growing practices.
They oftentimes begin seeding the lawn in late fall to allow the seeds to remain dormant and then germinate in the following spring.
What is at risk from the cold is the grass seedling, which the cold can kill.
To avoid having seedlings in the winter, plant at least 6 weeks ahead of the first frost date.
You can still protect your grass in the winter even so, utilizing warm tap water to water the soil if it frosts, covering the grass for the night, and trying to avoid dead contact for the grass if it frosts.