Dormant Seeding: Is There Still Time To Seed Cool-Season Turfgrasses?

soil plugs from core aeration

Even though much of the northern US has been enjoying a warmer than normal fall, it will soon be turning cooler in the next couple of weeks. If you are still planning to seed, you may want to consider dormant seeding at this time of year.

When Can I Begin Dormant Seeding?

Dormant seeding works best when the soil temperature drops below 50°F or when the ground is frozen, providing that snow is not covering the lawn. If soil temperatures are too high, it can result in the seed germinating too soon. This causes the germinated seed to succumb to frost or freezing temperatures in the coming weeks.

The easiest way to check the temperature of the soil is to use a digital meat thermometer. Stick it in the ground to a depth of about two inches to take the reading. (Be sure to wipe it off before using it in your Thanksgiving turkey.)

What Is the Process for Dormant Seeding?

Another important aspect of dormant seeding (really, overseeding in general) is having good “seed to soil” contact. If you sow seed across an established area without much exposed soil, only a small portion will germinate. The easiest way to achieve good seed to soil contact on an existing lawn is to core aerate it first. Be sure to do so before the ground freezes. The more you aerate, the more places for the seed to germinate, both from within the core holes and from the plugs that remain on the lawn.

What Kind of Seed Is Best for Dormant Seeding?

Purchase good seed that is free from weed seeds. Cheap seed will provide poor results. Here is a table that will help you decide how much seed you will need to buy based on the size of your lawn:

Seed Type Table

Can I Fertilize the Grass Seed Before Dormancy?

As long as the ground is not frozen, fertilizer can be applied, even in states that have a ban on the use of fertilizers that contain phosphorus. A balanced fertilizer with phosphorus can be applied on newly seeded areas. Phosphorus aids in the development of roots. Therefore, it is a beneficial nutrient to apply after seeding.

What Do I Do in the Spring?

Once you have spread your seed there is not much else to do until the following spring. Here are a couple of other considerations to keep in mind for the following spring:

• Delay applying crabgrass preventer until the middle of May or as late as possible. The product that inhibits the growth of crabgrass will also inhibit the new grass seed from germinating.
• Delay applying a broadleaf weed control application until the new seed has started to germinate and has been mowed at least two times.
• Applying an additional balanced fertilizer application will help the new seed germinate faster.
• Mow your lawn during the spring. It is important that as much sun as possible reach the seed you planted the previous fall. The soil has to reach above 50 degrees for the seed to germinate.

Dormant seeding will work, but you have to be patient. You will see the results by the following summer. And if you want the results without the work, we offer all of the services to get your lawn in shape—contact the Spring-Green nearest you for a free estimate.