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.

Dormant Seeding Dos and Don’ts

lawn that needs dormant seeding

If you live in the south, dormant seeding is not something you can do to help your existing lawn. Seeding for warm season grasses is generally completed in the early summer. Although seed is available for many warm season grasses, getting it to germinate can be a real challenge. Most repair work is done using sprigs or by resodding bare areas. If you live farther north, where cool season grasses like bluegrass, perennial ryegrass and fescue make up the majority of lawns, you can still lay dormant seeds at this time of year. The one consideration is that you have to live in an area where the winter is normally cold and damp. It is important that the new dormant seeds do not have the chance to germinate and then be exposed to freezing temperatures that can damage the seedlings.

You have to wait until the chance for warm weather to return is minimal. In northern Illinois, late October is about the earliest you want to dormant seed a lawn. Personally, I have dormant seeded a lawn in the Chicago area as late as early December and had fairly good results. Dormant grass seeding is pretty straight forward. You follow the same procedures as you would for seeding in the late summer or early fall. Dormant seeding works best in areas where the grass has thinned out due to adverse weather conditions, excessive traffic or from disease or insect damage.

Thick, dense lawns will have to be core aerated first to make sure that there is a place for good soil to seed contact. Thin lawns also require some prep work prior to seeding. If the area is not too large, using a good hand raking to loosen the soil at the surface is the best approach. If the area is larger, it is best to core aerate it in several directions to provide areas for the seed to germinate. Most rental companies, home improvement centers and hardware stores have core aeration machines for rent. Lawn care companies, like Spring-Green, offer core aeration as an optional service. This may be the best way to go as a core aerator will not fit in most cars or even SUVs.

Once the site preparation is completed, spread the dormant seed across the areas that need to be seeded. For a bluegrass/ryegrass blend, spread about 4 to 5 pounds of seed per 1,000 sq. ft. For Turf Type Tall Fescue, you will want to use about 6 pounds of seed per 1,000 sq. ft. One thing to keep in mind is the number of seeds per pound.

  • Bluegrass: 1,500,000 seeds per pound
  • Ryegrass and Turf Type Tall Fescue: 250,000 to 400,000 seeds per pound

If you purchase a 10-pound bag of seed that is 50% bluegrass and 50% ryegrass, you are getting about 7,500,000 bluegrass seeds and about 1,250,000 ryegrass seeds. If you want more bluegrass than ryegrass, this blend would work fine.

Once you have finished dormant grass seeding, you will have to wait until spring to see the results. The dormant seed will not germinate until soil temperatures reach about 55 degrees. You do not want to apply any crabgrass preventer to the areas in the spring since that material will also prevent your new seed from germinating. If you do get crabgrass, you may have to hand-pull it next summer. The same is true with broadleaf weed control. Hopefully, your lawn will fill in enough that these weeds will not be a problem.

Along with core aeration services, Spring-Green can also treat your lawn for crabgrass and broadleaf weed control. Click here to contact your neighborhood Spring-Green Lawn Care professional.

Dormant Seeding in the Winter for Home Lawns

What is dormant seeding?

This is a process where seed is sown during the winter months of November to March. The seed will remain in a dormant state until the ground warms up and soil moisture is adequate to promote germination. The key to dormant seeding is good seed-soil contact. A good way to create places for the seed to germinate is to core aerate the lawn prior to seeding. You can rent a core aeration machine if you have a vehicle large enough to transport it and the muscle strength to handle it. Most people hire a lawn service to do the work for them. The lawn has to be moist for good penetration of the coring tines and, of course, the ground cannot be frozen.

The seed is generally spread with a rotary-type spreader that will evenly distribute the seed across the lawn. Depending upon the seed you are using spread about three to six pounds of seed per one thousand square feet. For example, bluegrass seed contains about 1.5 million seeds per pound whereas Turf Type Tall Fescue contains about 250,000 seeds per pound. A little bit of bluegrass goes a long way.

It is very important that you do not apply pre-emergent crabgrass preventer during the spring. These products create a barrier that kills newly germinating crabgrass seeds. It will also kill the new grass seed that was put down. You may have to live with some crabgrass for a year, but if you water and mow high you can keep its population in check.