You may think that by November, there are no more lawn care chores to be done. Yet, there remains one activity that can still be done to help repair or thicken the lawn for next year. That task is known as dormant seeding.
The idea is that the seed will remain "dormant" due to the cold soil conditions, but begin to germinate as soon as the soils start to warm in the spring. This avoids having to prepare the soil when it is still wet and cold in the spring and can result in a head start of several weeks in getting the lawn established.
This method generally works best when the newly seeded areas are covered with several inches of snow soon after seeding that remains in place over the entire winter period. "Open" winters with extended warm periods followed by extremely cold periods can negatively affect spring germination of dormant seeded lawns.
Dormant seeding works best when you want to reseed bare soil areas or help thicken up thin lawns. It is not as effective where lawns are thick and dense because good seed-to-soil contact is necessary for the grass seeds to germinate and grow next spring.
When to dormant seed
The time to dormant seed is important. If done too early, some seed will germinate late in the season and those immature seedlings often won’t survive the winter. Put down your seed while the ground is not frozen, but is still cold enough so germination of the grass seed will not occur until next spring. Usually this is sometime from late October to mid-November depending on your location within the state.
Other than the time of year for dormant seeding, the actual process of preparing the area to be seeded is virtually identical to establishing grass from seed at other times of the year.
Choose well-adapted seed
When choosing the seed to use, be sure to select seed mixes that are well adapted to both your site conditions and the amount of maintenance you expect to provide during the growing season. For average lawn conditions, mixes containing some Kentucky bluegrass, fine fescue and small amounts of perennial ryegrass can be sown at about three to four pounds per 1,000 square feet. Virtually any grass seed mixture can be utilized for a dormant seeding.
Establish good seed-to-soil contact
Mow the existing lawn slightly lower than normal, down to about 2 inches. This will allow seed applied over the top to reach the soil. Loosen the soil surface so the seed can easily be incorporated into the surface quarter-inch or so of loose soil.
- Small areas of bare soil or even a thin turfgrass stand can easily be prepared using a hand rake.
- Larger areas of sparse turfgrass can be prepared by 'lightly' going over the surface with a power rake or vertical mower available from most rental agencies.
- Set the blades just deep enough to penetrate into the top ¼ inch or so of soil.
- This will also help remove small thatch layers that may be present, as well as any dead grass plant parts laying on the surface of the soil.
- Rake up the grass plant debris that was brought to the surface from this process so that it will not interfere with sowing the grass seed. This debris can easily be composted or used as a mulch in another area of the landscape.
Once the soil is loosened, spread grass seed at the recommended rate and lightly incorporate into the existing soil by the use of a hand rake.
Another machine known as a slit seeder could also be used. This machine creates a shallow slit in the soil into which the seed is dropped, lightly covered and packed down. There are some rental businesses that have such units available. More commonly this is a practice done by a lawn care professional.
Water thoroughly, but not too much
Water the area thoroughly and leave it until next spring. Apply from 0.05 to 0.10 inch of water. At this time of year, cool temperatures and short days will help keep the areas moist far longer than in summer. While just barely damp soil is okay, it is important that the area does not become soggy and saturated with water.
If the weather does turn a little warmer and drier and the area starts to dry out, it may be necessary to lightly water the area just to keep it damp and prevent it from becoming too dry. However, in most cases it will be unnecessary to do this.
What to expect for next spring
The success your dormant seeding will depend on the winter conditions. The seed is best protected when we receive snowfall that will cover and protect those areas. You should be able to see germinated seedlings by late April or early May in most years. An assessment can be made at this time if additional overseeding needs to be done.
If the newly seeded areas appear to be a little thin, you shouldn't necessarily feel your fall efforts were a failure, as it is quite common to have to do a little additional reseeding in the spring. However, do allow enough time for the seeds to come up. Don't be too hasty to get in and start tearing things up; you just may be destroying all of the good work done the previous fall.
If you are certain the dormant seeding did not succeed, the area can always be overseeded the following spring. The light disturbance of the dormant seeded area during an overseeding process should not be a significant problem for the seedlings that have germinated. However, of the young seedlings that are germinating, it is important to not tear them out or destroy them by excessive traffic on the dormant seeded area. Consider fertilizing these areas in May to encourage establishment.
Reviewed in 2018