Many home lawns, especially those 10 years old or older, were established with common type turfgrasses which don't meet the needs of today's homeowner. These lawns tend to be more disease and insect prone, take more fertilizer and water, or they just have a plain old "worn out" look. Newer turfgrass varieties have been developed to withstand insects, disease, drought, shady conditions and heavy traffic better. The investment in overseeding pays off by reducing the amount of fertilizer, water and pesticides required. Most importantly, however, is that a renovated lawn looks better. It stays greener and looks healthier!
If a lawn has at least 50% or more healthy turf, it is usually worth saving by following good renovation practices: dethatching, core aeration and overseeding. However, if the lawn has less than 50% healthy turf, complete renovation and replanting may be the best alternative. This involves killing out the old turf, weeds, etc., and reseeding the entire lawn.

1. Apply a chemical such as Roundup^® to kill all vegetation
   • Apply at a recommended rate, when grass and weeds are actively growing.
   • Don't spray when windy, to avoid drift on other live plants.
   • walk from treated to untreated areas.
   • allow chemical to work for 7-10 days before starting follow up renovation steps.
2. Use a power dethatcher to remove excess thatch and debris from the treated lawn.
3. Aerate thoroughly, using a core type aerator.
4. Fertilize with a good starter fertilizer. Apply at the recommended rate.
5. Reseed using a renovator.

Reduce the recommended seeding rate by 1/2 and cover the area twice, in two directions, leaving a "cross hatch" seeded pattern.

(see illustration)

What type of grass seed is best?
Our climate allows for a range of grasses to be used, from Kentucky Bluegrass to Perennial rye grass, fine and tall fescues, zoysia and bermudagrass. Contact a local lawn & garden center for more advice on what type of seed is best suited for you.

When is the best time to overseed?
Late summer early fall is the best time to overseed lawns. Soil and atmospheric temperatures are most favorable for optimum seed germination and growth. With adequate moisture, fertilizer and sunlight, the new seedlings will be well established before cooler fall weather sets in. Also, weed competition is less of a factor at this time, giving the grass seedlings a better environment to grow and develop.
Spring overseeding can also be done, but there is more of a chance of weather related problems (heavy spring rains, extreme high temperatures) and weed competition is more prevalent in the spring. Also, spring seeding may interfere with application of pre-emergent weed killers; concurrent application of seed and herbicides is generally not recommended because the herbicides may cause poor seedling establishment. It is best to delay herbicide treatment 4-6 weeks after new grass seed germinates.
Midsummer overseeding can be done, but it is not recommended. Increased chances of disease, heat and drought stress, and weed competition tend to make seedling establishment more difficult. Proper weed control and adequate irrigation are musts if overseeding is attempted in midsummer.

What about care after overseeding?
Proper watering is critical to successful overseeding. The following is a recommended watering program:
Immediately after overseeding: Water heavily to wash grass into slits.
Until grass seeds germinate: Water lightly on a daily basis, soaking first 1" of soil.
After grass becomes established: Water at recommended level for the type of grass planted.

Methods of overseeding an existing lawn
Overseeding with a broadcast spreader
Aerate several times before broadcasting seed. Use a core type aerator, such as a Ryan brand, that removes soil plugs for better seed-soil contact. After overseeding, give the area a heavy watering right away to wash the seeds into the aeration holes.

Slit seeding with a mechanical seeder
This is the best method of overseeding established turf. Slit seeders usually have verticutting blades that cut through the thatch layer and open up a slit or miniature furrow ¼" in the soil. Slit seeding generally takes less seed than broadcast seeding, because most of the seed gets into the soil so it can germinate. More seed-soil contact means a higher germination rate and a better stand of new grass. It is best to seed in the same "cross hatch" pattern as described and illustrated above.

We have illustrated pamphlets on overseeding and aerating. Please feel free to stop by and pick some up.

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