I had our lawn aerated on Sept. 9 and spread Scott's Sun and Shade 901717 Grass Seed with my Speedy Green spreader. The grass seed was about 2 years old, stored in my shed. Today is a week and a half later and with daily watering, I have not seen any sign of new growth at all. I'm thinking the seed was too old and I would like to buy some new seed, but I need to know if it's too late to do so if I want any growth before the cold weather comes. What do you think?
Actually, the fall season is a wonderful time to overseed your lawn with a cool season grass. It gives the grass time to develop roots before the winter sets in. You need to have patience, though. Seed germination happens when the seed absorbs sufficient moisture to start sprouting. This is regulated by soil temperature according to the variety of grass. The hull, or hard outer casing, may delay this process until conditions are favorable. To test the “old” seed you used, if you have any left over, place about 10 seeds between two moist paper towels, the put into a plastic bag, but do not seal tight. Set this on top of your refrigerator where it is warm, keep moist, and within a week or so you should be able to see if any sprout. If only 1 or 2 sprout, it means that only 10% or 20% of your seed was still viable and it would probably be best to purchase new seed.
When overseeding, you need to make sure that the seeds reach the soil, so aerating your lawn area was perfect. Keep the soil moist (but not overly wet) by lightly sprinkling two to three times a day. Be careful not to soak the soil repeatedly or you could encourage root rot diseases. As the grass grows, allow the soil to dry slightly before watering again. You may want to cover the seed with a blanket of straw to keep the birds from stealing the seed.
A soil test would be a good thing to have. It would tell you what nutrients you need to add to bring the soil up to optimum grade to grow grass. (http://msusoiltest.com/get-your-soil-test/)
This is a site with some good information: http://www.lawn-care-academy.com/overseeding-lawns.html
Hope this was helpful. Feel free to contact us again if you have further questions.