What type and when to fertilize after overseeding #851165

Asked September 25, 2023, 12:59 PM EDT

Good afternoon. I just made two productive dethatching passes and wanting to overseed. I have several questions. 1. Should I also aerate or scarify? 2. What type of fertilizer should I use with the seed. I’m using a Kentucky blue, tall fescue and rye. 3. Do I mix the fertilizer with the seed? 4. Straw, peat or nothing to cover? As always… thank you. Ron

Cuyahoga County Ohio

Expert Response

i see your doing your homework. I recently finished seeding bare spots and i did it in a lite rainfall. I noticed germination in 5 days. The best time to seed is in the fall. warm soil and warm temperatures. When it comes to aerating i listened to the professors at OSU who said if your going to aerate its best to do it every year. I tend not to aerate or scarify the lawn. Thatch is not a problem for me as i use an organic fertilizer and have very little thatch. I also use milorganite in the fall. Best time to fertilize is in the fall and stop in October. Some thatch should not be a problem.
When i seed i use a green mulch that when wet it turns dark green and when the soil begins to dry it turns lite green. This tells me to mist the seed bed. So many people tend to over water their seed bed.
I like your choice of seed, I use the tall fescue  as it blends in with other blues.
Fertilizer of a 10-10-10 is a good choice. Seed starter fertilizer is good to buy from your local store . Many fertilizers are a 24-0-10 or something like that , but i like the 10-10-10 or something like that. I did fertilize in September and will fertilize again in October. That way i will not have to fertilize in the spring. I do not have crabgrass so that helps as many crabgrass preventers in the spring have the fertilizer in it. I tend to half my rate of fertilizer in the spring and fertilize in may. My neighbors are always complaining that i never mow the yard in the spring while they are doing 2 a week mowings. When it comes to weeds, i wait until the soil warms and do spot spraying. Then at the end of june or early July i use a treatment for insects that lasts awhile. I use meret in my treatment. It takes care of many insects such as grubs etc. I do realize new treatments are coming out every year so pay attention to what is available. Once you get on this program you may find your lawn does well. We had a wet mid summer and many neighbors did not put down insect control and now the grubs have taken over. Those who have sprinkler systems may not see damage as the grass sends out roots as the grubs eat their share.
I realize i addressed more than what you asked. I should remind you to do a soil sample to see what your soil needs. Contact your local extension agency for help.
Hopefully this answers your questions. If you have more concerns let us know. Thanks for the question. 
winfield sturgeon-mgv Replied September 25, 2023, 3:06 PM EDT
Thank you for a comprehensive summation. It gives me a lot to chew on and to consider. I recently retired and want to take over my fertilization program from a reliable and convenient company. 

On Sep 25, 2023, at 3:06 PM, Ask Extension <<personal data hidden>> wrote:

The Question Asker Replied November 02, 2023, 1:28 PM EDT
If your weather was as cold as our weather in NW Ohio, i recommend you do no fertilizer in November. In the spring if your seed has not germinated, it will take warm weather for ground to warm up and the seed to germinate. Applying material to stop crabgrass from germinating will also stop your seed from germinating. Something to consider. Then, apply fertilizer designed for young grass seed. Once it germinates wait 2-3 weeks for it to grow well and then crabgrass application, even though it may be to late for the summer. You will have to apply spot crabgrass when it germinates. I have not used anything for crabgrass in 50 years. When i do see some germinating, i pull it out, but i have very little.
This past spring i did apply some grass seed in the spring. We had such a cold spring the seed never germinated. That is why fall seeding in august through sept is the best.
winfield sturgeon-mgv Replied November 03, 2023, 8:55 AM EDT

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