I've been in my home for about 12 years and have aerated once.

If you mulch mow your lawn and mulch the leaves in the fall, you'll increase the organic content and attract worms. The worms will then take care of doing the aerating for you.

Thank you bpgreen also what is the best way to overseed I was going to rent a pull behind slice aerator that is a drop spreader I would like to do it this weekend due to potential frost in six weeks

I've never used a slit/slice seeder, but from what others have said, it might be best to use it just to rough up the soil. If you core aerate and really go over it a lot, you don't need to use the slit seeder.

I've read comments by several people that if you use the slice seeder, you should go over the lawn in a couple of different directions, with the second one at a 45 degree angle to the first (say N-S, then NE-SW) rather than at a 90 degree angle. The reason for this is that if you just go in one direction, you get rows. If you go at 90 degrees, you get a checkerboard effect.

I've also read from many people that they prefer to use it just to rough up the soil because you can get uneven seeding rates from the spreader on the slice seeder.

Thank you

In a perfect world you should aerate twice a year (spring and fall). It usually takes about 2-3 years to really notice the improvement. Not all soil needs to be aerated, but if you have a lot of clay, it is beneficial. A slit seeder works very well for overseeding, but since I own an aerator I just aerate well and then use a drop spreader to apply the seed.

Thanks Guys I have another question has there been good luck with laying the seed down at or just before the first frost and letting the seed set over the winter? I forget what this called

"I have another question has there been good luck with laying the seed down at or just before the first frost and letting the seed set over the winter? I forget what this called"

That's called dormant seeding. I've had good luck with that, but if you have enough time between when the heat breaks and when you have your first frost and you can keep the seed moist, fall planting will be better.

It may have been cool enough this past weekend for me to seed, but it was still getting pretty hot, so this coming weekend would be better. Average first frost here is October 10. That would give me three weeks between seeding and first frost, which isn't nearly enough. A "normal" spring seeding wouldn't give the grass enough time before the summer heat hits. Dormant seeding gives a bit of a jump start.

So for me, dormant seeding is my best option. For most people with cool season grass, fall seeding is probably best and dormant seeding is probably second best. Spring seeding is usually not as successful since the new grass is too fragile to get through the summer. The exception is places where the summer doesn't get too hot, in which case, a spring seeding has a good chance of success.

I aerated once because I got talked into and didn't know any better.

Thanks BP
If I dormant seed when should I do it here in NewHampshire?

Dormant seeding should be done after it is too cold for the grass to germinate.

You're probably hoping that I'll tell you a date to use, but there are too many variables.

Some people try to do it just before the first snow of the winter. Around here, that can happen while the soil is still warm, so it doesn't always work. If you don't get it down before the ground is snow covered, you'll need to wait for a time when the snow has melted.