Should I aerate and overseed or slice seed?

Which Is Better Aeration & Seeding or Slice Seeding?

A toro slice seeder
Which machine will better serve your needs.


When fall comes, and with it cool temps and moist ground, seeding becomes the single best thing you can do. It is often disputed which method of application for seed will produce more germination, aeration and over seeding or slit seeding. It seems like in the lawn care market it’s a pretty even split in opinion among providers. The answer may be a little more blatant than you think.

For optimal seeding results slice seeding is the better method.


Here is why, slice seeders are made for seeding and aerators aren’t, it is that simple. Slice seeders are adjusted to cut at the proper depth for the seed you are using, usually a quarter of an inch. The slices into the soil are calibrated to give an even seed bed. The other nice part of slice seeding is that the machine will lay down seed, from a built-in hopper, in the path of the teeth, ensuring that the seed is worked into the soil and not just left on the surface to rot. Calibrating the rate of seed is also quite easy, just look for a calibration chart under the cover of the hopper (in most instances). Match the dial on the front of the machine to the recommended rate of application.

A slit seeders calibration
The adjustment for seed can be found under the top of the hopper.

I don’t want you to think aerators are terrible machines or a scam it’s just that an aerator does not offer a proper seed bed, which can produce poor results. Core aeration plants seed too deep. The seed cannot establish itself though two to three inches of earth. The only seed that may do well is what ends up lying with broken down soil cores left after aeration. Still this small amount of germination will not have an impact because the tines on an aerator aren’t close enough to really fill in thin spots.

Don’t just throw away your aerator.

An aerator
Aeration is a great choice, just not for seeding.

It has to be noted that aeration alone is a great service and should be done annually or more depending on the amount of foot traffic. Relieving soil compaction will produce visible results in the following months, increasing the amount of water and nutrient uptake is paramount to a perfect lawn.  So if you have run around selling aeration, do not feel like you’ve been doing it all wrong, you haven’t. Aeration is an important service for your customers.  But, if you need to fill in bare spots, thicken up a thin lawn, or mix in a new turf type than slit seeding needs to be the service you are selling  your customers. Your customers will be happier with the results of the service and you will be proud of the results of your labor.

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