Core Aerator vs Verticutter

What’s the difference between core aeration and verticutting?  Which one should I use on my lawn? We get these same questions from customers every year. During fall overseeding season, there are many different options as to how to prepare your lawn for renovation. Ultimately, the homeowner needs to make the decision based on the condition of their lawn. Understanding the benefits of each will help you make the right choice for your overseeding project.

Verticutter for Planting Grass Seed

Verticutting machines have many “vertical” blades that cut multiple slits or grooves across their path. The more grooves you make in the soil, the better seed-to-soil contact. The better seed-to-soil contact, the better seed germination you will get when overseeding. A verticutter will be the best tool to use for overseeding when attempting to establish large areas

In addition, verticutting helps reduce thatch buildup, which can inhibit water and nutrient movement. It also encourages new growth by cutting into the soil and promoting lateral spreading of grass runners (stolons). However, it can be more disruptive to the lawn’s appearance than core aeration due to the soil and thatch being pulled up.

What is a “slit seeder”?

Some models of verticutting machines have an attached seeding box. These types of verticutters are known as slit seeders. The attached seed box is meant to distribute grass seeds as you slice the soil. Although designed with good intentions, NEVER use the seed box! The seed boxes on these machines may contain contaminated seeds from previous renters. In addition, the seed boxes will not accurately dispense grass seed at preferred rates. Apply your grass seed using a broadcast spreader for accuracy and efficiency.

Uncle’s Tip: Use a verticutter for total lawn restorations when the majority of your lawn is a weed patch, dead grass or bare ground. Apply Grass Pad seed first then verticutting the lawn in two directions (recommended for best results) will drill the seed into the grooves made by the verticutter. This practice mimics how a farmer drills his crops into the field. Drilling grass seed into the soil utilizing a verticutter can help reduce seed washout due to unexpected heavy rains. 

Core aeration helps the soil!

Core aerators are heavy machines that pull cores or plugs from the soil. The benefits of core aeration are to reduce the bulk density of the soil and improve gas exchange and water infiltration, which in turn benefits nutrient uptake and strengthens the root system of your grass. Homeowners with thick turf, poor drainage, or heavy soil compaction will benefit from hollow tine core aeration. Core aerators are not the best tool for overseeding, but they are the best method to improve soil conditions to help the grass grow.

Uncle’s Tip: If your lawn is thick, vigorous and healthy you may not need core aeration. If you should choose to core aerate, run the machine over the lawn multiple directions. Recommended aerification intensity is  20-30 cores per square foot for cool season grasses (40-60 for warm season zoysia grass). After aerifying, overseed and fertilize the entire area. Expect to see more weed germination after aeration from the exposed weed seeds.

Hollow Tine Plug Core


Areas with hard compacted soil and poor drainage will benefit from Primera Sports Field Conditioner immediately after core aeration. Primera Sports Field Conditioner, calcined clay particles, will fill the aeration holes and soil substructure to prevent the cavities from collapsing and increasing the soil porosity.  Calcine clay adds permanent air-holding pore space, decelerating natural compaction and improving water infiltration and gas exchanges. Each particle acts like a sponge that holds beneficial microbes, air, water, and nutrient near the root zone.

Which to Use: Core Aerator or Verticutter?

The choice between the two depends on the specific needs of your lawn and the issues you’re aiming to address. When soil density needs to be improved, use a hollow core aerator; when you need to get maximum seed germination when large overseeding areas, use a verticutter. When you have a few bare spots, use a garden rake. It does not have to be complicated. In any case, every fall season, overseed your lawn with Grass Pad quality seed and fertilize with Loveland RenovatorGolf Course Starter, or Loveland Supreme.

Uncle’s Tip #1: Moist soil is best when verticutting slices in the soil or pulling up aeration cores. Two to three days in advance, water your lawn thoroughly to moisten the soil and reduce dust.

Uncle’s Tip #2: Speed up grass seed germination by keeping the seed moist. Covering grass seed in bare and open areas with PrimeraFC or sphagnum peat moss will help hold moisture over the seed. The seed on the ground won’t germinate if you can see it.

More Related Articles on Verticutting or Core Aeration

Steps to Fall Overseeding

How to Choose the Right Grass Seed

Total Lawn Restoration

Hard Clay Soil? Tips to Reducing Soil Compaction


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