What is a Slit Seeder?

Slit seeding fescue lawn turf with power slice/slit seeder

What is a slit seeder, and why should you consider using one? A slit seeder is a spreader fitted with vertical blades that plants grass seed 1/4 to 1/2 deep into the soil. That’s the best seed-to-soil contact you can expect and a recipe for successful lawn seeding. 

Does your lawn need its magic? It depends on what you’re planning. Read this article to find out how a slit seeder looks and works, how to use it, and when it’s the best time to put it to work on your lawn.

What does a slit seeder look like

Also known as a “slice seeder,” “vertislicer,” “drill seeder,” and “lawn renovator,” a slice seeder is about the size of a self-propelled push mower. The two lawn care tools look similar, but slice seeders have different fittings:

  • Vertical blades instead of horizontal ones like mowers
  • A seed hopper instead of a grass clippings bag.

In fact, slice seeders are often described as verticutters with a seedbox mounted on top. 

A typical slit seeder includes the following components:

  • A comfortable handlebar to help you drive the seeder across the lawn. Controllers for back and forward movement and managing seed flow are often positioned close to the hands for easy reach. Some models have foldable handles to save storage space, such as the S22 BlueBird Seeder.
  • A sturdy metal frame provides support for the other components.
  • Vertical cutting steel blades or disks roll under the slice seeder’s belly, grinding through the thatch layer and digging slits into the soil. It’s in these slits that seeds are pushed to ensure optimum seed-to-soil contact. 
  • A depth adjustment mechanism, usually a level, allows you to set the depth at which the blades slice into the soil.
  • A seed hopper is mounted on top of the frame, toward the front or the rear. It is a bin with a lid where grass seeds are stored, safe from debris and moisture.
  • The seed mechanism – a mixer placed at the bottom of the hopper leads the seeds out of the bin. It’s connected to a seed dial that allows you to set the seed delivery rate. The mixer is on the same axle as two of the wheels, allowing it to synchronize with the ground speed.
  • The engine (electric or gas-powered) is mounted rear or front. It’s the slice seeder power source and keeps the seed mechanism and the slicing blades moving.
  • Four wheels (Classen has some six-wheel models), pneumatic or made of solid rubber.

How does a slit seeder work?

The slice seeder blades cut grooves into the ground 1.5 to 2 inches apart and up to 1 inch deep while the hopper drops the grass seed. 

Inserted seeds have optimum seed-to-soil contact and offer faster and better seed germination. It’s why experts such as Margaret Hagen, a University of New Hampshire Cooperative Extension field specialist, consider a slit seeder “the best tool for seeding.”

A clear illustration explaining slit seeding
Infographic by Juan Rodriguez

The slit seeding process can happen in two ways:

  • Turf seeders with a front hopper spread the seeds right before the blades, providing follow-up soil coverage. When blades dig into the soil, they push the grass seed into the slits. 
  • Models with a rear hopper have the blades positioned before the seed spreader. These slice seeders first dig the furrows and then spread the seeds, trying to direct them into the slits. Some lawn renovators, like Ryan Mataway models, follow with a second row of circular blades. They direct the seeds into the slits and cover them with dirt.

Which method is better? The general opinion is that models with a rear-mounted seedbox do better than those with a front seed drop. 

Experts agree. Debra Ricigliano, certified professional horticulturist at the University of Maryland Extension, Home and Garden Information Center (HGIC), says, “When renting a slit seeder, check to be sure it deposits the seed after it makes the groove and not before.”

What are the benefits of using a slice seeder?

In a nutshell, the main benefits that make slice seeders stand out from the mass of grass-seeding machines are:

  • Optimum seed-to-soil contact
  • Faster germination
  • Higher sprouting rates
  • Uniform, thick turfgrass
  • Better seed protection: seeds covered with soil are safe from birds and heat

Sounds amazing, but these benefits also come with some drawbacks. To get a clearer image of what a slit seeder can and can’t do for your lawn, we compare its pros and cons with those of a traditional overseeder.

Slice seeder vs. traditional overseeder

“Is slice seeding better than traditional overseeding?” is a question every homeowner asks at some point in their turf grass growing adventure. The answer is not a simple yes or no; there are pluses to both seeding methods and tools. Here’s what lawn care pros and passionate DIY homeowners say when evaluating the two. 

Slice seeder pros and cons

Pros:

  • Good quality slice seeders can ensure optimum seed-to-soil contact and a higher germination rate. 
  • Slice seeding grows more uniform and thick lawns.
  • Seeds inserted into the soil have better access to moisture and nutrients. They are also safer from heat, birds, and heavy rain runoff.
  • Slice seeding speeds up germination, providing faster sprouting.
  • It offers better results for slightly sloped lawns by setting the seeds firmly into the soil. 
  • Using a slice seeder also can reduce the use of toxic herbicides on your lawn. As M. Bess Dicklow explains, “Overseeding with a slice seeder when lawn quality deteriorates replenishes desirable turfgrasses and produces a denser lawn that can out-compete weeds.” 

Cons:

  • It’s a specialized tool, more expensive to rent or buy (few lawn owners have one in their garage).
  • Requires experience to use it with good results.
  • It comes with high risks of failing to cover the lawn properly.
  • It can have poor results on uneven terrain. Bumps in the lawn can prevent blades from digging into the soil properly.
  • Slice seeding is a specialized service that only some lawn care companies offer.

Regular overseeder pros and cons

Pros:

  • Accessible and popular equipment. Many homeowners have a drop or broadcast seeder or can easily find one to rent or buy.
  • Less expensive equipment.
  • Easier to use. Requires less experience and comes with a lower risk of error.

Cons:

  • Requires extensive soil preparation. You must clear debris, remove the thatch layer, core aerate, mow, and apply a topdressing before seeding.
  • Results depend highly on how well you prepare the seeding bed.
  • Lower seed-to-soil contact.
  • Seeds must be protected from dryness and birds with straw mulch.
  • Germination time is longer.
  • Lawns don’t grow as dense and uniform.

When to use a slit seeder

Slits in fescue lawn turf from power slice/slit seeder
Shutterstock

When deciding if slice seeding is the way to seed your lawn, consider the following:

Lawn seeding purpose

Slice seeding machines are high-impact tools better used when:

  • Installing new lawns.
  • Repairing heavily damaged areas in existing turf, such as large brown patches and bare spots.
  • Overseeding overly thinned lawns.
  • Transitioning the lawn to a different type of turf.
  • Renovating an entire lawn – removing all vegetation (weeds and grass) and replacing it with new grass.

Slice seeders cost more to rent or buy and are more difficult to use than regular overseeders. That’s why lawn owners often replace it with the traditional approach (aeration and overseeding) when:

  • Routine overseeding spreading new grass seeds over a slightly thinned, healthy lawn as part of the annual lawn care practices.
  • Reseeding small patches or bare spots. In this case, manually spreading the seed ensures the most precise application.
  • Dormant seeding the lawn. As Glenn Hardebeck, turfgrass research agronomist at the Department of Agronomy of Purdue University, explains: “Dormant overseeding does not require mechanical cultivation (slit-seeding or power raking) to get the seed into contact with the soil. With dormant overseeding, Mother Nature will ‘plant’ the grass seed with repeated freeze/thaw cycles.”

Lawn size

Slice seeders are a good choice for planting grass on a small- to medium-sized lawn. Most residential lawns are a good fit for slice seeding.

On large lawns, slice seeding is time-consuming, and broadcast spreaders are often a better choice.

The best time of year for slice seeding

For cool-season grasses like Kentucky bluegrass, fescues, and ryegrass, the best time to plant new turf is late summer to early fall (though you can also seed in early spring if you missed the fall window). 

If you plan to slice seed warm-season grasses like Bermuda, Zoysia, and St. Augustine, do so from late spring to early summer.

How to use a slit seeder 

Because of the blades that cut through thatch and topsoil, slide seeders often require less preparation than a broadcast or drop seeder. But you’ll still need to take care of some details to ensure a successful seeding.

What to do before turning on the slice seeder

  • Measure the area you plan to seed and determine the right amount of grass seed you need (check our guide on overseeding for the detailed steps).
  • Buy a suitable grass variety. Consider upgrading to a more resilient turfgrass if the lawn has trouble dealing with the climate, soil type, or local pests and diseases.
  • Wear protective gear, including safety glasses, work gloves, hearing protection, and durable work boots.
  • Keep pets and children away from the area while working.
  • Clean the lawn. Remove stones, twigs, hoses, toys, pots, and any other debris that might get in the way.
  • Mow the lawn shorter — about 1 to 2 inches tall, depending on the type of grass — to provide the best machine-to-soil contact. Do it in more mowing sessions, cutting no more than ⅓ of grass height each time (an essential mowing rule). Collect the grass clippings.
  • Mark sprinkler heads and tree roots with flags or sticks to avoid passing over them.
  • Remove the thatch layer if it is thicker than 2 inches.
  • Core aerate the soil if it is compacted. Lawn care professionals recommend two to four passes with the aerator for highly compacted clay soil.

How to spread grass with a slit seeder

Each slit seeder is a bit different: Read the user manual that came with your model for precise instructions. The process is similar to broadcasting grass seed or spreading fertilizer, except you must also manage the blades. Here are the general steps you should follow when using a slice seeder:

Step 1: Feed the slice seeder some fuel so you can seed the lawn without interruption. Check if the blades are up, then drive the seeder toward the lawn.

Step 2: Fill the dropbox with the proper amount of grass seed.

Step 3: Set the seeding rate. Each slit seeder has a graphic with recommended seeding rates per type of turf seed. Look for the specific seeding rate for your grass.

You’ll make two passes over the lawn, so divide the recommended rate by two. Calibrate the seeder by setting the seed dial to the correct value.

Step 4: Set the blade depth. You’ll find specific instructions on the slit seeder and the grass seed package. 

According to the USDA Natural Resources Conservation Service, Plant Material Center, “Most species should be planted at a shallow depth of ¼ to ½ inch. Larger seeds can be planted up to 1 inch deep. Most seedings are too deep if you cannot see a few seeds on the soil surface.”

Step 5: Start spreading the seed from one corner of the lawn. Walk the slicer straight toward the other edge of the lawn. 

Turn off the seed spreader when you have to turn around. Make a tight turn, reopen the hopper’s discharge port and walk back, slightly overlapping on the previous seeded strip. 

Continue until you cover the entire lawn.

Step 6: Do a second pass perpendicular to the initial direction or at a 45-degree angle. This ensures even application and a dense turf. 

What to do after slit seeding: 

  • Slit seeders tend to pull out lots of thatch with their blades. Spread the thatch uniformly with a rake to form a thin cover for your seeds. It will protect them from heat, direct sunlight, and birds. 
  • Where thatch is thick or gathered in clumps, rake the dead organic matter away from the lawn. A thick layer of thatch can hinder or stop germination and sprout growth.
  • Spread a starter fertilizer and water it properly into the soil. Starter fertilizers are rich in phosphorus and essential for your new grass to grow deep, healthy roots.

Do you need to water after slice seeding? Absolutely. Without water, new grass seeds don’t germinate. 

  • Irrigate the lawn to moisten the topsoil 2 inches deep. 
  • Water the grass seed two to four times a day for 5 to 10 minutes for the next two weeks (until most seeds germinate). Apply ⅛ to ¼ inches of water daily. 
  • When the lawn has mostly greened up, gradually reduce the frequency until you reach the regular watering schedule: once or twice a week with 1 to 1.5 inches of water.

What’s the best way to slit seed your lawn? The best way to slit seed is to invest proper time in preparing the seed bed. Homeowners tend to skip some steps because a turf slit seeder offers good results, even with some soil compaction and thatch over the lawn.

If you want the best results, follow every step thoroughly: 

  • dethatch if a thick layer covers the lawn 
  • core aerate compacted soil
  • mow the grass short
  • rake the lawn to expose the soil and ensure the best seed-to-soil contact

Slice seeder cost: buying vs. renting vs. hiring a pro

Buying a slice-seeder

Most slice seeders cost between $2,000 and $5,000 to buy. It’s a big investment, and it’s rarely worth it just to slit seed your lawn once every few years. For residential projects, renting a slice seeder is the better and more practical option.

Slice seeder rental

If you decide to slice seed your lawn DIY, you can rent a good seeder from home improvement stores such as Home Depot or Lowes. The average rental fee for a gas-powered slit seeder ranges between $60 to $65 for 4 hours or $90 to $95 a day. 

Slice seeder models available for rent include:

How long does it take to slice seed a lawn? Most residential lawns can be slit-seeded in less than a day. 

Note: You might pay a higher price to rent a slit seeder if you don’t have time to seed during the week and you’re getting the weekend rate. 

The tow-behind spiker seeder option

With an average cost of $250 to $800, residential tow-behind spiker seed spreaders are good for seeding small to medium lawns with a thin thatch layer and mildly compacted soil. 

They are lawn tractor attachments with 10 to 12 star-shaped blades (like spike aerators have) installed under a drop spreader. 

Professional slice seeding cost

Another option is to hire a lawn care pro with slice seeding experience to repair the turf or install a new lawn for you.  You can expect to pay about $0.08 to $0.18 per square foot to slice seed the lawn. 

How to choose a slice seeder

Let’s say you don’t invest in a slice seeder but are willing to rent one and try a DIY. How would you choose among the available models? 

Self-propelled or push seeder: For small, leveled yards, a push slice seeder can do the job even if it takes a bit more effort to drive back and forth. If your lawn is medium- to large-sized or sloped, consider a self-propelled slit seeder.

Seeding width: Most residential models have a 19- to 24-inch seeding width. Choose a smaller width for a small-sized lawn or turf with many trees and shrubs you’ll need to get around. Go for a broader model on a large, 100% turfgrass lawn.

Slice seeder brands: The most popular slice seeder brands include:

  • Mataway 
  • Toro 
  • Classen
  • Exmark
  • Bluebird
  • Lesco

The most affordable options are Classen, Bluebird and Toro.

Slit seeders as multipurpose machines

Some slit seeders have interchangeable blades allowing the machine to be used for multiple lawn care tasks. 

The most common types of blades are:

  • Flail blades: small and thin, these blades are used to treat moderate thatch levels. They are the most suitable for overseeding and existing lawns with healthy, deep-rooted grass.
  • Deep slicing blades: thicker and longer, used for thatch layers that are ½ inch thick or more. 
  • Spring tines: thin, nail-like blades used for power raking and the annual routine dethatching.
  • Vertical slice blades: the most robust, used to cut through surface root grasses.

Can you use a slice seeder as an aerator? 

Not quite. Core aerators have larger tins that dig deeper into the soil (up to 4 inches deep). They pull out small soil plugs, leaving behind many tiny holes that help water and nutrients reach easier into the soil and feed your lawn’s roots. Core aeration also loosens the ground and promotes deeper root systems for your new grass.

By comparison, slice seeders only scratch the surface (their blades dig up to 2 inches deep). The soil remains compacted all around the furrows where seeds are planted, limiting root development. 

Can you use the slice seeder as a dethatcher? 

Yes, you can. The steel blades the slice seeder uses to grind trenches into the soil are similar to those used by a standard lawn dethatcher. 

To dethatch with a slit seeder, simply remove the seed box or leave it empty. Run the seeder across the lawn with the blades lowered enough to cut the thatch layer but not to go more than ½ inch into the soil to avoid damaging the lawn’s roots.

Can you use the slice seeder as a power rake?

If the model you bought or rented also has spring tines, you can use the slice seeder as a power rake to pull out the thatch layer. Just remove the seed box or run the seeder with the seed box empty if it is not removable.

FAQ about slice seeders

What is a three-point (3Pt) spreader?

A three-point spreader can spread grass seed in three different patterns: 

  • predominantly right
  • predominantly left 
  • both right and left 

These models are usually used as attachments with farming, gardening, or landscaping tractors.

Can you use a slit seeder on wet soil?

Driving a slit seeder on wet soil is not a good idea. It might seem so because the grooves it makes are so well-defined, but it’s not what you need. You need the soil dry enough to fall back and cover the seeds. Also, running heavy machinery on a wet lawn is a sure recipe for soil compaction.

Is a slit seeder worth it?

It depends on what your lawn needs. Slit seeders do a great job in repairing highly damaged lawns and installing new ones. If you’re planning a lawn renovation, it’s worth renting one or hiring a pro to slice seed new grass. 

However, if you have only a few bare spots on your lawn or the turf is a bit thin, you can get great results with lower costs by using regular overseeding.

Enjoy a thick, healthy lawn in a few weeks!

A slice seeder is the most effective way to repair a damaged lawn with dense, healthy grass. If you love the results it can bring but dread learning how to manage such a tool from scratch, don’t worry — you don’t have to! With Lawn Love, you find the best local lawn care pros with slice seeding experience in a jiffy. choose your pro and enjoy the thickest lawn you’ve ever seen!

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Main Image Credit: Shutterstock

Sinziana Spiridon

Sinziana Spiridon is an outdoorsy blog writer with a green thumb and a passion for organic gardening. When not writing about weeds, pests, soil, and growing plants, she's tending to her veggie garden and the lovely turf strip in her front yard.