Slice seeding is the magic you need to convert your patchy lawn into a thick green carpet without waiting an entire growing season. It’s a precise grass-seeding method that digs narrow grooves, pushing grass seeds directly into the soil for the best seed-to-soil contact. You’ll get up to 90% germination rate, faster sprouting, and a dense lawn you’ll absolutely love.
What’s the catch? Slice seeding can be difficult to DIY, it can be more expensive than traditional overseeding and is not ideal for all lawn reseeding situations. Read on to learn all about slice seeding, including what slice seeding is, how it works, and when to use it.
What is slice seeding?
Slice seeding is the most efficient technique for reviving damaged or worn-out lawns. You’ll also find it referred to as “slit seeding” or “power seeding.” This seeding method uses a slice seeder machine (aka slit seeder), to dig the seedbed and spread the seeds in well-organized rows. Slice seeding is about the most precise reseeding technique you’ll find and creates the dense turf all homeowners dream of.
How does slice seeding work?
Slice seeders have rolling blades that cut parallel, narrow grooves into the soil up to 1 inch deep. Seeds go through several tubes and land directly into the freshly made furrows. With the topsoil loosened and grooves to land in, seeds enjoy the best seed-to-soil contact you can expect.
You can use this method on bare soil, or on established lawns. The seeder disks cut through thin thatch and vegetation, making lawn renovation easy and fast.
Pros and cons of the slice seeding technique
While slice seeding’s advantages outweigh its disadvantages, you need to see it from all angles before choosing it to improve your lawn’s look. Here are the main pros and cons of slice seeding:
Pros of slice seeding
- High seed germination rate: Slice seeding has a germination rate of up to 90% with proper soil preparation and watering. The high rate is due to the excellent seed-to-soil contact. By comparison, traditional overseeding has a 15% to 30% rate.
- Seed protection: The grooves housing the seeds and the mulch you leave on top protect the seeds from animals, birds, and heat.
- Uniform seed spreading: Compared with traditional seeding, slice seeding offers better uniformity. You’ll enjoy a thick lawn without clumps of denser turf or thinner spots.
- Dense lawns: Slice seeding places seeds in well-defined rows and ensures a uniform distribution of seeds. This makes lawns planted with a slice seeder incredibly dense compared to other seeding methods.
- Fast results: Seeds spread in grooves have better access to water and nutrients and tend to sprout faster. With almost all seeds germinating, you’ll see the lawn covered in a thick, green carpet in a few weeks.
- Weed control: Slice seeding creates dense, thick lawns that keep weeds at bay. It reduces the need for herbicides, saving money in the long term.
- Best method for renovating lawns: Slice seeding provides fast sprouting and thick grass, quickly reviving dry patches and bare spots.
Cons of slice seeding
- Specialized machine: Slice seeding requires a specialized machine. You’ll need to rent if you want to DIY. Slice seeder rental costs are about $90 for one day. Since it’s not as popular as a regular seed spreader, this machine is also a bit harder to find.
- Requires experience: There is more than one way to get a DIY slice seeding wrong. You can use the wrong settings for seeding rate and depth. Or you might not lead the seeder properly on the site and get bare spots and thick clumps. Most homeowners hire a lawn care professional for this type of seeding.
- Soil compaction limits results: Slice seeders dig shallow grooves that help germination. If the soil underneath is compacted, the new grass can’t develop proper roots. You’ll see a good germination rate but slower and less healthy grass growth. Aerate compacted soils before seeding to get the best results.
- Less suitable for large areas: Slice seeding is a labor-intensive process. It’s effective on the average-sized lawn but time-consuming and costly on larger properties.
- Too costly for routine maintenance: Slice seeding is a high-impact method. It’s better used for lawn renovations and repairs and less for routine overseeding. On a healthy lawn that only needs its annual overseeding, slice seeding is too costly for its results.
- Ineffective against invasive grasses: Slice seeding by itself can help fight off unwanted grasses like tall fescue, creeping bentgrass, or rough bluegrass. But if such problem grasses are overtaking your chosen turf, it’s best to remove them with a sod cutter or herbicides before slice seeding.
When to slice seed your lawn
Slice seeding is an intensive lawn seeding method. It cuts through the topsoil and creates thick, dense lawns. The best way to use its power is when renovating or repairing a lawn. Among the situations when a lawn care professional would recommend slice seeding, these are the most common:
- Treating weed-invaded areas with herbicide and replanting the chosen turfgrass
- Reviving a lawn covered with dry, bare patches
- Reseeding a lawn that is overly thinned, with only 70% healthy grass or less
- Removing one type of turf from the lawn and replacing it with a more resilient one
- Installing a new lawn.
When is slice seeding less suitable? Slice seeding is not the best option for reseeding a healthy lawn. Simply put, it’s too much work and money for such a basic job. In this case, traditional overseeding offers the best cost-benefit results. Plus, the slice seeder can harm some of the existing grass in your established lawn while cutting into the ground to spread the new seeds.
Slice-seeding vs. traditional overseeding
Traditional overseeding uses a drop or broadcast spreader to apply grass seeds on the soil surface. It’s the most affordable method and easy to use DIY on small to large areas.
On the downside, it provides a lower germination rate of 15% to 30%. Germination rates can be improved by properly preparing the seedbed through aeration, dethatching, and topdressing. This way, you improve seed-to-soil contact and ensure loose soil for air, nutrients, water, and roots to penetrate more easily.
When to choose traditional overseeding: Routine annual reseeding to keep a healthy lawn at its top thickness. Repairing thinned patches and small bare spots on an existing lawn.
When to choose slice-seeding: When repairing large, numerous brown patches in need of a complete makeover. Also, when reseeding thinned lawns with less than 70% healthy grass. It’s the best choice for sloped lawns.
Slice seeding vs. hydroseeding
Hydroseeding uses a liquid mix of water, seeds, mulch, fertilizer, and sometimes biostimulants. The mix is sprayed over the bare ground with a hydroseeder and a hose, ensuring uniform coverage and good seed-to-soil contact.
Hydroseeding offers high germination rates, similar to slice seeding. It’s the go-to lawn seeding method for large areas, installing new lawns and seeding sloped terrains. On the downside, it’s costly for small and mid-sized yards, only works on bare ground, and DIY applications have poor results.
When to choose hydroseeding: Installing a new lawn or renovating the entire lawn in a large yard. Turfgrass planting on sloped lawns.
When to choose slice-seeding: Renovating bare patches, repairing overly thinned lawns, replacing turf type, or installing a new lawn into a small to mid-sized yard.
Slice seeding costs and expectations
Due to the specialized equipment and the experience required for good results, slice seeding can be more costly than the regular overseeding. Here’s what to expect.
Slice seeding costs
It costs $0.08 to $0.18 per square foot to slice seed a damaged lawn. This means you’ll pay about $400 to $900 to renovate a 5,000-square-foot area. These costs don’t include aeration, yard cleaning, or other type of preparation your lawn needs before seeding.
If you’re familiar with using lawn care machinery and plan for a DIY project, you’ll pay $60 to $90 to rent a slice seeder for 4 hours to a whole day.
How long does it take to slice seed a lawn?
While labor-intensive and typically a double-pass process, slice-seeding doesn’t take long. The average residential lawn and small commercial projects can be done in less than a day.
How long does it take to see results?
Depending on the seed germination time, you can expect to see a beautiful, dense (but still short) green carpet in about a month.
Slice-seeding germination rate is up to 90%, so the grass that sprouts will be dense and cover your lawn nicely. Compared to traditional overseeding, you won’t have to wait for stolons or rhizomes to extend and cover thin spots where seeds fail to sprout.
How to slice seed step-by-step
Step 1: Decide the best time to slice seed the lawn. For cool-season grasses (like tall fescue and Kentucky bluegrass) it’s late summer to early fall, while warm-season grasses are best seeded in spring and early summer.
Step 2: Measure the area and buy the proper amount of herbicides (if needed), grass seeds, and starter fertilizer. Rent a slice seeder for when you plan to seed your lawn.
Step 3: Spread herbicide if you need to remove weeds or unwanted grass from the area. Follow the product instructions carefully and wear protective equipment. Keep kids and pets away while working and for a few hours after application.
Step 4: Aerate if the soil is compacted. Professional lawn aeration ranges from $82 to $251.
Step 5: Mow the lawn short. Set the lawn mower blades 1 to 2 inches high and mow the lawn shorter than usual. Rake the grass clippings afterward and take them off the lawn.
Step 6: Fill the hopper with grass seeds. You’ll make two passes, so set the seeding rate to half the one indicated on the seed bag or the slice seeder. Then, set the seeding depth, which is also present on the seeder or on the seed package.
Here are some general seeding rate recommendations for the most popular turf types to guide you:
| Type of grass | Seeding rate per 1,000 sq. ft. |
| Bahiagrass | 5.0 to 10.0 |
| Bentgrass | 0.5 to 1.0 |
| Bermudagrass | 2.0 to 4.0 |
| Buffalograss | 1.0 to 3.0 |
| Carpetgrass | 3.0 to 5.0 |
| Centipedegrass | 0.5 |
| Fine fescue | 3.0 to 6.0 |
| Kentucky bluegrass | 2.0 to 3.0 |
| Perennial ryegrass | 3.0 to 5.0 |
| Tall fescue | 5.0 to 6.0 |
| Zoysiagrass | 1.0 to 3.0 |
If there’s still up to 50% healthy grass on the seeded area, use half the recommended rate. Keep in mind seeding rates may vary with cultivar and when using turf blends or mixtures.
Step 7: Lead the slice seeder across the lawn, starting from one corner. Walk steadily in a straight line, back and forth (north to south). Slightly overlap the seeding rows to avoid bare spots. When you finish the first pass, do the second one crosswise (east to west).
Step 8: Check the layer of thatch the seeder broke out while cutting the soil. Leave it be if it is uniform and less than 1 inch thick. It protects the seed from birds and dryness. Where in large clumps of 3 to 4 inches thick, rake it or spread it with a blower to get a uniform cover of your seed bed. Too much coverage can hinder grass growth.
Lawn maintenance after slice seeding
Once the grass seed is in the ground, ensure it has everything for successful germination and grass growth.
Apply a starter fertilizer: Most lawn care experts recommend spreading a starter fertilizer after seeding. Starter fertilizers provide a balanced nutrient mix with phosphorus for healthy root growth. Use a broadcast spreader to ensure uniform dispersal and follow the application instructions on the product label.
Keep the seeds from drying out: Water the seeded area daily during the first two weeks or until the entire lawn has sprouted grass. Irrigate once in the morning and again in the afternoon if the soil shows signs of dryness. Apply 1/4 to 1/2 inches of water daily. Reduce irrigation gradually after germination. Water once a day in the third week and once every other day in the fourth week.
Strengthen the grassroots: After a month, your grass has roots, but they’re still shallow and weak. Now you need to strengthen them. Start watering once or twice a week with 1 to 1/5 inches of water weekly. Irrigate deeply, so they moisten 6 to 8 inches deep. This watering strategy promotes deep, strong roots and improves your grass’s resilience to drought.
Don’t rush the first mow: Start mowing only after the grass has reached 1.5 times its recommended mowing height. See below how tall your new turf should be before the first mowing session by grass type:
| Type of grass | Height before first mowing |
| Bahiagrass | 2-2 ½ inches |
| Bentgrass | 1 inch |
| Bermudagrass | 1½-2 inches |
| Buffalograss | 2-3 inches |
| Carpetgrass | 1½-2 inches |
| Centipede | 1½-2 inches |
| Fine Fescue | 2-3 inches |
| Kentucky Bluegrass | 2-2½ inches |
| Perennial ryegrass | 2-3 inches |
| Tall fescue | 3-3½ inches |
| Zoysiagrass | 1-2 inches |
Always follow the three mowing rules:
- Don’t mow more than ⅓ of the blade height.
- Avoid mowing wet grass.
- Keep your lawn mower’s blade sharp.
How to improve slice seeding results
You can improve the slice seeding results by investing more in preparing the lawn soil for seeding.
Aeration before slice seeding
Is aeration a must with slice seeding? If the soil is compacted, yes. Slice seeder blades only break the soil surface and ensure good soil contact with the seed. If the soil underneath the groove is compacted, the young plants won’t be able to penetrate and develop strong, deep roots.
Aeration before slice seeding is especially important with clay soil which is prone to soil compaction. You can hire a pro to core aerate your lawn for $82 to $251.
Dethatching before slice seeding
Should you dethatch before slice seeding? If your lawn is covered in thick thatch, yes. Slice seeders can cut effectively through thin thatch and deposit their seeds into the soil. But if the layer is too thick, some seeds might get caught in the dead vegetation.
You can use most slice seeders as dethatchers if you pass the blades over the lawn with an empty seed box. Hiring a pro to dethatch the lawn costs $0.04 and $0.06 per square foot.
Soil amendments
You can ensure the new grass has all the resources for healthy growth by testing the soil and applying any necessary amendments. Soil pH takes time to adjust, so plan the soil test and pH treatment a few months before slice seeding. To treat acidic soil, use lime; to improve an alkaline lawn, use sulfur.
The soil test also will show you any nutrient deficits and what fertilizers to use.
FAQ about slice seeding
What is aeration and overseeding?
Aeration and overseeding is a traditional grass-seeding method. Core aeration pulls out tiny cores of soil across the lawn improving soil texture, airflow, and nutrient and water absorption. It often precedes overseeding to improve seed-to-soil contact. Overseeding is spreading grass seed across the soil surface. It’s the most popular reseeding technique and easy to DIY.
Do you need to straw after slit seeding?
It depends on the lawn you plan to slice seed:
- If you slice seed dead patches on an established lawn, you don’t need to straw after seeding. Slice seeding cuts out thatch and dead grass you can use to form a thin protective layer over the seeds, replacing straw.
- If you install a new lawn and slice seed on bare ground, yes, it would help to straw. Spreading a thin layer of straw can protect seeds from birds and animals.
How often should you slice seed?
Slice seeding is not exactly a routine seeding technique, and its use should depend on the state of your lawn. This being said, if your lawn doesn’t respond well to regular overseeding, consider slice seeding once every two or three years to get its thickness back.
When to call a lawn care professional
Now you know what slice seeding is and when it’s most useful for your lawn. Don’t postpone repairing the brown patch any longer. Use Lawn Love to find a lawn care expert in your area to slice seed your lawn and enjoy the thick, lush turf you’ve always wanted!
Main Photo Credit: Adobe Stock
