Topsoil for Lawns and Raised Beds: How Much, What Kind and How to Spread It

How much topsoil you need

Topsoil is sold by the cubic yard. A cubic yard is 27 cubic feet, and spread 1 inch deep it covers about 324 square feet. Penn State and New Mexico State both call for 4 to 6 inches of topsoil for a lawn, measured after it has firmed or settled, and UConn Extension states roughly 12 cubic yards covers 1,000 square feet at 4 inches deep.

Worked example, new lawn: an area 20 feet by 30 feet is 600 square feet. At 4 inches, 600 x 4 = 2,400, and 2,400 / 324 = 7.4 cubic yards. Add about 10 percent for settling and uneven grade: 7.4 x 1.1 = 8.1, so order about 8 cubic yards. At 6 inches the same lawn needs 11.1 cubic yards, or about 12.2 with the extra 10 percent.

Worked example, raised bed: a frame 4 feet by 8 feet and 12 inches deep holds 4 x 8 x 1 = 32 cubic feet, or 1.2 cubic yards. If you use a 1:2 compost to topsoil mix, which is one of the ratios University of Maryland Extension gives for compacted or clay soil, that is about 11 cubic feet of compost and 21 cubic feet of topsoil, plus an allowance for settling.

If you are only adding topsoil to an area that already has some, measure what you have. Penn State's target of 4 to 6 inches is total depth after firming, not the amount to add on top of whatever is there.

Choosing the right type: topsoil, garden mix or compost

The three products do different jobs, and the labels are not regulated. University of Maryland Extension says the state does not regulate topsoil sales, and UConn says topsoil has no standard grade. Inspect before you buy.

• Screened topsoil: native mineral soil that has been put through a screen, commonly 3/4-inch mesh according to UConn. Screened topsoil should contain no rock fragments over 3 inches, and gravel should be no more than 5 percent of the volume. It is the right product for building up grade and for lawns.
• Manufactured or blended topsoil: UConn describes it as a coarse, sandy mineral base mixed with composted organic material. It can be useful, but not all of it is good enough to use as topsoil.
• Garden mix and bagged soil: Maryland Extension says bagged organic soil is usually not topsoil at all, but wood waste, bark fines, compost and peat. Some topsoil and compost blends from landscape suppliers work well as raised bed media.
• Compost: an amendment, not a substitute. University sources use it to raise organic matter, with Maryland Extension giving a target of 25 to 50 percent by volume in raised bed soil. It can also be used for thin topdressing of lawns.
• Texture to look for: UConn ranks sandy loams and fine sandy loams as best, loams and silt loams as acceptable at no more than 4 inches where traffic is light, and sands, clays and silts as soils to avoid. Missouri Extension names loam and silt loam as ideal and a pH of 5.5 to 7.5.

What to buy

Decide the job first, because a lawn, a patch repair and a raised bed need different products.

• Screened topsoil that matches the soil already on site where possible, free of trash and rocks over 3 inches.
• Organic matter of about 2 to 10 percent (UConn) or at least 3 percent (Missouri). Be suspicious of very dark, grayish soil, since UConn says it may have been dredged from wetlands and is often acidic and poorly structured.
• A soil test, either of your existing soil, the topsoil pile or both. UConn notes few sellers test their product, and Missouri says a test is the most reliable way to judge quality, especially for large amounts.
• Mature, screened compost for amending, and mushroom compost only after a soluble salt check (UConn).
• Starter fertilizer and lime only at the rate the soil test recommends.
• Tools: a grading rake, shovel, wheelbarrow, lawn roller for firming, and a tiller if the subsoil is hard.

Preparing the site

Start with the soil test. Penn State advises taking samples three to four weeks ahead so the results arrive in time, and Virginia Tech says to retest if it has been more than 3 years. Maryland Extension says to use a lab test rather than a home kit, and to test for lead if you will grow food, with a limit of 400 ppm total lead for vegetables.

Clear debris. New Mexico State says to remove building materials, buried stumps and stones larger than 2 to 3 inches, and to haul away debris found during grading instead of burying it. Kill or remove existing vegetation; NMSU describes using a nonselective herbicide and waiting about 7 days before disturbing the sod.

Grade soil to fall at least 6 in over the first 10 ft (5%) away from the foundation, and keep soil at least 6 in below siding. Paved or stone surfaces need about 2% (1 in per 4 ft). Confirm against your local code or extension office.

Mix the layers. Penn State says to work about 2 inches of topsoil into the top 2 to 3 inches of subsoil, which eases the change between layers. NMSU says to rototill to at least 6 inches.

Step by step: new lawn or large area

• 1. Test the soil and order topsoil, compost and any lime or fertilizer the report recommends.
• 2. Clear debris and weeds, then rough grade so water runs away from the house.
• 3. Loosen the subgrade with a tiller, ripper or chisel plow if it is compacted.
• 4. Have the topsoil dumped on the area, or at the edge, and spread it with a rake or a blade, working to the depth stakes you set earlier.
• 5. Mix the top 2 to 3 inches of existing subsoil with the new topsoil where you can.
• 6. If the test calls for compost, spread it in layers of 1 to 2 inches and till it 4 to 6 inches deep (Penn State).
• 7. Firm the soil when it is fairly dry with light equipment, or let rain or irrigation settle it and wait several days for it to dry (Penn State). NMSU suggests settling with 0.5 to 1 inch of water first.
• 8. Fine grade with a rake: remove stones over 2 inches, smooth high and low spots, then seed or sod.
• 9. Apply starter fertilizer at the soil test rate. Penn State gives 0.5 to 1 lb of nitrogen per 1,000 square feet and warns that more than 1.5 lb can burn young turf.

How deep and how to finish

For a lawn the minimum depth is 4 inches according to Penn State and NMSU, and NMSU recommends 6 inches or more for deeper roots, since shallow soil can hurt appearance and increase water use. Measure depth after firming, not after the dump.

Penn State says to till moist soil to at least 4 inches in one or two passes, since over-tilling pulverizes it and causes surface crusting and a poor seedbed.

Timing: Penn State puts the best seeding windows in mid-to-late spring and late summer to early fall, with late summer optimal, and says late-fall seeding is risky because cold soil prevents germination. Virginia Tech calls fall the best time to establish cool-season grasses by seed or sod. Sod can be laid any time the soil is not frozen. Warm-season grasses follow a different schedule.

Lawn repair and topdressing

Existing lawns need thin layers, not a blanket of topsoil. Clemson says to apply no more than about 1/2 inch at a time, because thicker layers can stunt or shade the turf, and Virginia Tech uses about 1/4 inch of quality compost over a seeded area. Rake the material in so it sifts between the grass blades without covering them.

For bare spots, Virginia Tech says problem areas are often 50 to 150 square feet, so renovate only those. At a minimum, disturb the surface with multiple passes of a core aerator or power rake, because scattering seed on unprepared soil fails. Sod is an option for spot repairs and tolerates light traffic sooner.

To fill low spots, Clemson says to use topsoil that matches the native soil or sand only if the native soil is sandy. It also warns that topsoil can bring in weed seeds, so you may have a new weed problem after a topdressing.

Raised bed fill

Utah State says framed boxes should be at least 6 to 12 inches high, and boxes shallower than 12 inches should have no bottom so roots can reach the native soil. It recommends tilling the native soil 6 to 12 inches deep before building.

Utah State gives two mixes: native topsoil amended with 30 to 50 percent compost by volume, or equal parts compost, drainage material such as coarse sand or perlite, and topsoil. Maryland Extension gives 1:2 or 1:1 compost to topsoil for compacted soil, and 1:1 compost and soilless mix for beds on hard surfaces, where topsoil can be up to 20 percent by volume only if the bed is at least 16 inches deep.

On hard surfaces, Maryland Extension sets minimum depths of 8 inches for leafy greens, beans and cucumbers, and 12 to 24 inches for peppers, tomatoes and squash. Loosen soil with a fork instead of flipping it.

Common mistakes

• Skipping the soil test and guessing at lime and fertilizer.
• Accepting topsoil sight unseen. Maryland Extension says to avoid soil that is very sandy or clayey, smells foul, shows gray mottling, or feels chalky, sticky or rough.
• Spreading topsoil over compacted subsoil without loosening or mixing it.
• Burying debris or stones instead of removing them (NMSU).
• Smothering an existing lawn under a deep layer of topsoil or compost.
• Using sand to fix clay. Penn State says it takes about 60 percent coarse sand by volume, which is usually too expensive; UConn prefers adding organic matter.

Cost and ordering tips

UConn says topsoil is sold by the cubic yard with a typical minimum delivery of 3 to 6 yards. Smaller jobs, patch repairs and raised beds are often easier with bags, though bagged products are often a different material from bulk topsoil. Work out the number of bags per cubic yard (27 cubic feet divided by bag size) before you compare.

Ask the supplier: where the soil came from, whether it has been tested, whether compost or manure has been added, how it is stored, what screen size was used, and whether you can see the pile. Maryland Extension and UConn both recommend asking for soil test results and visiting the stockpile.

Schedule delivery for when you can spread it. A pile left in rain turns to mud, and a pile left to dry can blow. Have the driver drop it on a tarp near the work area.

Settling and later top-ups

Penn State measures depth after the soil has firmed or settled, so plan for the surface to drop. The sources we read give no settling percentage for raised beds, so we cannot cite one. The practical fix is the 10 percent allowance in your order and a bit held back for topping up after the first heavy rain or watering.

After the first season, check low spots, add thin layers if needed, and retest the soil. Maryland Extension advises retesting a year after a raised bed is filled, once the components have mixed and reacted. Add compost to the bed surface each year to maintain the organic matter target.

Before you start: utilities, permits and safety

Before you dig anywhere, call 811 (the US call-before-you-dig line) a few business days ahead so utility lines are marked free of charge. Check your local rules for permits when you build a shed pad, driveway, wall or change the grade of your lot.

Do not pile soil against tree trunks or raise the grade more than 1 to 2 in over the root zone of existing trees, and keep the root flare visible. Wear gloves and wash your hands after handling soil, and lift bags with your legs.

Common topsoil project sizes

Each row uses the depth shown and includes 10% extra for waste. Change any number in the topsoil calculator.

Frequently asked questions

Sources: Penn State Extension: Lawn Establishment, New Mexico State University: Establishing a Lawn (H-509), UConn: Purchasing Topsoil, University of Missouri: Selecting Good Topsoil, University of Maryland Extension: Soil Fill for Raised Beds, Utah State University: Raised Bed Gardening, Clemson HGIC: Topdressing a Home Lawn, Virginia Tech: Cool Season Lawn Renovation. Read 7 November 2026.