Project guide
New lawn
A lawn is only as good as the ground under it, and that ground is the one thing you cannot fix afterwards without starting again.
- TimeA weekend for the ground, then weeks of watering
- DifficultyModerate, and unforgiving of shortcuts
How much topsoil do I need for a new lawn?
- Topsoil at 4 inches: one cubic yard covers about 81 square feet at 4 inches, so 300 square feet takes about 4 cubic yards (roughly 4 tons).
- Compost at 1.5 inches: one cubic yard covers about 216 square feet at 1.5 inches, so 300 square feet takes about 1.5 cubic yards (roughly 1.1 tons).
What the job involves
Getting the rough grade right and letting it settle, bringing the soil up to depth, blending compost through the top of it, then raking to a finish grade and sowing or laying. The soil is the whole job. The grass is the easy part, and it is also the part that shows every corner you cut underneath it.
What you need, and roughly how much
Topsoil
The root zone
4 inches establishing a new lawn, at least
A lawn needs at least 4 inches of good soil to establish. If what is already there is that deep and reasonable, you are filling low points rather than importing a layer; if a builder scraped the site, you are importing the lot. Whatever comes in has to be weed free, because this is the one moment it gets tilled into the root zone rather than sitting on top of it.
One cubic yard covers about 81 square feet at 4 inches, so 300 square feet takes about 4 cubic yards (roughly 4 tons).
Good for: Building the root zone up to depth, and filling the low points the rough grade left behind. Not for: Anything that is not weed free. A weed seed tilled into a new seedbed is a weed you own for years.
Does the same job at this layer: Amended topsoil.
6 listed yards publish a price for this.
Compost
Blended through the top of the soil, never laid on it
1.5 inches blended into the soil before a new lawn (one to two inches)
Compost for a new lawn goes on at 1.5 inches, spread on the surface and then mixed in, which is shallower than a new planting bed takes. Mixed is the operative word: thorough blending is what keeps drainage uniform, and incomplete blending goes wrong later and cannot be undone.
One cubic yard covers about 216 square feet at 1.5 inches, so 300 square feet takes about 1.5 cubic yards (roughly 1.1 tons).
Good for: Ground that machinery has compacted or a builder has stripped, which is most new-build ground. Both mean poor drainage and harmed turf roots, and organic matter in the soil works against it. Not for: Laying it on top and hoping. Top-dressing an established lawn is a real practice; before a new one, it goes into the soil.
Does the same job at this layer: Manure compost.
4 listed yards publish a price for this.
Sod
The lawn itself, if you are not sowing seed
Sod is a live product cut when it is ordered, so price and what is available this week are the yard's answer to give and this goes through a quote rather than a checkout. It is sold by the pallet and the piece sizes differ from farm to farm, which is why the calculator hands you an area and the yard turns that into a count. However the lawn arrives, it goes onto the soil surface and gets pressed down to make contact with it.
89 listed yards carry sod. Price and what they have today are theirs to answer, so this goes through a quote rather than a checkout.
What else you will need
- A rototiller, hired. This is a depth-of-soil job over a whole lawn and a garden fork will not do it.
- A landscape rake for the finish grade. It is the last chance to take a hollow out.
- Grass seed or a sod order, and a straw or seed cover if you are sowing. Not sold here.
- A sprinkler and a timer, because the weeks after are watering weeks and a missed day undoes them.
How to do it
- Get the rough grade in first and give it time to settle, sloping away from the house, the drive and the paths.
- Bring the soil up to 4 inches where it falls short, using weed-free material.
- Spread compost 1.5 inches deep over the surface, ready to go in rather than to stay there.
- Till the topsoil, the compost and any fertiliser through the top of the ground together, on a day the soil crumbles rather than balls, and stop before you have destroyed the structure you came to build.
- Hand rake to the finish grade immediately before you sow or lay. This is the last opportunity to set the final level.
- Sow the seed, or lay the sod onto the surface and press it down so it makes contact with the soil.
- Water so the top of the soil never dries out, daily at first and more often than that in wind and sun.
Common mistakes
Seeding onto a grade that has not settled
Do the rough grading well in advance so the settling happens before the lawn does, and slope the ground away from the house, the drive and the paths. A hollow that appears afterwards is a hollow you live with.
Stacking good soil on compacted ground
A layer of bought soil sitting on a pan does not drain into it. Both sources treat topsoil and compost as things to blend into what is already there, to a stated depth, rather than as layers to stack on top of it.
Tilling wet soil, or tilling it to death
The test: too wet if a handful squeezed into a ball keeps its shape, ready when the ball crumbles. Tilling wet degrades soil structure, and over-tilling destroys it just as surely.
Letting the seedbed dry out
The top of the ground has to stay continuously moist right through germination, which usually means watering every day and sometimes more often than that on a windy, sunny one. This is where most new lawns are actually lost.
Doing it at the wrong end of the year
For cool-season grass the best window is late summer: warm soil to germinate in, cool nights to grow in, and almost no weed seed coming up to compete.
Work out how much
Add your area. The depth is already filled in.
Yards near you that carry it
584 listed yards carry soil; 288 listed yards carry compost; 89 listed yards carry sod. Set your area and the nearest come first, by distance and never by price. Every yard, by state · Topsoil prices · Compost prices