Las Cruces Yard Guide
How Deep Should Landscape Rock Be?
Too thin and the weed barrier shows through in a season, goatheads pop up and wind scatters the gravel. Too thick and you’ve paid for rock nobody sees. Here’s the right depth for each rock size, how to figure tons, and what we see go wrong in Las Cruces yards.
Updated September 2026. Coverage figures from supplier coverage charts.
Quick answer
How deep should landscape rock be?
For most Las Cruces rock beds, lay 3/4-inch to 1-1/2-inch rock about 2 to 3 inches deep over weed barrier. Pea gravel and 3/8-inch rock can go 2 inches, larger 2- to 4-inch cobble needs 4 to 6 inches, and DG paths need about 3 inches, compacted.
A good rule of thumb: the layer should be at least twice as deep as the largest stone is wide, so every stone sits on other stones instead of on bare fabric or soil.
Depth at a glance
|
Rock size |
Depth |
|---|---|
|
1/4 to 3/8 in (pea gravel) |
2 in |
|
3/4 in |
2 to 3 in |
|
1 to 1-1/2 in |
3 in |
|
2 to 4 in cobble |
4 to 6 in |
|
DG path |
3 in, compacted |
Depth by rock type
How deep should each kind of landscape rock be?
Lay pea gravel and 3/8-inch rock 2 inches deep, 3/4-inch crushed rock 2 to 3 inches, 1- to 1-1/2-inch rock 3 inches, 2- to 4-inch river cobble 4 to 6 inches, and 4- to 8-inch cobble for swales and slopes about 6 inches deep.
|
Rock |
Typical use |
Depth |
Notes |
|---|---|---|---|
|
Pea gravel, 1/4 to 3/8 in |
Paths, pet areas, between pavers |
2 in |
Shifts underfoot; needs edging |
|
3/4 in crushed rock |
Most front-yard beds |
2 to 3 in |
Our most common choice |
|
1 to 1-1/2 in rock |
Beds, borders, around shrubs |
3 in |
Less likely to blow or kick around |
|
2 to 4 in river cobble |
Dry creeks, downspouts, borders |
4 to 6 in |
Needs depth to hide fabric |
|
4 to 8 in cobble |
Swales, slope armor |
6 in or more |
Often hand-set |
|
Boulders |
Accents, slope holding |
Buried about 1/3 |
Looks natural, won’t roll |
|
Decomposed granite |
Paths, patios |
3 in; 4 to 6 in for driveways |
Wet and compact in layers |
Mixing sizes? Go by the largest stone. And if you’re putting rock on a slope, add an inch: gravity and monsoon runoff thin it out over time.
How much to order
How many tons of landscape rock do you need?
Rock is sold by the ton. Multiply length by width to get square feet, then divide by how many square feet one ton covers at your depth. At 2 inches deep, a ton of most rock covers about 120 square feet, and deeper layers cover less.
|
Depth (rock up to 1-1/2 in) |
Coverage per ton |
|---|---|
|
1 in |
About 240 sq ft |
|
2 in |
About 120 sq ft |
|
3 in |
About 80 sq ft |
|
4 in |
About 60 sq ft |
|
6 in |
About 40 sq ft |
Coverage from Southwest Landscaping Materials’ coverage chart. Larger rock covers less: 2 to 4 inch rock is about 65 sq ft per ton, and 5 to 12 inch rock about 45 sq ft per ton. Order about 10 percent extra.
Example: front yard bed
A 20 by 15 foot bed is 300 sq ft. At 3 inches deep, 300 ÷ 80 = about 3.75 tons, so order 4 tons. At 2 inches, 300 ÷ 120 = 2.5 tons.
Example: dry creek bed
A 40 foot long, 3 foot wide creek bed is 120 sq ft. With 2 to 4 inch cobble at about 65 sq ft per ton, that’s about 2 tons, plus a few boulders.
Why it matters here
Why does rock depth matter in Las Cruces?
Thin rock lets light reach the soil, so goatheads and spurge sprout in the gaps. Small, thin gravel blows onto walks in spring wind, and monsoon storms wash thin rock off slopes. A full depth over fabric, with larger rock where water runs, prevents all three.
Goatheads and weeds
Thin rock lets light reach the soil. Goatheads and spurge sprout in the gaps. A full 2 to 3 inches over fabric, plus pre-emergent in late winter, keeps most of them out.
Spring wind
Small, thin gravel blows onto walks and patios. Slightly larger rock at full depth stays put.
Monsoon runoff
Heavy storms wash thin rock off slopes and away from downspouts. Use cobble where water runs, and go deeper there.
Heat around plants
Rock holds heat. Pull it back a few inches from trunks and stems, and don’t pile it deeper around plants than the rest of the bed.
Weed barrier showing
Fabric peeking through is almost always a depth problem. Top off with 1 inch of matching rock rather than laying new fabric.
Cost
Every extra inch adds about 25 to 50 percent more rock. Stick to the right depth for the size instead of piling it on.
Avoid these
What rock depth mistakes should you avoid?
Avoid laying one inch of rock over fabric, skipping edging so rock creeps into lawns and walks, piling rock above the slab or stucco weep screed, burying drip lines too deep under cobble, and spreading rock over low spots that turn into puddles in monsoon season.
What it costs installed
Installed rock with weed barrier in Las Cruces usually runs about $3 to $6 per square foot. Removing old rock first adds about $1.50 to $3 per square foot.
Free tool
Landscape rock calculator
Find how many tons and cubic yards of rock you need, and a typical installed cost in Las Cruces.
Your result
Tons, cubic yards and cost will show here.
Landscape rock depth FAQs
Want your rock done at the right depth?
We remove old rock, set the grade, lay weed barrier and install rock at the right depth for its size. Free, written estimate.
Las Cruces Landscaping Group
1921 Santa Ines Drive, Las Cruces, NM 88011
(575) 270-0676. Mon to Sat, 7 a.m. to 7 p.m.
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