3/8" Natural Pea Gravel in Maryland: Rounded Stone for Places People Walk

Pea gravel jobs get planned in February and built in May, and the gap between those two months is where most of them go wrong. Spreading rounded stone is not the part that needs weather: the base under it is, and a base compacted on ground still giving up winter water will dish by August. The working season for the layer beneath runs from the point the ground dries in spring to the first hard freeze, and it is shortest in Garrett County and longest on the Shore. Order the stone for the back end of that window and the path will still be flat in five years.

Size: approximately 3/8 inch. Type: small, smooth, naturally rounded stones. Color: tans, creams, grays, browns and occasional reds, which comes from the stone itself rather than from a dye. Approximate weight, from this site's own published figures, about 2,800 lb per cubic yard, or 1.40 tons per cubic yard.

The garden path, the fire pit surround and the space under a deck

This is a finish material, bought for how it looks and how it feels rather than for what it carries. Four jobs account for most of what leaves the yard.

• Garden paths and back-door walks, where a soft, informal surface suits the route better than pavers.
• A seating area or fire pit surround, where the stone is walked on barefoot in summer.
• Play areas, where rounded stone has no cutting edges, drains after rain and does not break down the way wood mulch does.
• Drainage details at downspouts, along foundations and in swales, and ground cover where turf has given up.

Rounded stone on Piedmont clay and on Shore sand: two different results

The same load behaves differently depending on what it is spread over.

• Central Piedmont: silt loam and clay loam over crystalline rock, holding water and going soft when saturated. Pea gravel spread straight on clay works down into it over a couple of wet seasons until half the load is buried. It needs a compacted base under it, and it needs somewhere for the water to go.
• Eastern Shore and the lower Western Shore: sandy, well drained soil on higher ground, flat and slow to drain on low ground. Drainage is rarely the problem here; containment is, because loose rounded stone on sandy ground migrates easily.
• Western Maryland: 36 inch frost in the Garrett and Allegany codes, heavy snow, and a long freeze-thaw cycle. A shoveled path in rounded stone loses material to the snow bank every winter, which is worth knowing before a front walk is built in it.
• Within 1,000 feet of tidal water, Critical Area rules limit lot coverage and gravel and stone surfaces count toward it. A large pea gravel area is worth checking before it goes in.

Fabric, edging and the two inch rule when you spread it

Three install details do almost all the work.

Depth: two inches over a prepared base for a path or patio, three at most. Rounded stone rolls, and a deep layer rolls more, so a path that feels loose and tiring underfoot is almost always one that was laid too deep rather than one laid in the wrong stone.

Edging: not optional. Pea gravel will not hold its own line, and every walk across an unedged area sends a handful onto the lawn or the pavement. Steel, aluminum, timber or a soldier course of pavers all work, set proud enough to contain the depth you are laying.

Fabric: useful under a decorative bed or an area under a deck, where the job is keeping weeds down and keeping the stone out of the soil. Less useful in a drainage detail, where the base and the fall are doing the real work.

Pea gravel against walkway gravel and river rock

The trade is between comfort and stability. Crushed stone locks and stays where it is put; rounded stone never quite does, and that is exactly why it is pleasant to stand on.

Yardage for a wall backfill, a pond edge and a construction entrance

Square feet times depth in feet gives cubic feet; divide by 27 for cubic yards; multiply by 1.40 for tons. All three are worked examples rather than real projects.

• Retaining wall backfill, a 24 foot wall with a 12 inch wide drainage column 30 inches tall behind it: 1 x 2.5 = 2.5 cubic feet per foot of wall. 24 x 2.5 = 60 cubic feet, divided by 27 = 2.22 cubic yards, about 3.1 tons. Clean rounded stone drains well here, though #57 Stone is the more usual pick because the larger voids carry more water and the angular pieces settle less behind the wall.
• A garden pond edge, a 3 foot band around a pond measuring 12 by 16 feet: the outer rectangle is 18 x 22 = 396 square feet, less the pond at 12 x 16 = 192, leaving 204 square feet. At 3 inches, 204 x 0.25 = 51 cubic feet, divided by 27 = 1.89 cubic yards, about 2.6 tons. That works for an ornamental pond. A tidal shoreline is a different problem entirely, where wave action and storm tides call for RipRap sized to the exposure.
• A construction entrance, 50 feet by 12 feet at 6 inches: 600 square feet x 0.5 = 300 cubic feet, divided by 27 = 11.1 cubic yards. Pea gravel is wrong here: an entrance needs coarse angular stone to shake mud off tires. As #4 Crushed Stone at about 1.45 tons per cubic yard, that volume is roughly 16.1 tons.

For a curved path or an irregular bed, split the shape into rectangles and take the total through the pea gravel calculator.

Measure the area, settle the depth at two inches, get the edging ordered before the stone arrives, then choose an amount and a delivery date on this page. For a job that mixes a path, a bed and a splash area, email the measurements through contact and get the split checked first.