Gravel, Soil and Landscape Rock Delivery in Pomona, CA

Built-over ground and the loam beside it

The USDA soil survey maps Urban land-Biscailuz-Pico complex, 0 to 2 percent slopes, at the ZIP's center point. Urban land, meaning ground already paved or built over, covers 45 percent of that map unit. The Biscailuz series makes up 30 percent, and the rest is mostly the Pico soil.^[1]

Where the native soil shows through, its top layer is loam, a balanced mix of sand, silt and clay that digs well and holds a moderate amount of water. Shrink-swell in the top 100 cm rates low, at 2.9 percent, so the ground does not heave much as seasons change. Built-over ground is a different matter, since old fill, buried concrete and compacted gravel turn up in a dig more often than loam does.^[1]

The survey rates the soil somewhat poorly drained and places it in hydrologic group B, moderate infiltration. Rain soaks into exposed loam at a fair pace, but water can linger lower in the profile. Paving around a lot also sends more runoff toward whatever open ground is left, so a bed beside a wide slab may collect more water than the soil rating alone suggests.^[1]

The mapped center point of ZIP 91766 reads 790 feet in elevation. On a lot with only a gentle grade, retaining walls are rarely needed, but every patio and walk still wants a small fall built in so irrigation runoff and winter rain do not pond against a wall.^[2]

Refreshing an old driveway

Many gravel drives and parking strips in an older area just need new life. Rake out the worn top, fill ruts with Road Base and compact them, then spread a fresh layer of 3/4" Crushed Stone or Driveway Gravel. If the old base is still firm, there is no need to dig it out.^[1]

When a drive has gone soft or sunk, dig to firm ground and rebuild it. Lay fabric over the compacted loam, place Road Base or Crushed Concrete in thin lifts, and finish with a top stone. On somewhat poorly drained soil, a slight crown and a Drain Rock trench at the low end keep water from softening the base after a wet winter.^[1]

Asphalt Millings are another option for a drive or a back lot. They pack down and bind as the sun warms them, giving a firm, dark surface that sheds water better than loose stone.^[1]

Dry summers and short winter cold

Weather normals come from the NOAA station at Pomona/Fairplex, CA, about 3 miles away. It averages 14.5 inches of precipitation a year and 0.0 inches of snowfall. Most rain falls in the cooler months, and summers run long and dry, so beds and lawns depend on irrigation for much of the year.^[3]

The station logs 3 days a year with a low of 32 F or colder. Its median last freeze date is January 8, and its median first freeze date is December 28. A cold night can still nip tender plants around the new year, but frost does not lift a gravel base.^[3]

Long dry stretches change how a gravel surface behaves. A compacted base made with Road Base can loosen at the top as its fines dry out and get kicked up by tires. A light watering before compaction, and a cap of clean stone afterward, keeps the base bound. Stone Dust Screenings under a walk behave the same way and set up firmer when they are dampened and tamped.^[3]

Lawn edges, beds and mulch

Loam is good garden soil to begin with. Mix Compost into the top layer to boost organic matter, or add Garden Soil when a new bed goes in over ground that was once paved. Where old fill or gravel sits under a planting area, dig it out and replace it with Topsoil so roots have room.^[1]

Cover beds with Brown Shredded Mulch, Black Shredded Mulch or Red Mulch to slow evaporation through the long dry season. Wood Chips suit play areas and paths under trees. Keep mulch a hand's width from trunks and stems so bark stays dry.^[3]

For a low-water yard, swap part of the lawn for Decomposed Granite paths and River Rock beds. Lay fabric under the rock to keep weeds down, and use 3/8" Crushed Stone for a path that is easy to walk on.^[3]

Decomposed Granite or Pea Gravel for a garden path

Most paths through a dry-climate garden use Decomposed Granite or Pea Gravel. Each one suits a different kind of walk. Decomposed Granite is made of fine, broken granite with grains of many sizes, and once it is wetted and tamped it packs into a firm, almost solid tread. Pea Gravel is a rounded stone of a single size that stays loose and crunches underfoot.^[3]

For a path that takes strollers, wheelbarrows or daily foot traffic, Decomposed Granite is the steadier choice. Its warm, sandy color sits well beside drought-tolerant planting, and a fresh top layer every few seasons brings back a worn tread without digging anything up. For a looser, informal path, a seating nook or a border along a bed, Pea Gravel drains instantly and never turns muddy. Over loam that holds moisture, set either one on fabric and a thin compacted base so the stone does not sink into the soil after winter rain.^[1]

Good edging makes either choice last longer. A steel, stone or paver edge set a little above the surface keeps Decomposed Granite from crumbling at the sides and stops Pea Gravel from spilling onto the lawn.^[1]

Homes in ZIP 91766

The Census counts 20,445 housing units in ZIP 91766. Detached single-family houses make up 62 percent of them, a little above the 59 percent share across Pomona. Owners live in 54 percent of the ZIP's occupied homes. The median home in the ZIP dates to 1974, and the city median is 1967. Pomona as a whole has 44,373 housing units.^[4]

For state highways, Caltrans specifies Class 2 Aggregate Base under Section 26-1.02B of its Standard Specifications (2026) as the stone layer under its pavements. A home driveway does not need to meet a state road book, though the same layered, compacted approach makes it last.^[5]

Patio projects come up often on detached lots, and so do rebuilt walks and fresh gravel beside a garage. Compact a base, screed a thin layer of Concrete Sand, and set pavers on top. Mason Sand works for the joints and for a smooth finish layer under flagstone. Run a plate compactor over the finished field once the joints are full, then sweep in a second pass of sand to top off any gaps that opened.^[4]