Gravel, Stone and Soil Delivery in Avondale, AZ

Flood plain soil over ancient granite

At the ZIP's center point, the USDA soil survey maps Torrifluvents. The name describes young soils laid down by floods on a desert flood plain, in thin layers of sand, silt and gravel. They form in a dry climate, so they hold little organic matter.^[1]

Layered flood soils change from one spot to the next. One part of a yard can be sandy and fast to drain, while a few steps away a silty layer holds water longer. Dig a couple of test holes before a big project to see what is there. The ground at the center point stands 1,050 feet above sea level.^[1],[2]

The geologic map shows Early Proterozoic granitic rocks at the same point, with an age of Statherian. The rocks in that unit include granite, granodiorite, tonalite, quartz diorite, diorite and gabbro. Granite of this kind weathers into the coarse grit known as Decomposed Granite, the same material many desert yards use for paths.^[3]

Eight inches of rain at Litchfield Park

The NOAA normals station at Litchfield Park, AZ, about 10 miles away, gives the weather averages used here. It records 8.2 inches of precipitation in an average year and 0.0 inches of snow. Dry ground is the rule, and dust is a bigger problem than mud for most of the year.^[4]

The gauge counts 7 days a year with a low of 32 F or colder. The median last spring freeze there is January 7, and the median first fall freeze is December 24. Those few cold nights matter for tender plants in a new bed, not for stone.^[4]

Desert storms can still drop a lot of rain in a short burst. Flood plain soil that has dried hard sheds that first rush of water before it soaks in. A gravel yard needs a slope away from the house and a path for runoff, such as a dry creek bed of River Rock.^[1],[4]

Decomposed Granite, rock cover and paths

Decomposed Granite is the classic desert surface. Spread in thin layers, wet down and rolled, it packs into a firm, tan floor for paths, patios and seating areas. It drains slowly through its fines, so give it a slight slope to shed water.^[3],[4]

For general rock cover in beds and front yards, 3/4" Crushed Stone and 3/8" Crushed Stone give a crisp, even look. River Rock brings a rounded, creek-bed look to the ground between shrubs. Lay fabric under rock cover to slow weeds and keep the stone from mixing with the soil.^[1]

Walkway Gravel and #89 Crushed Stone suit paths that get daily use. Each of them has angular faces that lock together under foot, and each stays flatter than Pea Gravel, which rolls and spreads.^[1]

Boulders give a rock yard shape. A few large stones set partway into the ground, with River Rock and smaller crushed stone around them, look more natural than a flat spread of one size. Place them where water might cut a channel, such as the end of a downspout, so they work as well as look good.^[4]

Rock cover holds heat in summer. A wide spread of stone next to a west wall can warm the area around it well into the evening, so many yards keep a few shade trees or a mulched bed near the house to soften it.^[4]

A drive on layered desert soil

Scrape off the loose top layer and wet the subgrade before compacting it. Dry, layered flood soil does not compact until it has some moisture in it. Dig out any soft, silty pocket and refill it with compacted Road Base.^[1]

Desert ground can hide a hard, crusted layer below the surface where minerals have built up over time. A shovel that suddenly stops in dry ground may have reached one. Break through it with a bar where a planting hole or a drain pit needs to go deeper, so water and roots can pass.^[1]

Spread Road Base in thin lifts, wetting and compacting each one. The stone dust in the mix binds into a hard layer as it dries in the sun. For a drive that carries an RV or a trailer, a lower course of 1-1/2" Crushed Gravel or Crushed Concrete adds strength.^[1]

Edges matter on a desert drive. Without a border, the stone at the sides thins out and the soil beside it breaks down into dust under tires. A steel edge, a row of set stone or a concrete curb holds the base and the top layer together, and it gives a clean line against rock cover or a bed.^[1]

Finish with a thin top of 3/4" Crushed Stone or Driveway Gravel. Crown the drive so a summer storm runs off to the sides. Asphalt Millings are another option. They pack hard in the heat and keep dust down on a drive with heavy use.^[4]

Planting in desert soil

Flood plain soil in a dry climate has little organic matter. Fill planting holes with Garden Soil, or mix Topsoil with Compost, so roots have a richer zone to grow into. Water deeply and less often so roots reach down.^[1]

Mulch holds moisture in a bed under strong sun. Wood Chips and Brown Shredded Mulch work well around shrubs and trees, though both break down and fade faster in desert heat. Rock cover can take over once plants are established.^[4]

Shade matters as much as water in a desert yard. A tree planted on the west side of a patio, with a ring of Wood Chips around it, cools the stone and the house wall by late afternoon. Keep rock cover out of that ring so the soil under the tree stays cooler and holds moisture longer.^[4]

Tender plants are safest set out after the median last spring freeze of January 7. A frost cloth on the few cold nights each winter protects young plants until they settle in.^[4]

Newer homes in ZIP 85323

The Census counts 14,975 housing units in ZIP 85323. Detached single-family houses make up 73 percent, and owners live in 59 percent of the occupied homes. The median home in the ZIP was built in 2004.^[5]

Avondale as a city has 31,547 housing units by the Census count. Across the city, 74 percent are detached houses, and the median build year is 2002. Many back yards on lots of that age were left as bare dirt, and finishing them with rock, a paver patio and a few beds is a common first project.^[5]