Rock, Gravel and Soil Delivery in Goodyear, AZ

Gravelly loam, rock outcrop and a hardpan

The USDA soil survey maps Cherioni-Rock outcrop complex at the ZIP's center point. The Cherioni series covers 50 percent of the map unit, and rock outcrop, meaning bare stone at the surface, is the other part named in the unit. A yard on ground like this can switch from diggable soil to solid rock within a few steps.^[1]

The top mineral layer of the Cherioni soil is very gravelly loam, a mix of fine earth packed with pebbles and angular stone. The survey records a duripan at about 6 inches. A duripan is a layer cemented hard by silica, and it behaves like a buried slab: shovels bounce off it, roots cannot pass, and water stops on top of it.^[1]

The survey rates the soil well drained, yet places it in hydrologic group D, very slow infiltration with high runoff. The two ratings fit the same picture. The thin gravelly layer drains freely, but it fills fast because the hardpan sits so close, and the rest of a storm runs off across the surface. Shrink-swell is low, at 1.5 percent, so the soil itself barely moves as it wets and dries.^[1]

Very old rock below the desert floor

The geologic map places Early Proterozoic metamorphic rocks at the ZIP's center point. The unit is made of metasedimentary rock, metavolcanic rock and gneiss, and its age is Statherian. Rock of this kind formed when older layers were squeezed and heated deep underground, and it was later lifted and worn down until it reached the surface.^[2]

Metamorphic rock of this kind is hard and does not crumble easily, which is why it shows at the surface as outcrop rather than wearing away into soil. For a project, the lesson is simple. Plan stone work around the rock, not through it, and bring in the material a bed or a base needs rather than counting on what comes out of the hole.^[1],[2]

Rock outcrop also shapes the look of a yard. Many desert landscapes keep the exposed stone as a feature and build beds and paths around it. Where a yard needs more mass, Riprap and River Rock in mixed sizes can echo natural outcrop, and a ring of 3/4" Crushed Stone around each large stone ties it to the ground cover so the feature looks settled rather than dropped in place.^[1],[2]

Desert rain and rare frost at Litchfield Park

Weather averages come from the NOAA normals station at Litchfield Park, AZ, about 9 miles from the ZIP. It averages 8.2 inches of precipitation a year and 0.0 inches of snow. That is very little water, and it tends to fall hard and fast, which on high-runoff ground means sudden sheets of water across a yard followed by long dry spells.^[3]

The station records only 7 days a year with a low of 32 F or colder. A few frosty nights can nip tender plants, but they do no harm to gravel, rock or pavers.^[3]

At Litchfield Park the median last freeze date is January 7 and the median first freeze date is December 24. Covering frost-tender plants on the coldest nights around those dates is usually all the frost care a yard needs.^[3]

The ground at the center point stands 1,020 feet above sea level.^[4]

A rock yard that handles a downpour

Many desert yards use stone as the ground cover, and on high-runoff ground the layout matters as much as the stone. Grade the yard so storm water moves away from the house and toward a low spot or the street. Line that path with River Rock in mixed sizes to form a dry wash, and set larger Riprap at bends and outlets where the water moves fastest.^[1],[3]

Over the rest of the yard, lay fabric and spread a decorative cover. Decomposed Granite packs into a firm, tan surface for paths and patios. 3/8" Crushed Stone, Walkway Gravel and Pea Gravel make loose, easy walking areas. #57 Crushed Stone and 3/4" Crushed Stone give a coarser look around shrubs and boulders and let the brief rains soak in rather than splash. With only 8.2 inches of precipitation a year at the station, a stone cover keeps dust down and needs no watering.^[1],[3]

For a driveway, scrape off loose material down to firm gravelly soil or the hardpan. Fill low areas with Road Base in compacted lifts, which binds onto the hardpan well. Crushed Concrete and Asphalt Millings also pack firmly. Finish with 3/4" Crushed Stone or Driveway Gravel.^[1]

Depth matters for a stone cover. A thin layer lets fabric show through as it gets kicked around, while a layer a few inches deep stays even and shades the soil below. On ground where the duripan sits close, a stone cover over fabric also spares you from digging, since nothing needs to go deeper than the surface. Pick one main stone for most of the yard and use a second color or size only for borders and paths, which keeps the look calm and makes top-ups easier.^[1],[3]

Planting through a hardpan

With a duripan at about 6 inches, a tree or shrub planted in a normal hole sits in a buried bowl. Water fills the hole, cannot drain through the cemented layer, and drowns the roots after a deep soak. Break through the hardpan with a digging bar or an auger before planting, so water has a way down, and backfill with native soil mixed with Compost.^[1]

For vegetables and flowers, raised beds sidestep the hardpan entirely. Fill them with Garden Soil, or blend Topsoil with Compost, and cover the surface with Brown Shredded Mulch or Wood Chips to slow evaporation in the sun. Black Shredded Mulch and Red Mulch work too, though dark mulch heats up more in direct sun. Keep mulch a few inches back from stems, and water deeply and less often so roots grow down into the bed instead of staying near the surface.^[1],[3]

Watering habits matter as much as soil. Drip lines set under mulch or stone deliver water straight to roots and lose little to the sun. A thin layer of Compost worked into planting holes helps the soil hold that water longer. On the handful of frosty nights the station records each year, a light cloth over tender plants is usually enough protection.^[3]

Homes in ZIP 85338

The Census counts 25,516 housing units in ZIP 85338. Goodyear holds 42,159 units in all.^[5]

Detached single-family houses make up 87 percent of homes in ZIP 85338, a little above the Goodyear share of 84 percent.^[5]

The median home in ZIP 85338 was built in 2007, the same as the Goodyear median of 2007. Owners occupy 77 percent of the occupied homes in the ZIP. ZIP 85338 is in Maricopa County, and Gravel Valet also serves Avondale, Buckeye and Surprise.^[5]