Gravel, Stone and Garden Soil Delivery in Spokane, WA

Gravelly, ashy ground

The USDA soil survey maps the ZIP's center point as Urban land-Opportunity, disturbed complex, 0 to 3 percent slopes. Paved or built-over ground makes up 60 percent of that map unit. The word disturbed in the name means the native soil has been dug, moved and mixed during construction.^[1]

The Opportunity series makes up 35 percent of the map unit, and its top mineral layer is a very gravelly ashy loam. Ashy loam has volcanic ash mixed into it, which makes it light and fluffy when dry. The gravel content means a shovel will hit plenty of stones, and some may need a pry bar to remove.^[1]

The survey rates that soil as well drained and places it in hydrologic soil group C, where water soaks in slowly. Water that gets past the surface moves on through the gravelly layers, but a hard rain or a fast snowmelt can run off before it soaks in.^[1]

Shrink-swell in the top 100 cm is low, at 1.5 percent. Ground with that rating barely moves between wet and dry, which is good news for pavers and stone patios. The bigger risk on ashy soil is that it can be soft and compress under load, so compaction before building matters.^[1]

The ground at the center point stands 1,880 feet above sea level.^[2]

Before you build on this soil, dig a test hole to see how deep the fluffy ashy layer runs and where the firmer gravel starts. On a disturbed lot the answer can change from one corner to the next. Any material that squishes or puffs up when you step on it should come out and be replaced with compacted Road Base.^[1]

Dry summers, snowy winters

The NOAA normals station at Spokane Intl AP, WA, about 5 miles away, averages 16.4 inches of precipitation a year. That is a fairly dry total, and summers can go weeks without rain. Dust from loose fines becomes a nuisance on unpaved surfaces in dry spells, so a well compacted surface with angular stone stays cleaner.^[3]

The airport station averages 45.4 inches of snow a year and logs 132 days when the low reaches 32 F or colder. Repeated freezing and thawing works water into any gap in a stone surface. Bases that drain freely ride out that cycle with little movement.^[3]

The median last spring freeze at Spokane Intl AP comes on April 26. The median first fall freeze arrives on October 12. Building and planting projects fit into the warm months between those dates.^[3]

Spring snowmelt can send a lot of water across frozen or slow-draining ground at once. Grade surfaces away from buildings, and give melt a path off a drive into a planted area or a stone swale.^[1],[3]

Dry, gravelly ground also means dust in late summer. Stone Dust Screenings and Decomposed Granite compact into a tight surface that keeps dust down better than loose soil, and a light watering before compaction helps them bind.^[1],[3]

A base on very gravelly soil

Gravelly ground gives a head start on a drive or patio, since the native soil already drains. Strip the topsoil and any ashy, fluffy material near the surface, then compact the gravelly layer underneath. Fill any soft spots with Road Base and compact them before moving on.^[1]

The state transportation department names its base stone Crushed Surfacing Base Course, under Section 9-03.9(3) of the Standard Specifications for Road, Bridge, and Municipal Construction M 41-10 (2027).^[4]

For a home drive, lay Road Base or 1-1/2" Crushed Gravel in compacted lifts. Clean, well graded crushed stone drains and resists frost heave. Top it with 3/4" Crushed Stone or Driveway Gravel and crown the surface so melt and rain run off to the edges.^[3]

Plowing a gravel drive takes some care. Set the plow shoes or snowblower skids a little high so they skim the snow instead of scraping stone. Edging along the sides keeps gravel out of the lawn, and a spring raking puts stray stone back where it belongs.^[3]

On disturbed ground, buried rubble or old foundations can show up in a dig. Firm, well packed rubble can stay as part of the base, but pull out loose pieces and fill the voids with Crushed Concrete or Road Base so the surface settles evenly.^[1]

Pea Gravel or crushed stone for paths

For a garden path, the choice comes down to Pea Gravel against an angular stone like 3/8" Crushed Stone or Walkway Gravel. Pea Gravel is round and smooth, comfortable underfoot and good-looking in a sitting area. It stays loose, so it needs firm edging and a base to keep it from wandering.^[1]

Angular stone packs into a firmer surface that is easier to shovel and holds its shape under snow and foot traffic. For paths you need to clear in winter, Walkway Gravel or Stone Dust Screenings make the better choice. Save Pea Gravel for patios and play areas that see less winter use.^[3]

Either kind of stone drains well over this gravelly soil, so puddles are rarely a problem on a path built on firm ground. A layer of landscape fabric under the stone slows weeds that would otherwise sprout through.^[1]

Beds for a short growing season

Very gravelly ashy loam drains fast and dries out quickly, which is hard on new plants. Raised beds filled with Garden Soil give roots a deeper, richer layer to grow in. For in-ground beds, rake out the larger stones and mix in Compost to help the soil hold moisture.^[1]

With a short frost-free stretch from late April to mid October, early planting matters. Raised beds warm sooner in spring, which buys a little extra time at each end of the season.^[3]

Mulch holds the moisture these soils lose fast. Spread Brown Shredded Mulch, Black Shredded Mulch or Wood Chips around trees and shrubs after the soil warms, and keep it a few inches from trunks. Topsoil works for leveling a lawn area before seeding.^[3]

Fall planting of trees and shrubs works well here, as long as it happens a few weeks before the median first freeze in mid October so roots can settle. Water new plantings deeply, since the gravelly soil sheds moisture quickly, and add mulch once the ground cools.^[1],[3]

Housing in 99201 next to the city figures

By the Census count, ZIP 99201 holds 9,164 housing units. Detached single-family houses make up 26 percent of them.^[5]

The median build year in the ZIP falls in the 1939 or earlier bucket. Owners occupy 30 percent of the occupied homes.^[5]

Spokane as a whole counts 102,834 housing units. Detached houses account for 64 percent of the citywide stock. The median Spokane home was built in 1961.^[5]