Gravel, Rock, Soil and Mulch Delivery in Olathe, KS

Swelling clay over shallow bedrock

The USDA survey maps Oska-Martin silty clay loams, 4 to 8 percent slopes, at the center point of ZIP 66061, with the Oska series making up half the map unit at 50 percent. The top mineral layer is silty clay loam, sticky and heavy when wet and hard when dry. The shrink-swell rating for the top 100 cm is very high, at 9.4 percent. That much swelling and shrinking can lift a patio slab, tilt pavers and open cracks in a dry summer.^[1]

The survey rates the soil well drained, but it sits in hydrologic group D, the group with very slow infiltration and high runoff. A restrictive layer of lithic bedrock lies at about 34 inches. Hard rock that close to the surface limits how deep a post hole or trench can go without a breaker bar, and it gives water soaking down through the clay a hard floor to spread across. Rain that cannot soak in runs off fast on slopes of 4 to 8 percent.^[1]

Shale and limestone in the bedrock

The USGS state geologic map shows the Lansing Group at the center point, a Pennsylvanian unit of shale, limestone and sandstone. Limestone beds in units like this are a common source of crushed stone in the region, so gray, angular products such as 3/4" Crushed Stone and #57 Crushed Stone are close cousins of the rock below. The shale layers break down into the clay that makes the soil above so sticky.^[2]

The ground at the center point rises 1,000 feet above sea level. That is one reading for one mapped spot. For a project, the slope of the lot and the way water moves across it after a storm matter far more, and both are easy to see with a walk around the yard during a hard rain.^[3]

Shallow rock also changes how you plan anything that needs depth. A deep trench for a French drain may end on bedrock before you reach the planned depth, and a tree planted in a hole cut into rock can sit in a bowl of water after rain. Keep drains shallow and wide where rock is close, and give new trees a broad, shallow planting area filled with Garden Soil rather than a deep pit.^[1]

Freezing nights and spring storms

The NOAA normals station at Olathe Johnson Co AP, KS, about 4 miles away, averages 37.5 inches of precipitation a year. Spring and early summer storms can drop a lot of water fast. On slow-draining clay, that water pools in flat spots and runs off slopes, carrying loose mulch and soil with it unless beds and paths are built with drainage in mind.^[4]

The station counts 110 days a year when the low reaches 32 F or colder. Its median last spring freeze is April 13 and its median first fall freeze is October 24. Clay that holds water through a cold snap can heave as it freezes and settle as it thaws, so any stone surface here needs a base that drains and a surface that sheds water.^[4]

A patio that stays level on clay

Patios and paver walks are some of the most common projects on suburban lots here, and swelling clay is their main enemy. Dig out the topsoil and a few inches of clay below, keeping the bottom of the dig sloped away from the house. Lay a woven geotextile so the clay cannot squeeze up into the stone. Then build a base of Road Base or Crushed Concrete in thin lifts, compacting each one hard with a plate compactor.^[1]

A thicker, well-compacted base spreads the push of swelling clay across the whole patio instead of letting it lift one corner. Screed a thin bed of Concrete Sand over the base and set the pavers, then sweep Stone Dust Screenings or sand into the joints. Give the patio a slight fall away from the foundation, and run a Drain Rock trench along its low edge so runoff from slow-draining group D ground has a path out.^[1]

For a driveway on the same ground, the recipe is similar but heavier. Strip the topsoil, lay a woven fabric and build a base of Road Base or 1-1/2" Crushed Gravel, compacted in lifts. Finish with Driveway Gravel or 3/4" Crushed Stone, which lock together under tires. A crown down the middle keeps rain moving to the edges, where a Drain Rock trench can carry it away from the clay below.^[1]

Lawns, beds and foundation edges

Heavy clay makes for slow-draining beds and compacted lawns. Raised beds filled with Garden Soil, or a blend of Topsoil and Compost, give roots loose, airy ground to grow in. When you top-dress a lawn, spread a thin layer of Compost or Topsoil after core aeration so it settles into the holes. Plant tender annuals after the April 13 median last freeze, and finish beds with Brown Shredded Mulch to keep the clay from crusting.^[1],[4]

Along foundations, keep the soil sloping away from the walls. A band of River Rock or #57 Crushed Stone over fabric next to the house keeps roof drip from soaking the clay right at the foundation, where repeated swelling and shrinking does the most harm. Extend downspouts so they empty onto a splash pad of River Rock well out from the walls.^[1],[4]

Play areas and side yards on clay can turn muddy fast. Playground Sand under a swing set gives a soft landing, but on clay it needs a layer of Drain Rock or #57 Crushed Stone below so rain can drain out of the sand instead of turning it into a pond. A side yard that stays wet can be covered in Pea Gravel or 3/8" Crushed Stone over fabric for a clean, dry path to the back gate.^[1]

Homes in ZIP 66061

The Census counts 25,329 housing units in ZIP 66061. Olathe as a whole has 54,594. Detached single-family houses make up 72 percent of homes in the ZIP, the same share as across the city. The median year built is 1994 for both the ZIP and the city. Owners occupy 78 percent of the occupied homes in the ZIP, so many projects here are owner-led yard upgrades: new patios, walkways, beds and edging.^[5]

Many homes in the ZIP are now old enough that their first round of landscaping is wearing out. Mulch beds have thinned, edging has heaved and original walks have settled. Fresh Black Shredded Mulch, a rebuilt paver walk on a proper base and a few yards of Topsoil for low spots in the lawn can make a big difference in a single weekend.^[5]