Kennewick Soil Delivery

My backyard has a lot of caliche or hardpan. Will adding soil on top actually help?

Caliche layers are a real issue in parts of the Kennewick area, particularly in older subdivisions and areas with minimal prior landscape development. Adding soil on top of an intact caliche layer creates a perched water table situation where irrigation water fills the added soil and has nowhere to drain, which can drown roots even in a desert climate. Before adding bulk soil over a hardpan, it helps to break through that layer at several points with a digging bar or post-hole digger to create drainage pathways. Once you have those channels, a quality added soil layer above works very effectively.

What depth of new soil should I bring in for a vegetable garden in Kennewick?

For vegetable gardening in Kennewick, aim for at least 8 to 12 inches of quality soil depth to give root systems adequate room in a friable, moisture-retentive growing medium. The hot, dry summers here stress plants enough above ground, and confining roots to a shallow or compacted layer adds unnecessary stress. If you are building a raised bed on top of existing silt loam, a 10 to 12 inch fill depth is ideal. If you are tilling new soil into an existing bed, 6 to 8 inches incorporated deeply gives a solid foundation.

Is there a best time of year to have soil delivered in Kennewick?

Spring is the most popular time for soil delivery in Kennewick, specifically in March and early April before the last frost window closes around April 5. At this point the ground is workable, temperatures are mild for physical labor, and you have time to let the new soil settle and begin developing biology before planting season hits full stride. Fall delivery after the October harvest is also smart for homeowners who want to prep beds for the following season, as the new soil has all winter to integrate and the cooler temperatures make spreading and raking far more comfortable.

How do I know how much soil to order for a raised bed project?

Measure the length, width, and intended depth of your raised bed in feet and multiply all three numbers together to get cubic feet. Then divide that number by 27 to convert to cubic yards, which is how bulk soil is sold. For example, a 4-foot by 8-foot bed filled to 12 inches deep requires about 1.2 cubic yards. It is always better to round up slightly when ordering for Kennewick projects since the soil will compact somewhat after the first several waterings.

Will the soil I order work for patching bare spots in my lawn?

Yes, a quality topsoil blend works well for lawn patch work in Kennewick, particularly for filling low spots or areas where the native silt loam has eroded or compacted beyond recovery. Spread the new soil to a depth of about 1 to 2 inches over the bare area, rake it level with the surrounding grade, and seed or sod immediately. In Kennewick's dry climate, keeping newly seeded areas consistently moist for the first two to three weeks is critical, so plan your patch work for a time when you can water daily.

Does the wind in the Tri-Cities area blow away fine soil or cause it to dry out too fast after delivery?

This is a genuine concern and something Kennewick homeowners deal with regularly. Fine, dry topsoil left in a pile or spread thin can blow significantly in the strong Columbia River corridor winds. If you cannot spread and work your soil within a day or two of delivery, lightly moisten the top of the pile to reduce wind erosion and if possible cover it with a tarp. Once incorporated into beds and topped with mulch, the soil is protected from wind drying and will retain usable moisture much more effectively.