Soil Preparation & Grading

Grading is shaping the soil surface

When designing landscape improvements, we work in 3-dimensions. Shaping the ground, which we call grading, is our first step in any project.   Surface drainage, a critical feature of any successful landscape, is created through proper grading. When possible, equipment is used at this stage to shape and excavate.  When necessary, it is back to pick and shovel.

Definition of Grading

Soil Preparation

Good soil supports healthy, thriving plants. If you want to reduce yard maintenance (and most people tell us they do) good soil is the key. Plants thrive in good soil, helping to out-compete weeds. Good soil even makes weeds easier to pull out.

The majority of soils in our area have high clay content. Some plants tolerate this condition, but most prefer a lighter soil with pore spaces created by the addition of compost or other soil amendment. For these clay soils we typically rototill a few inches of amendments into the soil, before finish grading. Lawns and other shallow rooted plants benefit from this practice.

Many plants require additional soil improvement, to support deep rooting. Planting beds which are built up into mounds with as much as 12 inches of rich, fast draining soil can become a three-dimensional design element in the landscape.  Contouring the surface really adds interest, especially in flat yards.

Mulching

Mulch protects the soil from compaction, and moderates soil moisture and warmth.  Bark mulch is most common, with a 2” to 3” layer.  However, this practice, which started because it was a by-product of Oregon’s lumber industry, has become increasingly more expensive to sustain. 

Surface drainage, a critical feature of any successful landscape, is created through proper grading. Also, the three dimensional design of the ground can be a useful design tool, particularly when working with sloping landscapes.

What strange and expensive practices:  hauling in mulch in one truck, and lawn clippings out in another!  Those interested in “sustainable” practices learn to value the leaves, clippings, all organic material their yard produces, and put it to work as a form of mulch. Mulch alternatives include: 

• Stone Products, which have the advantage of not decomposing (this is also a disadvantage as soil benefits from the decomposition process)
• Wood Chips, like the ones arborists create with chipping up tree limbs and brush.  While less expensive, they are not very pretty
• Organic Products such as mint compost, aged sawdust, horse stall cleanings, etc.  These are used with knowledge of how you are building the soil over time.
• Ground cover plants, which spread and cover the soil, leaving less area to be mulch over time.  Many plants serve this function, as does lawn.  In the case of lawn, we actually have to mow the stuff down, and haul it off!