Landscape Consultants HQ   LANDSCAPE CONSULTANTS HQ

Join Landscape Consultants HQ for our newsletter with professional landscaping advice. You can opt out at any time.

Quality Soil for Quality Landscapes

compost, soil additive, organic matter

What should you add to prep your site for a beautiful, ornamental landscape? The easiest way to determine what to add to the soil before planting is to do a soil test. Testing is usually provided at the local government’s Ag-extension office. It is very cost-effective and very specific. It can save you from spending money on the wrong amendments or losing money on poorly-performing plants. The quality of the installed landscape is absolutely dependent on the test results.

Soil is soil, right? Maybe not. If you blindly dump an excess of certain nutrients on your site, you run the risk of causing a toxic chemical balance in the soil. You might apply nutrients in a way that could cause leaching into nearby streams, multiplying the damage you could be trying to mitigate by planting. Just get the soil test, okay?!  A void of the proper nutrients can result in plants that look nothing like the catalog pictures.

I know one thing. You will probably never get a soil test. I know another thing. Most professional contractors bound by the specifications to complete a soil test will never do this, either. It’s an extra two trips to the extension office for starters. A soil test is such a small concern, most field inspection engineers won’t enforce the requirement. The hesitancy enforce may be related to difficulty in interpreting the results. The results show chemical nutrient deficiencies, and most people don’t know a chemical element table from a biscuit recipe. Fertilizer bags aren’t much help, either. To calculate recommended rates, algebraic math is involved. As much as we all loved high-school algebra, inspectors may be the reluctant to study the new tasks suggested by the test and then check the contractor on compliance. A soil test is easy, but acting on the results is sometimes hard to do.

There are some things you can do to improve your soil without causing any harm. You never need a soil test before adding them to site. Tilling in or top-dressing the soil with quality, well-composted, weed and toxic-chemical-free organic matter will always improve the situation for your plants. It should be screened to keep the particles small and to keep any further decomposition from leaving large air pockets under the ground. There are a lot of unhealthy things that can be mixed with a little brown dirt to make them look benign. Add specifications in the contract for organic matter. Be picky about your source if you are the landscape contractor.

Add at least a sprinkling of organic matter to the soil. It can be expensive to add a preferred one or two-inch layer, but that may not be in your budget. The more you add, the more alive the dirt becomes, but good organic matter is expensive. 

soil additive, grit, granite fines

For seasonal beds and perennials, grit can really boost the growing potential of your soil. They provide aeration and good drainage. The right sized rock fines are too expensive to incorporate on a site-wide scale, so save them for the jewels of the garden—the flower beds.

Adding big rocks won’t do. You need to be able to use a mechanical tiller on the final soil mix, and big rocks will lock in the tines. Using rock dust will turn the soil to concrete. Sand might do the same thing. If you use sand, make sure it is very coarsely textured. Keep the grit fairly small, as shown in the picture above. It’s perfect. One to two inches, tilled into a berm of soil will turn your flower bed into a showstopper.

Soil Amendments