Don't Guess....Soil Test

​ Why Bother?

We borrowed the catchy phrase,” don’t guess...soil test,” from the Penn State extension.  Are you a 5-Step lawn applicator? Do you hire a lawn service to spray chemicals on your lawn?  You may be wasting your money and harming water systems. Plants are similar to people. Humans seek tests for cholesterol, blood pressure, and a variety of other health metrics which give guidelines on how to best feed and care for our bodies.  Similarly with plants, we need to test and ensure that we are giving them the proper food to thrive and withstand stresses like drought, pests and diseases. The healthier a plant, the quicker it can respond to stresses without chemical intervention.

Proper soil fertility is the foundation for plant health.  Whether you have grass, flowers, trees or a few shrubs, you will save money and our environment by conducting a soil test.  It provides you with exactly the nutrients required for your lawn and plants. A $9.00 investment in a Penn state soil test will inform you about organic matter, pH in the soil and ensure that you are applying the proper amounts and type of plant food.  Soil tests often reveal that adequate quantities of soil nutrients are present, thus preventing unnecessary or harmful fertilizer applications.

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Feed the soil, not the plant
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Fertilizers contain plant nutrients.  When we add fertilizers to our soil, the nutrients stick to organic matter particles--- almost like a sponge.  Organic matter holds onto the nutrients that plants use for growth. The correct ratio of organic matter will increase the soil’s ability to store the nutrients until your plants are ready to use them.  Soils that don’t have much organic matter can’t hold onto soil nutrients very well. When you apply fertilizers to these low-organic-matter soils, much of the fertilizer washes away when you water the soil.

Bottom Line
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Without proper organic matter, the lawn fertilizer companies and 5-step lawn products, or other fertilizers for flowers, trees and shrubs wash into our waterways and pollute our environment.

The best way to know how much organic matter or the appropriate amount of plant food you need is to conduct a soil test.

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4 Easy Steps
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Here's the procedure for using the Penn State soil testing service (Scott Guiser, Bucks County extension educator).

• ​Purchase a soil test mailing kit ($9.00) for each area you plan to sample. The "kit" consists of a pre-addressed envelope, instructions, and a soil sample bag. The kit price includes the testing fee. Each area (lawn, flower garden, vegetable garden, etc.) requires a different test kit. The kits are available from all Penn State Extension offices. You may also get soil sample submission forms from the Ag Analytical Service Laboratory, and send payment to the lab along with your soil sample.​

• Define the area to be tested. It may be a flowerbed, pasture, small orchard, or community athletic field. In any event, zigzag your way throughout the area and collect soil from 12 to 15 locations. Put sub samples all together into a clean container. The goal is to get a composite sample that represents the entire site. Paper lunch bags or a clean bucket will work well. Sample 3-4 inches deep for turf and pastures, and 6-10 inches deep for other plants. Avoid sampling odd spots on any site. Throw out stones, sod, and thatch.​​

• A garden trowel is a good tool for sampling in tilled or mulched soil, but a soil sampling probe or auger is faster, especially when sampling through existing sod. Regardless of the tool used, be sure to sample to the proper depth and get a representative sample by collecting at least 12 subsamples from the area. Mix the sub samples into one composite sample. Spread the sample on a clean newspaper and allow it to dry overnight. Do not heat the sample.

• Complete the questionnaire that comes with the soil test kit. The directions are self explanatory. Follow them carefully. Be sure to indicate what "crop" you are growing. Add the recommended amount of soil to the soil pouch. Take it to the post office to determine the appropriate postage and send it off using the pre-addressed envelope. Results will return from the Penn State lab in about 2 weeks. A copy of your results is made available to your county extension office as well. If you have questions about interpreting the results, contact your county extension educator.

Soil testing should always be a fundamental step of landscape design.  I’ve had clients seek my help when two pricey trees were planted in the same spot, and despite proper care, each died. In another case, a soil test of a lawn revealed that a back yard had an overabundance of fertilizer because of poor drainage; and a front yard on the same property showed very different results because of its slope.  Therefore, the treatment to improve each portion of the lawn was altered. In this instance, use of a traditional 5-step program would have resulted in washing chemicals and money down the drain, and into streams and rivers. ​

In preparation for the spring planting season, order a soil testing kit from your state’s extension office.  Take the guessing out of gardening.

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For more information on healthy soils visit the USDA website or PASA (Pennsylvania Sustainable Agriculture).