Image of soil testingA soil test is a chemical analysis of your soil.  The basic test provides information on the plant available content of the major and minor nutrients in your soil as well as pH and cation exchange capacity.  Samples are analyzed for phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), and zinc (Zn) and fertilizer recommendations are made based on the plant grown and growing conditions.  

The process to collect a soil sample for testing is straight forward as outlined in the steps below.  For more detailed instructions, information, and link to a video, see the list of accompanying resources at the bottom of this page.

Image of items needed for soil test

Step1

Assemble your tools. All you need are a shovel/garden trowel or a soil probe (available for loan at your County Cooperative Extension office), a clean dry bucket, and clean, spill-proof bags for your samples. Your sample will be transferred to a soil test bag for analysis.  These bags are available from your Cooperative Extension office.  Collect about 2 cups of soil for each area that you sample.  


Step 2

Assess your landscape and identify the major areas you want to sample such as the lawn, flower beds, or vegetable garden.  Identify areas with plants requiring specific soil conditions such as blueberries, azaleas, and rhododendrons.  Also look for differnt micro-environments in your yard.  For example, you might want to collect separate samples from areas that are mostly sunny versus those in deep shade, or dry areas versus wet areas.   Do not sample compost areas, under the dripline of trees or near sidewalks and driveways.


Image demonstrating Step 3: Collection of a soil sampleStep 3

Work by area and collect samples from several random locations within that area, keeping the soil from each area separate. For lawns and untilled areas, insert your sampling instrument (soil probe or shovel/trowel) to a depth of about 4”.  If using a shovel or trowel, move the blade back about an inch and again insert it into the soil.  For an area that has been tilled or turned, such as a vegetable garden, you will want to sample to a depth of 6" to 8".  Remove turf and plant debris from the top of your sample and place in the bucket.


Step 4

Mix the soil in the bucket by breaking up large clods.  If the soil is wet and difficult to mix, allow it to air dry for a day or two. The goal is to be able to combine your soil sample so it is representative of your sample area.  Remove sticks, rocks, mulch, grass or organic debris.  Once well mixed, remove a portion of the sample and place it in a labeled sample container.  Again, you will need about 2 cups of soil to reach the "fill" line of the soil test bag.  Repeat the mixing step for each area sampled.  (Note that you may transport your samples in your container and transfer them to soil test bags at the Extension office). 


Image of soil test bag

Step 5

Label each soil test bag with your name and address and provide a unique 4-character name for each sample.  For example, if you collect two samples from your front yard (FY) you might choose FY01 and FY02.  Note where each sample was collected, plant type grown (grass, perennials, annuals, evergreens, trees or shrub) and growing conditions (shade or sun).  This information will be entered on the request form and is important to more closely match nutrient recommendations with plant needs.  


Deliver your soil samples to your county Cooperative Extension Office.  Cost varies by county but is generally less than $10 per sample.  For a limited time, Fayette County residents who submit samples for their home and garden may have their soil analyzed for free as part of the "No P On My Lawn!" program"*.  Just mention the program when you drop your samples at the Fayette County Extension office, 1140 Harry Sykes Way Lexington, KY 40504.

Resources:

Taking Soils Samples for Horticulture Crops

AGR-16: Taking Soil Test Samples

AGR-57: Soil Testing: What It Is and What It Does

Soil Testing and Fertilizers for Home Lawns (YouTube Video)

*The program is funded though the Lexington-Fayette Urban County Government Stormwater Incentive Grants Program.