Evaluate soil for optimal garden output
Once a site has been selected for your vegetable garden, attention must be paid to the soil. Healthy soil optimizes both plant growth and vegetable yield through its structural and biological processes that occur at the root level.
Soil provides mechanical support for roots and allows roots to absorb and retain water. Carbon dioxide and oxygen exchange occurs in the roots, and soil composition promotes this process.
Learn about your soil by excavating a shovel-full of soil from several areas within the vegetable garden site.
While digging the soil, examine its color, texture and moisture. You may notice “layers” or horizons within the soil.
Penn State Extension recognizes these soil horizons as A (topsoil), B (subsoil), C (rock and minerals) and R (bedrock). The number and depth of these horizons vary among different soils.
Vegetable gardens are planted into the topsoil and subsoil layers.
Evaluate the soil's texture and moisture. Texture is the distribution of particle sizes within the soil; sand is the largest particle, silt is smaller than sand, and clay is the smallest particle.
Feel the soil by rubbing it between your fingers. Soil that is sandy has a gritty feel, while clay soil feels sticky.
Soil texture is linked to moisture retention. Water from rainfall and watering clings to the soil particle surfaces; with too much water that cannot drain away, less air is available to the plant roots. Such poorly-drained soil does not support plant growth.
Feel the moisture in the soil and note if the soil is dusty, damp or soggy. One visual indicator of soil with poor drainage is its color; soil with gray, yellow, orange and dark brown discolorations (mottles) should be avoided for garden usage.
Because soil is so important to a successful garden, invest in testing your soil. Soil testing may be performed in the fall or early spring. Test when the soil is relatively dry since soil must be dried to mix for sampling and to save postage. Test soil to allow a month or so to get results and implement any recommendations from the laboratory before time to plant.
Begin by obtaining a soil test kit. Penn State Extension soil test kits with directions for sampling, use, and mailing are available from the County Extension Office and local lawn and garden retailers. Go to https://agsci.psu.edu/aasl/soil-testing/fertility for mailing instructions and test costs in the event the Extension office is closed.The objective of soil testing is to measure the levels of nutrients available to plants. Based on the test results, recommendations for soil amending are reported.To obtain your soil sample, use a shovel or soil probe to obtain random samples from eight to 10 areas of the garden site.For vegetable gardens, dig or probe into the soil to a depth of 6 to 8 inches.Place the samples on a surface to dry, then blend the soil very well to assure an even mixture. Break down any lumps and discard stones, roots and non-soil material.Place at least one cup of this mixture into the sample bag from the soil test kit.Complete the form with your information, crop information, and how the results are to be returned to you. Keep your copy, then place the form and sample into the mailer and take to the post office to mail.Results should be received in two to three weeks.Soil testing is a necessary step for determining soil health prior to planting a vegetable garden.Visit Penn State Extension at the websites https://extension.psu.edu/soil-testing and https://extension.psu.edu/dont-guess-soil-test for more information on obtaining soil samples.If you have questions about soil sampling or home vegetable gardens, call the Master Gardener Garden Hotline at 724-287-4761, Ext. 7 or e-mail the Master Gardeners at: butlermg@psu.edu.Michael Pavelek II is a Butler County Master Gardener.
