Healthy Soil, Healthy Garden

Healthy Soil, Healthy Garden

The key to a successful garden is cultivating healthy soil. Soil is made up of minerals (clay, sand, silt) built up through natural geographic processes over long stretches of time, organic matter both living and dead, air and water. Soil should be teeming with life such as insects, bacteria and fungi that transform organic matter into nutrients for plants. Healthy soil is an essential part of a healthy ecosystem. Gardeners, taking their cues from natural processes, can restore degraded soils and foster natural processes for beautiful and productive gardens. Here are key strategies to building healthy soil:

Know your soil type and texture – Determine your soil’s mineral composition – clay, silt, and sand – to understand how it might hold water and what plants are best suited. Techniques such as touch and jar test help identify your soil types. Soil that is hard to penetrate, bare, shows signs of erosion, or does not quickly absorb rain are signs of compaction.

Test your soil – A standard soil test, which can be done through the Virginia Cooperative Extension, will shed light on soil nutrients, pH, and organic content. Any soil amendments should always be based on soil test results. Separate tests are required for different areas and uses in your yard – wet, dry, sun, shade, lawn, vegetable garden, ornamentals, etc.

Right plant, right place – Rather than adjust the soil to meet pH, soil type, or nutrient requirements of a specific plant, you should select plants suited to your soil conditions. Native plants are particularly suited to the variety of soil conditions found in Virginia. Turf grass species, on the other hand, generally prefer a higher pH than is typical and, lacking deep roots, do little to improve soil structure.

Cultivate living mulch – Having dense, layered plantings will promote soil health as the roots break up soil, and plant debris, including fallen leaves from trees, adds in organic matter to feed the microbiome in the soil. For vegetable gardens, you can plant a cover crop in September or early October, cutting it back a few weeks before plantings in the Spring for mulch—no need to till it into the soil.

Cover any bare soil – Adding a few inches of mulch such as leaf mulch or shredded wood to cover any bare spots in the soil will help retain soil moisture, add nutrients, prevent erosion, and suppress weeds.

Avoid disturbing the soil – Tilling and turning the soil disrupts microbial life and encourages weed growth. With the exception of badly degraded and compacted soil, which can benefit from working organic matter into the soil, the insect and microbial life in the soil takes care of decomposing and incorporating plant litter and mulch into the soil.

Don’t work wet soil – While not always possible, it’s best to let soil dry out some after rain before working in it or cutting the lawn to prevent soil compaction.

Limit use of fertilizers and pesticides -- A soil test should always be done before applying any fertilizers or other soil amendments, and pesticide use should be based on a diagnosis of disease or insect infestation. You should opt for organic products and carefully follow the directions for application. Synthetic fertilizers and pesticides interfere with the natural processes within the soil. As you build healthy soil your plants will be better able to defend against disease and pests.

For questions and advice contact the Extension Master Gardeners Help desk at mgarlalex@gmail.com, by phone (703) 228-6414, or drop in Monday-Friday, 9 a.m.- 12:00 p.m.

Resources

MGNV Virtual Classroom, Build Healthy Soil and Manage Water in Your Yard

MGNV Fact Sheet, Building Your Soil

MGNV, Soil Tests

Virginia Cooperative Extension, Building Healthy Soil

Virginia Cooperative Extension, Soil Sampling for the Home Gardener

Virginia Cooperative Extension, Explanation of Soil Tests