There is no such thing as perfect soil. All soil has some sort of problem structure, texture or chemistry.
Good soil is loose and crumbly because it has lots of air spaces, the National Garden Bureau says. Plant roots penetrate good soil deeply for extended drought resistance and stability.
Typically, however, soil in the home landscape is compacted, the air compressed from it by the weight of feet tromping across lawns and gardens. Construction, mechanical yard-care equipment and harsh weather do their own share of damage to soil.
To reduce compaction, regularly add humus–decayed organic material, such as compost–as a top-dressing to existing lawns. Spread organic mulch, such as leaves, shredded hardwood or wood chips, on bare soil in beds and under trees and shrubs year-round. Dig compost, peat moss or something similar into gardens when you can. All this helps improve aeration; it also invites earthworms to live there and naturally improve your soil.
It helps to know your soil. Most homeowners have one of three types of soil: dense sticky clay, thin gritty sand or powdery silt. Few of us have the nice loamy soil found in the woods, where plant debris, dead animals and other organic matter create a nice natural humus.
Clay soils, common in the Chicago area, are thick, with small particles and tiny air spaces. Clay particles stick together, causing water to fill up air spaces. Plant roots rot and suffocate from too much water and too little air. Add humus to clay soil to prevent the small particles from binding so tightly. Humus causes clay to collect into larger clumps, creating larger spaces that allow water to drain and air pockets to form.
Remember, soil can become sterile over time. Hot weather reduces humus content. Topsoil washes away if bare spots exist and micro-organisms become depleted.
Fertilizer provides nutrients to plants, but it’s not the long-term solution.
Most fertilizers contain the main ingredients: macronutrients such as nitrogen, phosphorus and potassium along with some sulfur, calcium and magnesium.
But many plant problems can be traced to a lack of micronutrients, says Dave Bankes, horticulture professor at Christopher Newport University in southeastern Virginia.
Micronutrients, often called trace elements, include iron, manganese, boron, copper, zinc, molybdenum and chlorine. They often are missing from commercial fertilizers.
