Is Topsoil Good for a Garden?

Topsoil improves garden production.

The right soil is the key to successful gardening. Improve your garden's bounty by adding topsoil, which is created by mixing different materials and adding the product to the soil at your site. The topsoil needs to be combined well with the sub-soil. There is no legal standard for topsoil, so it can be a combination of sand, clay, sawdust, manures and decayed plant material.

Components of Good Topsoil

The three main chemical and physical properties that influence topsoil quality in soils are pH, texture and organic matter content, according to Manjula Nathan, a University of Missouri Extension soil specialist. Within this mix, a good topsoil should be well-draining and loose to support growing plants, vegetables or grass. To achieve this characteristic, make sure to thoroughly combine the topsoil with the native soil so water will penetrate the soil and deeply water the plants.

Soil pH

The correct topsoil for your garden is determined by what's planted in the site. The soil's pH refers to its acidity or alkalinity. If the pH value of your soil is below 7.0, it is acidic; if it's above 7.0, it's alkaline. Most plants and vegetables thrive in soil that is maintained between 5.5 and 7.5. However, acid-loving plants such as azaleas, blueberries, conifers, ferns and hydrangea prefer pH below 5.5.

Good Texture and Organic Matter

A good mix of soil texture for the garden's topsoil is loam and silt loam, which is a mixture of sand, clay and decaying organic materials. These materials allow water and nutrients to penetrate the soil and at the same time allow the soil to retain moisture and nutrients. Organic matter helps keep soil loose and adds nutrients that help plants flourish. The ideal organic content is from 1 to 5 percent or more.

Buying Topsoil

Before you buy topsoil, ask the company what its mix consists of. Take a look at what they're selling. Pick up the soil and let it run through your hands; it should be dark and loose and smell like the forest. Plan to buy up to 6 inches of topsoil for new gardens and 9 inches for new lawns. One cubic yard of topsoil will cover about 35 to 50 square feet of garden or lawn at these depths.

References

• Press of Atlantic City: Arts & Entertainment; Gardens Really Dig a Good Topsoil's Nutritional Benefits; Mona Bawgus; January 2010
• PMN International: Applied Turfgrass Science; Good Topsoil Can Be Key in Renovating Lawns; Manjula Nathan; October 2009
• Oregon State University: Extension Service Garden Hints; Test Topsoil Before You Buy It: