Know Your Soil Type

An important part of successful home landscaping is to know what soil type you have. Test your soil to determine what vegetation will grow best in your soil conditions. Some plants thrive in soil with more acidity, and others prefer a little more alkalinity.

If you want to use plants for which the soil type is not ideal, you can change the soil conditions. It’s usually easier to make soil more alkaline than it is to make it more acid, although it’s best to make it a long-term project. Test your soil each year and make adjustments gradually. You can add lime, hardwood ash, bone meal, crushed marble, or crushed oyster shells to raise the soil pH (that is, increase alkalinity).

To lower the soil pH (make it more acid), you can use sulfur, sawdust, composted leaves, wood chips, cottonseed meal, leaf mold, or peat moss.

Additionally, whether the soil type is sandy, clay, or loam can make a difference in what plants thrive in a landscape. Soil is composed of particles of varying sizes that are classified into three major groups:

• Sand particles are the largest and tend to hold little water but allow good circulation of air.
• Clay particles are very small and tend to pack down so that water does not drain well and little or no air can penetrate.
• Silt particles are medium sized and have properties in between those of sand and clay.

A mixture of sand, silt, and clay in roughly the same amounts is called loam. Loam soil is ideal for most garden plants because it holds plenty of moisture but also drains well and lets sufficient air reach the roots.

If you have a heavy, compacted soil type, add organic matter, such as compost, animal manure, cover crops, or organic mulch materials, each year as you work the soil. It may take several years, but eventually the soil will become less compact. Although adding some sand along with the organic matter is acceptable, do not add sand alone. The organic matter has several advantages that sand does not, including increased ability to hold water and nutrients and improved air circulation.

Highly sandy soils hold little water and few nutrients. You can improve sandy soils by adding organic materials. You'll need to add at least a two-inch layer of material to make a marked improvement.

Here's a handy diagram to help you determine your soil type.

If you’re not sure how to best prepare or modify your soil type for planting, consider consulting your local agricultural extension or gardening/landscaping expert, who can recommend the right products for soil care.