Better gardens begin with a soil test

COLUMBIA, Mo. – When soil is workable, start your gardening season off right with a soil test.

A soil test reveals nutrient levels and pH balance, which are critical factors for successful gardening. “A soil test is the first step for building healthy soil and ensuring gardening success,” says Rasel Parvej, director of the University of Missouri Soil and Plant Testing Laboratory.

MU Extension horticulture specialist Kathi Mecham highlights three key reasons to test soil in early spring or fall:

• Save money by avoiding unnecessary fertilizer purchases.
• Protect the environment from nutrient runoff.
• Grow bigger and better produce and flowers.

Following soil test recommendations helps gardeners apply only what their gardens need. Soil tests also identify harmful contaminants in the soil, such as lead, which is especially important in urban areas.

“Although our regular soil test does not include lead or other heavy metals, the MU Soil and Plant Testing Lab offers heavy metal package that includes lead (Pb), arsenic (As), cadmium (Cd), chromium (Cr), cobalt (Co), antimony (Sb), etc.,” says Parvej.

Soil tests tell the nutrient content of the soil so that the gardener knows what nutrients are too low or too high. Results also tell the soil’s acidity/alkalinity (pH), which dictates how the soil can absorb available nutrients.

The lab provides specific instructions for the specific nutrients and amounts needed to correct imbalances, says Parvej. MU Extension horticulture and agronomy specialists also can help interpret the results.

Applying the correct amount of fertilizer helps with two other lawn and garden challenges: choosing the right plant and excessive pruning. Not all plants are suited to all soils, so a soil test helps you choose the right plant in the right place, says Mecham. Also, too much fertilizer can lead to sudden plant growth for trees and shrubs, requiring extra care of the plants.

Plants can become stressed when there is an overabundance of nutrients, which makes them more susceptible to pests and diseases.

For the most reliable results, Parvej recommends following the instructions listed on the lab’s website or watching this video.

For more information, consult the MU Extension publication Soil Sampling Depth and Collection Techniques for Soil Fertility and Soil Health Testing.

Accompany your sample with the soil sample information form.

You can mail your samples or drop them off on the MU campus. There is reserved parking north of the MU Memorial Union and west of Mumford Hall for the convenience of those dropping off soil samples. 

Send samples well enough in advance so you have time to purchase the necessary supplies for the gardening season, advises Parvej.