I Didn’t Know That!
By Mary Gifford, Colorado Master Gardener
Got Microbes?
Regenerative garden practices were discussed in the January 2026 issue of The Garden Buzz but one important aspect deserves a closer look – microbial life. Microbes, specifically beneficial soil bacteria, play a huge role in decomposing organic matter like plant litter and in nutrient cycling. These two processes are critical to growing healthy, disease-resistant plants. It is useful to have a scientific measure to determine if there are more beneficial soil microbes after regenerative practices are utilized. The “Haney Test” is one such measure.
In 2024, the Cheyenne-Arapahoe Park demo garden sent a soil sample from one of their plots to Ward Laboratories to be analyzed using the Haney Test. This soil test focuses on two categories:1) number of microbes and 2) nutrient content (carbon, nitrogen, phosphorus, potassium, aluminum, iron and calcium). The more beneficial microbes there are, the healthier the soil. The Haney Test was performed again on the same plot in October 2025. Results showed a dramatic increase in microbial life in just 1.5 years. The microbial respiration score from 2024 was 47 ppm CO2C (ppm = parts per million). The October 2025 score was 101 ppm CO2C. That is over a 100% increase in microbial life from the previous year! The goal for very healthy soil is 101-200 ppm CO2C. [The Haney Test measures microbial respiration to determine the amount of microbes in the soil by measuring CO2 released from the soil in a 24-hour period. Respiration for microbes is the breakdown of organic matter to produce energy for themselves.]
As the lab analyses show, the soil at the Cheyenne-Arapahoe Park Master Gardener “community” plot became much healthier after just two seasons of applying regenerative practices. Ensuring that a garden receives enough organic matter, such as compost and decaying cover crops, and maintaining live roots in the ground will allow for a robust soil microbe population. Building up soil microbes is a truly important piece of growing healthy, disease-resistant garden plants.
