Fusarium patch is the turf disease that strikes fear into the hearts of many greenkeepers. It can appear overnight and seems to spread like wildfire. The conventional response? Reach for the strongest fungicide you can find and hope for the best.
But here’s the truth: fungicides treat the symptoms, not the cause.
Fusarium thrives when your turf is under stress, your soil biology is out of balance, and your maintenance encourages thatch and weak grass. Chemical fungicides might suppress the symptoms for a few weeks, but they also damage beneficial soil microbes, reduce disease resistance over time, and create a vicious cycle of dependency.
In many bowling greens, particularly those constructed with high sand content, the soil environment is biologically inert. These rootzones often lack the organic matter and microbial life that are critical for natural disease suppression. One of the key microbial groups missing in these systems is the thatch-degrading fungi, especially Trichoderma species.
Trichoderma fungi are essential allies in a healthy green. They compete with pathogens like Microdochium nivale (the Fusarium culprit), degrade thatch by producing powerful enzymes, and help to create a soil environment less favourable to disease. However, these beneficial fungi are frequently underrepresented in sterile, sandy rootzones and are particularly vulnerable to chemical fungicides, which can decimate their populations alongside the pathogens.
When fungicides are used repeatedly, they don’t just suppress disease temporarily; they erode the very microbial networks that would naturally keep disease in check. This explains why many greens find themselves caught in a cycle of recurring outbreaks and escalating chemical inputs.
The Natural Solution Stop thinking of disease as an enemy to be eradicated. Instead, treat it as a messenger telling you that something’s off. Focus on improving air movement, reducing surface moisture, encouraging perennial grasses, and feeding the soil food web with biostimulants and natural inputs. Over time, this builds a living, balanced soil ecology that resists disease naturally.
Want to dig deeper? Read more about the science behind Fusarium and its natural controls here: