Maintaining a lawn often requires regular management of certain lawn diseases. Whether you’re growing warm season or cool season grass species, diseases can quickly overtake and destroy yards.
The time of year for warm season turfgrass disease vs. cool season turfgrass disease also differs as warm season grass, like zoysia, St. Augustine, bermuda grass, centipede, etc. are more prone to disease outbreaks in the spring or fall while cool season grasses like fescues, ryes and bluegrass are more susceptible in the summer.
If you’re looking for a solution to prevent lawn diseases in your yard, there are many cultural practices to consider trying. Today, we’ll walk you through the best cultural methods for lawn disease prevention in warm season and cool season lawns.
What is Lawn Disease?
Lawn diseases come in many forms, ranging from leaf spot, brown patch and dollar spot, to fairy ring, rust disease and snow mold. In general, the source of these lawn diseases is due to plant pathogenic fungi.
For fungus to spread and be present, there needs to be three main factors:
- a host, living or dead organic matter (thatch and leaves),
- the right environmental conditions, such as shaded, moist areas to grow in,
- and the pathogen.
These three factors are also known as the disease triangle. All three must be present for the fungus to grow and spread.
To prevent these diseases from occurring, it is important to first understand the different types of lawn diseases and how to identify them. You can do this by taking a look at our disease identification article.
Once the disease takes over the lawn, it will remain active until treatment is used.
While a fungicide is the most effective way to treat lawn diseases, you may also avoid lawn issues by practicing proper lawn maintenance.
Cultural Practices for Preventing Lawn Disease
There are many cultural methods for lawn disease prevention, including proper mowing techniques, infrequent watering and proper fertilization.
Regular mowing at your lawn’s appropriate height is an essential cultural method for eliminating diseases in your lawn. In addition to promoting an aesthetically pleasing lawn, proper mowing allows for water absorption in the roots to encourage a healthy lawn.
While it may appear that any mowing will prevent grass diseases, improper mowing can actually cause more harm than good. In fact, mowing your lawn improperly may create an environment ideal for diseases to develop.
For example, you should never remove more than ⅓ of leaf blade at a time. This stresses the grass and it will have a harder time recovering, making it more susceptible to disease outbreaks. Ensure your mowing blades are sharp to avoid tearing up the grass.
Maintaining proper soil quality is another key for preventing lawn diseases. Oftentimes, grass diseases appear due to a lack of nutrients in the soil. The lack of nutrients indirectly leads to disease as your lawn becomes weakened, making it more susceptible to disease outbreaks. Test your soil to find out which nutrients it needs.
In any case, to achieve the proper soil in your lawn, you will likely need to use fertilizer several times throughout the year.
Sod University recommends the Lawnifi® Fertilizer Annual Subscription program. Lawnifi, a cutting-edge fertilizer, reduces the age-old problems associated with ionic nutrient lockup.
Powered by Catalyst TechnologyTM, Lawnifi nano-sizes its nutrients so that more of them are absorbed through the roots and leaves of plants.
As a result, larger amounts of nutrients are efficiently delivered to plants. The amount of product that needs to be applied is significantly reduced while using 80 percent less nitrogen and yielding better results.
With less nitrogen usage, Lawnifi fertilizers work to balance C:N (carbon:nitrogen) ratios in your soil for optimum soil and microbial health. Learn more here.
Be careful not to over-fertilize your lawn, as this may lead to other issues. In some cases, excessive amounts of nitrogen actually helps disease spread as it will also feed on nitrogen. Applying fertilizers with too much nitrogen, especially in a fast-release form, also encourages unnecessary growth in the leaf blades. This provides more opportunities for fungal penetration.
In many cases, overwatering is the cause of diseases such as brown patch, dollar spot and leaf spots. Chances of disease outbreaks are even worse if the overwatered spots are located in shady areas. Learn how to manage grass in shady landscapes here.
To prevent grass diseases in your lawn, it is important to practice proper irrigation. Generally, grasses require deep, infrequent watering during the early morning or late evening. If you’re using a sprinkler system, consider conducting an irrigation audit to find out how much water each zone in your lawn receives.
If your lawn contains sandy soil, you may need to water it more frequently with less amounts of water. Furthermore, lawns may require deeper watering when temperatures increase during the summer.
Soil Aeration and Thatch Removal
Aerating your lawn serves to reduce soil compaction and provide more room for roots to expand and deepen into the soil. As a result, this increases the grass’s ability to recover from damage and decreases the likelihood of disease, or even insect invasions.
It also permits access to an increased amount of oxygen, water and other beneficial nutrients for the grass.
While 0.5 inches of thatch actually provides benefits to grass like warmth for roots or a reduction in water evaporation, too much thatch is an optimal environment for certain diseases like fairy ring, gray leaf spot or summer patch. Learn more about aerating and dethatching landscape projects here.
Organic composts applied to lawns successfully suppress turfgrass disease and are becoming more popular. Organic composts also help soils break down chemicals faster than soils without compost applications. Learn more here.
All of the above tips serve as professional advice for lawn disease prevention. However, when lawn disease is currently present, the best thing to do is first identify the disease and then purchase a fungicide effective for that turfgrass disease. You can identify the disease by using our disease identification blog and by sending a sample into your local university extension office.