Lawn diseases have been very active this summer
Lawn diseases are an annual threat and a frustrating problem to many lawns across the Northern Illinois area during the summer months. With over twenty years of experience in analyzing lawns in the local area, we have seen the most widespread disease damage to leaf tissue in lawns this summer compared to past seasons. Record-setting May rains have led to significantly large amounts of summer lawn disease development. While a lot of lawns go dormant during the months of July and August as the leaf tissue shuts down to protect the grass roots, a dormant lawn does generally not show the damaging effects of lawn disease as the turf is already brown so the damage is disguised as simply a brown lawn.
We get a lot of questions regarding brown spots in the lawn every season, most of which is heat and moisture related, however this season diseases like summer patch, red thread and rust have spread very aggressively. Fertilized and watered lawns show the most significant damage as the non-affected areas stay green while the disease damaged areas become very contrast in brown spotting. Most lawn diseases like red thread, dollar spot and rust only affect the leaf tissue and do not cause long-term damage to the grass once cooler temperatures return in early Fall and adequate moisture is applied. There are a few patch and Pythium lawn diseases that can cause long term damage to a lawn if left unrepaired but are very less common.
Some red thread and diseased spots mid-summer
So how can we repair, fix or cure lawns damaged by lawn diseases? Fungicides can be applied to help prevent or stop the spread of a disease in the lawn once it is identified. These applications are generally not performed unless requested at the initial onset of the disease in early summer or if we know a lawn has a history of lawn diseases every summer. Fungicide applications are not included in most lawn programs as with any disease, over-use of fungicides can lead to diseases becoming resilient to general-use fungicides. Therefore, most applications are performed sparingly once the disease has been diagnosed. At this point leaf tissue has already been damaged and only cooler temperatures of fall will encourage new leaf tissue development.
In severe cases of lawn disease damage, power-seeding is highly recommended to help repair the lawn. Not only does power-seeding these areas fix the damage quickly, it also replaces the weaker grasses (usually fine fescues and ryegrasses) that were affected by the turf disease with newer and more disease and heat-resistant varieties of cool-season grasses like turf-type fescues and bluegrasses. Early Fall is the best time of the year to repair summer damaged lawns with beneficial growing services like aerating, power-seeding and soil enrichment to improve the lawn and prepare it for winter and the following growing season.