Factors Affecting Lawn Disease – by Nick Makris
We hope everyone had a happy and safe Independence Day. Here’s an update as to what we are seeing on landscapes, what we are currently applying to your turf and why we are applying each application.
First, we are continuing to see a lot of fungal activity given the high humidity. During the late spring, leaf spot was the most prevalent disease. Recently, red thread and dollar spot are a current problem throughout turf. There are several factors which contribute to these diseases. I will outline these factors to provide a greater understanding to help us combat them:
All diseases need the right environment (consisting of temperature and humidity), they need the pathogen or disease spores present, and they need the correct host. Turf disease spores are spread in a number of different ways. They can be spread by birds; they can blow in from neighboring lawns, and they can also spread from mower blades. These spores are everywhere and it is much more common to have them in your turf than to be spore free.
Fungicide treatments work at killing off any fungal activity, but they last only 3 weeks. In most cases, a single treatment annually will minimize disease activity to an acceptable level; however, if you have disease prone turf or live in an area with high fungal activity, a second application may be necessary. The sooner this is applied, the faster the turf will recover.
Certain diseases infest certain types of grass. If you have a high percentage of bent grass, then leaf spot will be your main issue; if you have a high percentage of Kentucky Blue grass then red thread will be your problem. The best way to minimize disease activity in your turf is to have disease resistant turf. This starts with the correct seed. When establishing turf, using quality seed is critical.
I do not recommend using Scott’s seed or Pennington mixes, or any inexpensive mix. These seed mixes are not entophytic and are highly susceptible to turf diseases even though they come in well and look great at first. For established lawns, it is important to aerate and over seed your turf in the late summer to early fall with a mix of blue and rye grass that is entophytic.
Entophytic grass seed is coated with an enzyme that makes the turf disease resistant. Over seeding with this type of seed each fall will, over time, dramatically reduce disease problems.
We have added iron to our third and fourth application. The iron helps the turf recover from disease and drought stress at this time of year and it will also help with lawn color.