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Wet Weather? Here’s How to Rid Your Garden Plants of Fungus

August 5, 2021

Fungus among us! When the weather is wetter than usual, you can expect fungus in your garden. Even experienced gardeners may not know that fungus can be a huge part of the soil’s makeup. While most fungi are beneficial to your plants, lots of rain can bring black leg, leaf spot, leaf blight, root/neck/crown rot, powdery mildew, and rust to your garden bed.

Warmer temperatures during the day and night, coupled with all that moisture, cause disease and fungus to really ramp up. Everything becomes susceptible to fungus – lawn grass, vegetables and fruit, and ornamental trees, shrubs, and flowers. We can’t control nature, but we can keep a close eye on our plants and try to be proactive on any possible infestation. 

What are the signs that my plants have fungus?

– Reddish to black spots that eventually expand to yellow, orange or brown in color. 
– Sometimes leaves may become white or ashy looking.  
-Plants will also seem to droop or wilt. 

If a plant seems “off”, do not hesitate to take a closer look. If the plant seems well watered and not stressed from drought-type conditions, then most likely it has fungus. 

What is the best way to get rid of fungus in my garden?

The best way to combat fungus is with a fungicide. There are two types of fungicides: protectant and systemic. 

Protectant creates a barrier on the surface of the plant tissue to stop current activity and/or to help prevent future attacks. This type can provide 7-14 days of protection. 

Systemic will be absorbed by the plants and translocate throughout the plant. This type will protect for 14-21 days.

Identify the Fungus

It is important to properly identify the type of fungus and the plant that is infected. This information will tell you about the timing at which you can apply the fungicide. This will also dictate how often to spray. 

If you live in Missouri, the MU Extension has a great chart for identifying what type of fungus you have.

For example, many fruit trees need to begin spraying before bud break and at a rate of every 7 days until spring rains have backed off. It is also very helpful to know the types of plants you have so that you may proactively spray before there is any fungal activity. 

Another example- if you had damage to your lawn in previous years, you would begin spraying as soon as night-time temperatures hit 65 degrees F at a rate of every 21 days. 

Types of Fungicides

Fungicides come in two forms: liquid or granular. The quickest and easiest to use is liquid as it can be absorbed by the plant with ease. 


Once you have identified that you have a fungus problem, apply the fungicide as soon as possible. Fungus will quickly weaken the plant, causing stress and disrupting its normal function. 

Proactive steps BEFORE any attack are best; it is hard for plants to recover from fungal damage and can take the rest of the growing season to recover, depending on the species, weather, age, and additional care. 

Another step you can take is to allow for good air circulation via thinning or pruning. 

Dave Ruzicka

Watering Tips

  • Our watering advice is based on plants living in a 72 degree house. Porch life or humidity could have an impact on its watering needs.
  • Always use tepid water for watering your houseplants.
  • Broadleaf plants need less water in fall and winter, but you should never allow the soil to completely dry out.