It's so devastating when the actually velvety green mint leaves are covered with brown spots. There are two diseases that cause such damage. You can find out what they are and how to combat them here.
Main suspect: mint rust - how to fight it
Within the order of the pillar fungi, a species of fungus has specialized in infesting mint species. They are rust fungi that can infect a plant throughout the growing season. The spores act as parasites so that they do not kill the tissue. Rather, brown spots form around the infection sites. The entire plant is therefore not threatened by the mint rust.
You will appreciate the rapid growth of your peppermint or other variety at the latest when it is attacked by rust fungi. Fighting the disease is so easy:
- Cut back the infected mint close to the ground
- just leave a sleeping eye on the plant
- from here it drives out healthy again
- do not dispose of the clippings in the compost, but burn them
Effective prevention
In order to make it more difficult for the fungal spores to infest a mint, the soil in the bed should be loosened repeatedly. In addition, regular weeding is an effective preventive measure. Avoid wetting the leaves with each watering. Damp leaves are particularly attractive to pathogens.
Leaf spot disease knows no mercy
For laypeople, it is almost impossible to visually distinguish between mint rust and leaf spot disease. A closer look at the distinguishing features is not necessary, because the control methods are the same. Regardless of where the brown spots on mint come from, radical pruning is considered the best course of action.
tips and tricks
The most effective way to prevent any disease of mint is to rotate the crops in the bed annually. At least every two years should be transplanted or repotted. No other mint species or lamiaceae may have been cultivated at the new location in the previous four years.
GTH