
Heather Kolich, ANR Agent, UGA Extension Forysth County
Did you know that 80 percent of plant diseases are fungal? High humidity and wet weather – also known as Georgia weather – are optimal conditions for fungal growth. Fungal and bacterial diseases spread by contact (plant to plant, gloves to plant, etc.), as well as through water and wind.
Rainy weather also fosters rampant weed growth. Weeds compete with garden and landscape plants for water, sun, and soil nutrients, and they’re a haven for pest insects. Among these are thrips, small insects that suck sap from plant leaves and stems. Thrips spread viruses from plant to plant as they feed.
Cleaning and pruning are two ways we can reduce pest issues. Remove weeds and dead plant matter to minimize populations of plant pests and pathogens. Selectively prune and thin plants to allow air and sunlight to dry excess moisture from leaf surfaces. Treatment with fungicides before and during wet, humid weather can prevent fungal infections from occurring. Use a treatment rotation of three fungicides with different modes of action to minimize the chance of promoting fungicide resistance. There are no treatments or cures for viruses, which affect all parts of infected plants.