In the 2009 edition of The Yolo Gardener, Linda Parsons, Yolo County Master Gardener, wrote the article “Foiling the Fungus Fairy”. Click here to read the full article or continue on to see our shortened version.
Seeing spots? White, black or rust colored blotches or lesions usually means fungus has arrived!
For diseases to occur, plant pathogens must come in contact with a susceptible host plant. Therefore pathogens can be past on to plants through transplants, soil, humans, animals, insects, infested seeds and wind or water. The most common garden fungus diseases are powdery mildew, black spot, rust and sooty mold. They are most problematic during the spring and fall seasons due to temperatures and humidity fluctuations.
Follow these easy steps to avoid fungus attacks:
- Select high quality plants and seeds. Select plants with healthy looking leaves and strong stems.
- Do not plant too early. Plant growth may be slowed by cold temperatures which makes them more susceptible to attack by disease-causing organisms and insects.
- Rotate crops. Grow your crops in different parts of your garden each year, be sure not to rotate crops with those in the same plant family.
- Avoid over-crowding the plants. Crowding plants creates a moist, humid environment that is favorable to diseases.
- Water early in the day. Plants that remain wet throughout the night are more susceptible to disease.
- Remove diseased leaves, flowers, and fruits as soon as they are noticed. Disease is easily spread by wind, rain and overhead watering.
- Mulch! Mulch prevents soil that may harbor disease-causing organisms from splashing on to plants.
- Fertilize carefully. Avoid over-fertilizing because too much nitrogen promote tender, fast growth, which is susceptible to attack by fungi.
- Keep insects and insect damage to a minimum. Insect wounds provide entry points for disease-causing organisms.
- Practice good gardening sanitation. Always start with a clean planting site.