How do you treat zinnia leaf spots?
Spray plants following rainy periods, as rainy conditions increase disease occurrence and spread. The better fungicides to control Alternaria leaf spot are chlorothalonil, copper fungicides, and mancozeb.
How do you get rid of zinnia fungus?
Remove spent flowers to encourage increased blooms. Tips to minimize occurrence of powdery mildew: * Allow adequate spacing between plants (increased air circulation will decrease mildew and other fungal diseases). * Water early in the day and avoid getting water on the foliage.
Why are the leaves of my zinnias turning brown?
A: Zinnias can be prone to several bugs as well as the most common problem — powdery mildew, which is a disease that turns the leaves whitish, then brown. Aphids and mites are smaller bugs that don’t chew holes but cause more of curling and/or mottling damage to the leaves.
Can zinnias get blight?
Alternaria Blight of Zinnia. Only two diseases are commonly troublesome on zinnias (Zinnia elegans), powdery mildew and Alternaria blight. Alternaria blight is the most common and conspicuous. Spotting of the foliage caused by the fungus, Alternaria zinniae, is the most conspicuous symptom of zinnia blight.
How do you save a dying Zinnia?
After zinnias flower, cut off the old flowers (a process called “deadheading”) to encourage more flowers to form. Zinnias are annuals and will die with the first hard frost of fall. If you want them to reseed, let the last flowers of the season mature fully and scatter their seeds.
How to prevent powdery mildew on Zinnia plants?
To prevent powdery mildew, plant zinnias in full sun. Water the plants midmorning so the leaves have time to dry before evening. Keep the area around the plants free of leaves and other plant debris.
What causes a blight on a zinnia plant?
ALTERNARIA LEAF SPOT OR BLIGHT This widespread and disfiguring disease is caused by the fungus Alternaria zinniae. The causal fungus also infects other plants such as China aster, lettuce, sunflower, tobacco, and tomato. The Alternaria fungus overwinters on seed and in soil.
What to do if you have Zinnia disease?
Apply a fungicide. Whenever possible, water in a manner that keeps the leaves dry to inhibit this seedborn disease. Leaf-like tissue forms where flower parts should be located. Flower-like parts remain green or light green. Often flowers on only one side of the spoke show sympotms. Sepals may be very large or dwarfed.
How often should you spray for Zinnia infestation?
Applying an organic product, such as neem oil, is the safest method of control, but don’t use it on water-stressed plants or when the temperature is above 90 degrees Fahrenheit. Mix neem oil at a rate of 2 tablespoons in 1 gallon of water, and then spray to coat the tops and bottoms of leaves. For heavy infestations, repeat every seven to 14 days.