Poor shapes dry as poor shapes. You will have to put up with some unsightliness as you wait for the flowers to dry on your plants, but that's how you allow the seeds to ripen. Heavily infected leaves turn brown and dry. There leaves and flowers were slightly wilted. Use only the most perfect forms. Three days ago: Looked like the Zinnia plants suffered from sun-stroke. 11 years ago. From demure, 6-inch plants to giant varieties growing 3 feet tall, annual zinnias (Zinnia elegans) provide extravagant blooms in every color of the rainbow except blue. Make sure to select plants that are healthy--powdery mildew can transfer to seeds, so don't save seeds from plants with disease. Similar spots form on the petioles and on the stems at or between the nodes. They have grown quite tall. Zinnias charm gardeners with their cheery, colorful flowers and minimal care requirements. Flowers or leaves for drying may be collected anytime during the growing season, from early spring until late fall. CAUSE: Phosphorus deficiency usually shows up first at the bottom of the plant (on the oldest leaves) and progressively climbs up the plant if untreated. Hope your zinnias perk up soon! Also, the only pest I ever had on my zinnias were snails or slugs and their damage appeared as holes or near translucent holes in the leaves. Below is the description of the chain of events that led to the current wilting and drying status of my zinnia plants. RG100. I have grown some Polar Bear and Candy Cane Zinnias indoors for last few weeks. How to Cut Back Zinnias. My Zinnias were bright and beautiful till four days ago. The center of an older spot may drop out leaving a ragg ed hole. Good luck! Hi. The dead tissue has a tendency to crack and tear during wind and rain storms. A few days ago I kept them outside when it was nice and warm around 18 to 20 degrees celsius. Diseases That Zinnias Can Get. Since then the bottom leaves are turning really crisp and just fall apart if you touch them. For many crops, the need for phosphorus peaks during the transition from vegetative growth to budding. There is still new growth on top. fairly large (up to 10 mm in diameter), irregular, dark reddish brown or purple, and dry (Figure 1). Use only plants and flowers free of insect and disease damage. Damage becomes only more obvious after drying. To fix that problem, I just put a little snail & slug bait underneath the leaves at the bottom. Always collect more material than is needed, to allow for damage. Zinnia leaves getting fried.