Dragon Wing Begonia Problem
I grow dragon wing begonias every year and have never had a problem. I have 2 pots on the porch, only one was having an issue. One was in total shade and the other one was in mostly shade (gets a couple hours of late sun). At first, I thought the leaves were sun scorched, so I moved the pot next to the other pot. The bad pot was getting worse, so I ruled out sun scorch. So I sprayed it with an insect and disease control because I still didn't know what the issue was. The pot continued to get worse, and I saw little flying bugs, so I sprayed it with an insect control (1 week later). Now, it's on the other pot too. The new leaves on both pots are coming out wrinkled, stay small and have the same issue, then fall off. Help please! They were gorgeous in the beginning!
Wayne County Michigan
Tan spots on leaves and plant rot at the base are result of fungal disease (Botrytis). Treatment: This disease is common with rooted cuttings and is best prevented by using a clean, pathogen-free medium. Discard affected plants and start new plants form clean stem tip cuttings.
Spots with yellow halos on the leaves are results of bacterial leaf spot.
Treatment: Remove affected leaves and increase air circulation. Discard infected winter blooming as they carry these disease throughout their system.
Mildew is not the problem with Begonia coccinea that it can be with other begonias, but fungal disorders can certainly set in if plants are too crowded, watered from overhead or have poor air circulation.
Watch out for mealybugs and aphids on foliage.
Treatment: Control them by dabbing with alcohol-soaked cotton swabs. Repeat the treatment every 5 days until the problem is solved. Do not use oil sprays to control pests on any begonias. Neither of these insects fly, and you will see them.