Dragon Wing Begonia Problem

Asked July 4, 2020, 1:17 PM EDT

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

1 Response

Your dragon wing begonias appear to be suffering from some kind of cultural issue rather than insects. Insecticides should only be applied when you actually see insects on the plant and are able to ID what they are so you can select the proper spray.

The plant in your photo looks like it either has been burned with too much fertilizer or dried up due to lack of water plus overheating at some point. The unusually hot weather we've been experiencing in Michigan this month make that easy to occur. The edges turning brown are indicators of those two possibilities. Also, be careful about is over watering these plants. While they do appreciate moist soil, they do not like wet feet. Be sure your pot is well-draining.

Your moving the pot into a shaded area is a good one during this heat wave of 90+ temps. However, these plants do thrive in full sun. These plants do best with morning sun and light afternoon shade. Beware: Dragonwings tend to burn in hot afternoon sun.

It looks like your caladium and the begonia on the back and right side of your photo are doing fine. So it is possible that the one in front was stunted by an incident of overheating. Cut out the part that is broken/disfigured and give it some TLC. Perhaps it will come out of this funk.

The only spot I see is a small yellow one on one leaf, but I don't believe it is significant. But you should remove that leaf just in case. Here are some common issues with dragon wings:

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.