Orchid Culture - Questions & Answers from This Month
by Sue Bottom, from the St. Augustine Orchid Society Newsletter.
Email us with any orchid question, if we can't answer it we'll find someone who can! Send photographs too!
Leaf Spotting on Cattleya
Q. I have a Cattleya concern. I’m getting brown markings on leaves with no indentations or waterlines, is it a sign of some type of nutrient deficiency?
A. I don't like those markings at all. It could be virus, but I suspect it is more likely to be a fungal infection. The leaves with the black markings on the upper surface seem to have a longitudinal pattern of spotting on the leaf undersides, which is suggestive of fungal spores. If it is one of the Cercosporoid fungal infections, consider cutting the plant up and discarding the infected part of the plant. Plant only the front sections that are free of the signs of fungus. Then you can consider an antifungal spray to protect the plant going forward.
Happy Phal Won't Bloom
Q. I know I sound greedy but as happy as my orchid is, I have not had flowers in 2 years – since it was purchased. There are tons of new roots growth and new leaves. Is there any way I can force it to take all that energy and make a pretty flower?
A. Yes, there is. The flower trigger for the spring blooming phalaenopsis is some cold weather in the fall. During the initial cold period in the fall, when nighttime temps drop down to say 55F, let the plant be exposed to the cooler weather for 2 or 3 weeks. Don't let it go below 50F. Then, after that cold snap, return it to its cozy spot and wait for the flower spikes to form. Your plant sure looks happy and healthy! (Aug-19)
Water Trapped Inside Phal Leaves
Q. My orchid's leaf had water trapped inside and was squishy. The liquid was yellow. The rest of the leaves were green and the orchid had flowers.
A. That is a bacterial infection that moves very very quickly in Phals. You need to cut off the infected leaves right now with a single edge razor blade about an inch behind where the leaves are water soaked. It is Bacterial Soft Rot caused by Erwinia. There is more information on the SAOS website
describing the problem.
Hope you catch it in time to save the plant!