Hi! I was wondering if you could tell me what these spots could be on my Bird of Paradise? This particular plant also gets scale when I bring it indoors, what can I do to prevent that?
Thank you for your question.
Bird of Paradise (Strelitzia reginae) is a beautiful plant.
It generally does not have many pest problems but mealybugs, scale and spider mites may infest the plants. The large leaves can be wiped off with a soft cloth.
From the picture you have attached, it is a bit difficult to positively identify what is going on but the white spots you are seeing might be mealybugs or edema.
The following is taken from one of our previous posts: Mealybugs are a type of scale insect. As they feed, they cover their bodies with a characteristic white, cottony substance for protection.
These pests damage indoor and outdoor plants by sucking out their sap. They also excrete honeydew over leaves and stems. This sticky exudate is an ideal growth medium for sooty mold which gives the plants a dirty sooty look. It also attracts other insect pests.
We suggest that you look closely at your plant and if mealy bugs are seen, your first line of defense is to physically remove as many mealybugs as possible. If the plant is small, you could remove the pests individually, knocking them into a container of soapy water. Or, you could spray the plant with a hard blast of water, collecting and disposing of the bugs that fall off, and then picking off and dispose of any adults that remain on the plant.
You can also apply an insecticidal soap, carefully following the manufacturer’s instructions.
If the white spots are from edema this may be the result of overwatering, low light or high humidity. Until recently we have had a lot of rain and if your plant was outside this could have caused the edema. Wet areas expand and burst and leave white spots on the leaves. Once the spots dry out they can leave a spray appearance the the leaves.
Check your plant for any drainage issues, and keep in a sunny spot once you bring it indoors. A slow release fertilizer rich in calcium and potassium may help prevent the plant from further edema.
The University of Wisconsin provides a good article on general care of Bird of Paradise.
https://hort.extension.wisc.edu/articles/bird-of-paradise-strelitzia-reginae/
Finally, please find some information from Iowa State University website on treating scale.