Opuntia cactus discoloration - Ask Extension
My common opuntia has developed tan brown discoloration on its main stalk. Plant seems healthy and keeps sending new shoots, which are green. It is sm...
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Opuntia cactus discoloration #890390
Asked November 29, 2024, 3:10 PM EST
My common opuntia has developed tan brown discoloration on its main stalk. Plant seems healthy and keeps sending new shoots, which are green. It is smoothe and non flaky or peeling. I have treated it with both organic fungicide, and alcohol/peroxide washes, in case it is a fungus. It is getting larger. Is it a fungus. If so, do I need to isolate and/or destroy it, or is it merely natural aging of the plant. I purchased at MSU cactus sale .
Oakland County Michigan
Expert Response
Hello,
Can you tell me a little more about your plant? It appears to be a prickly pear cactus. How old is it? How do you care for it? Sunlight, water, fertilizer if used? If you put this plant outside in the summer, what were the conditions? Full sun, soil conditions? When did you notice this scarring? It may be due to sun scald or to some sort of injury the plant had. Have you ever observed insects on the plant?
If you could send me more information about the care of this plant, I would be better able to help you.
I'll wait for your reply.
Can you tell me a little more about your plant? It appears to be a prickly pear cactus. How old is it? How do you care for it? Sunlight, water, fertilizer if used? If you put this plant outside in the summer, what were the conditions? Full sun, soil conditions? When did you notice this scarring? It may be due to sun scald or to some sort of injury the plant had. Have you ever observed insects on the plant?
If you could send me more information about the care of this plant, I would be better able to help you.
I'll wait for your reply.
Common prickly pear. Maybe 2 years old. Kept indoors in a north east window along with a few dozen other cacti and succulents, all thriving and blooming. Soil is cactus mix, pretty inorganic (black gold mix), water every 2-4 weeks or dry to hydrometer, schultz cactus fertilizer per instructions.Never have seen insects. First noticed 2 months ago. Question is if this is fungus, should plant be isolated or destroyed. Plant is growing very healthy with constant growth of new shoots.
On Dec 3, 2024, at 12:45 PM, Ask Extension wrote:
Common prickly pear. Maybe 2 years old. Kept indoors in a north east window along with a few dozen other cacti and succulents, all thriving and blooming. Soil is cactus mix, pretty inorganic (black gold mix), water every 2-4 weeks or dry to hydrometer, schultz cactus fertilizer per instructions.Never have seen insects. First noticed 2 months ago. Question is if this is fungus, should plant be isolated or destroyed. Plant is growing very healthy with constant growth of new shoots.
On Dec 3, 2024, at 12:45 PM, Ask Extension wrote:
I don't see any signs of fungal damage, but you could isolate the plant until you're sure what's happening. The plant looks healthy. The tan areas may be places where the plant was damaged, and the
spots are the plant's efforts to self-heal. However, if the areas are getting larger, it means the problem is still present.
I suspect that the plant may have an insect or mite problem. The following is a short excerpt from an article by Clemson University Extension. I have also included the link to check out the entire article.
Aphids, spider mites, and mealy bugs are the major pests of cacti. Check new plants carefully for pests before purchase. Houseplant insecticide sprays or insecticidal soaps can be used for control. Make sure that the spray you use is labeled for cacti and follow label directions carefully. Scale can also occur and is more difficult to control. You may be able to hand-pick off a light infestation, but you might have to discard the plant if it is heavily infested. https://hgic.clemson.edu/factsheet/indoor-cacti/
I don't believe the plant is severely damaged, but I would isolate the plant, especially if insects are present. Some of these insects are so small you may not notice them. Scale looks like small bumps on the plant. All of these can cause damage leading to the tan markings.
Since you purchased the plant from MSU, you should contact the greenhouse. (1)<personal data hidden>. They may be better able to help you since they would be aware of any issues their plants may have.
It sounds as if you're successful with your cacti, but here is a great resource you may find useful.
https://extension.umn.edu/houseplants/cacti-and-succulents
I hope this information helps.
Have a great holiday season!
spots are the plant's efforts to self-heal. However, if the areas are getting larger, it means the problem is still present.
I suspect that the plant may have an insect or mite problem. The following is a short excerpt from an article by Clemson University Extension. I have also included the link to check out the entire article.
Aphids, spider mites, and mealy bugs are the major pests of cacti. Check new plants carefully for pests before purchase. Houseplant insecticide sprays or insecticidal soaps can be used for control. Make sure that the spray you use is labeled for cacti and follow label directions carefully. Scale can also occur and is more difficult to control. You may be able to hand-pick off a light infestation, but you might have to discard the plant if it is heavily infested. https://hgic.clemson.edu/factsheet/indoor-cacti/
I don't believe the plant is severely damaged, but I would isolate the plant, especially if insects are present. Some of these insects are so small you may not notice them. Scale looks like small bumps on the plant. All of these can cause damage leading to the tan markings.
Since you purchased the plant from MSU, you should contact the greenhouse. (1)<personal data hidden>. They may be better able to help you since they would be aware of any issues their plants may have.
It sounds as if you're successful with your cacti, but here is a great resource you may find useful.
https://extension.umn.edu/houseplants/cacti-and-succulents
I hope this information helps.
Have a great holiday season!
