cactus issue - Ask Extension
I have 2 cacti at least 20 years old. For several years they have been developing the markings shown in the pics. They live in a very bright, partiall...
Knowledgebase
cactus issue #887439
Asked October 08, 2024, 10:17 AM EDT
I have 2 cacti at least 20 years old. For several years they have been developing the markings shown in the pics. They live in a very bright, partially shaded south facing GH for the winter and on my east facing deck outside (sheltered from the mid afternoon sun) in the summer. They are watered with rain water in the GH, and well tap water during the summer. Some of my tall euphorbia had the same issue, and I discarded all of them 3 years ago. Now I need to know if I should do the same with these guys before they infect everything in my collection. Thanks!! PICS attached (I hope)
Lenawee County Michigan
Expert Response
Hello -
I've tried to educate myself on cactus, and I've come up with some links that might help you. My problem is that I can't tell if your spots are scab or corking. From here, I would say it's probably corking. I think it might be caused by our humidity and overabundant rain this year (and last). We have all been affected by climate change, even your cacti.
If you think that your cacti problems fit the description of scab, a fungicide would be in order. I'm leaning towards Corking.
Corking: https://www.sublimesucculents.com/what-is-cactus-corking/
https://youtu.be/g6ur8YvQxKU
Possible Rust/scabbing: https://www.yourindoorherbs.com/orange-spots-cactus-causes-solutions/
Good luck. Let me know if you need any further help.
I've tried to educate myself on cactus, and I've come up with some links that might help you. My problem is that I can't tell if your spots are scab or corking. From here, I would say it's probably corking. I think it might be caused by our humidity and overabundant rain this year (and last). We have all been affected by climate change, even your cacti.
If you think that your cacti problems fit the description of scab, a fungicide would be in order. I'm leaning towards Corking.
Corking: https://www.sublimesucculents.com/what-is-cactus-corking/
https://youtu.be/g6ur8YvQxKU
Possible Rust/scabbing: https://www.yourindoorherbs.com/orange-spots-cactus-causes-solutions/
Good luck. Let me know if you need any further help.
