We Get Cactus Canker Questions
We get the fun questions!
I think the cankers on my cacti are a fungus. Regardless, I am not sure whether there is any hope (treatment) for the first one and whether the second is suffering from the same problem. Any help/advice would be much appreciated. I live in Oakland, CA.
It does look like a fungal issue. You can treat with Neem Oil, which is a natural and usually effective fungicide. We usually use it in a 1-2% solution in water with a drop of soap as an emulsifier. Spray to the point of run-off on an overcast morning or in the evening, but not on a sunny day as oil treatments on sunny days can cause burning. Retreat after a week at least twice. It should deal with the fungus, though the scaring will always be there, though eventually it will bark over and just add character to your plants. We carry Neem Oil at the nursery, and can talk you through it’s use.
Thanks for the prompt reply. I will stop by, say hello and buy some Neem oil from your store.
I was contemplating getting rid of the cactus because it looks so sick, so you saved it.
BTW, can this fungus spread (wind, etc.) to other cacti in the garden?
Love your blog and your helpfulness.
I do recommend spraying the plants that are near the infected one, the fungus can spread.