I've tried Neem oil with soap. Had no luck with it. Steve, I hear you about the bees. My torch cactus flowers were crazy this year, as in the hundreds. Bees were all over them Anyone tried Bonide systemic insect control? The active ingredient is Acephate. The other thing I am considering. Australian...

Thanks for that Steve. Why do you say Imidacloprid soil soak should not be done on in-ground cacti ? I'm in Los Angeles, & had a bad infestation of Agave snout weavel last year. Never noticed until 2 of my blue glows just fell over. The little weavels live at the base of the plant and roots, so ...

strange scale appearing on torch cactus. On some appears to be emanating from base of plant. On others, there is very bad scaring where flowers once were. Any idea what this is ? I've tried systemic fungicide over several weeks. Also Neem oil. No luck. Seems to be getting progressively worse. Any id...

strange white waxy droplets occurring on torch cactus and other Trichosurus. I can see no obvious signs of insects, even if I use a magnifier. Tried Neem oil. No luck. Are these mealybugs?

Any idea what to do with my San Pedros ? I split 2 big pots last year, to make about 10 new plants. Half are growing fine, and very green. The other half ( same direction, same sun, same water, about 10' away ) have not grown 1" the whole of last year. They are also very yellow. Poor things are...

Thanks for all the responses! I think I'm going to go for 50%. Does anyone have a suggestion of where to buy it? I'm in Hollywood, Yes, we can get real problems with the 100F mid day sun, day after day. I use shade cloth for new plantings in summer. You can get by the yard in Anawalt. Home Depot al...

Thanks Harald, I decided to try some surgery. Once I got into it, realised plant was beyond saving. The pictures I took were some time ago, and I compared to how it is not. The fungicide is not stopping the problem. I cut whole plant back to the ground. Will do some preventative spraying once new gr...

I planted this Consolea Rubescens last year. Was doing fine, now, not so good. I've tried sulphur and copper based fungicides to no avail.
Don't want this spreading to other opuntia. I'm considering digging plant up. Any suggestions ?
Thanks
Steve

Thanks Harald,

It's a very large specimen, with multiple offsets. I completely cut out the offset in the picture, and now just cut out the other diseased areas.
Teated all with sulfur. Hopefully that should have got it. will let you know.

one of my large trichocereus has black crown rot on one of the offsets. See pic. There are several black spots on some of the other crowns, but quite small as of now. The spots are raised up from the surface, and very hard. Almost like a lacquer . I've cut out the main diseased part, and treated wit...