Suddenly my old wonderful cactus had new growth dying. I cut off the first bad part and it seemed to heal and do fine. Then all the other new growth has turned gray and is dying. Doesn't seem like over watering. Can cactus get aphids or other critters that would cause this? I was getting ready to repot, but decided to ask all you experts first. It's in a clay breathing pot and hasn't been repotted for several years. They have small roots don't they? Thanks for any help. While unnamed, it does feel like member of the family.
Some cacti have big root systems, other have small. They can get aphids. Generally they should be repotted more frequently. Apart from that I am not able to advice you as long as I don't know what kind of cactus it is (if it is a cactus ...) and have more details on what the damage looks like.
can you post a pic of it? from your description, i'm thinking fungal. yes, some critters do attack cacti - spider mites and mealy bugs are two. i don't think aphids bother them, not sure though.
Thanks everyone for your comments. I'm out of town for a few days and will send pics when I return. I noticed that the gray dead new growth areas would rain "dust" (spores?) If I tapped them. I did not repot yet. I will try to post a picture of a piece I rooted a few yrs ago, which is located in another house and is healthy. Thank you all for the help-its very distressing. Hope its not too late.
Trying to attach picture of a piece I rooted a few yrs ago located in different house. Its healthy but should help identify type of cactus. I noticed that the sick one emitted clouds of dust (spores?) From the dead new growth when tapped gently. YUCK. Thanks everyone for your comments and help.
Hello all- Attached is a photo of my old cactus whose new growth has died and turned gray. No rot, just dying new growth. My next desperate step is to repot. I gave it Miracle grow with my other plants every few weeks, just a splash. Wonder if its something that has concentrated or leached out of pot. Could it possibly be that it has outgrown old pot? Should I try to separate and get rid of old soil or would that shock the roots. Should I water well after repotting? Doesn't look like too much watering but not sure.Wonder if I sent to USDA Extension service if they could identify problem. Thanks for any suggestions.
Photo attached this time - I'm getting ready to repot out of desperation. Maybe the new growth is dying because it needs more soil or nutrients? Advice welcome.
It is a a monstrose form of a Cereus of some kind (peruvianus?). I wonder if the grey stuff could be Borytris? I have not seen it in a long time, so I am not sure. I don't think it has to do with water/nutrients. Is it spreading? The pot seems big enough, perhaps even slightly too big.
no need to repot - what you have is more than sufficient. definitely fungal and boytris is likely correct. you can treat with fungicide and i'd probably cut off the infected parts as well (cut below where infected so you get rid of all the bad stuff). no experience with infection of this kind - i hope you can salvage it!!
THANKS ALL FOR THE DIAGNOSIS! Yes, it has spread from just one new bud, and now ALL the new growth has it. I will get some fungicide and try to salvage. Seems like it showed up out of nowhere, although I do have another plant that seems to have a fungus, where the tips of the leaves turn black (corn plant variety?). Wonder if it jumped from one to another. Maybe I should trash that one, if its spreading fungus around. Or maybe I can save both. Thank you all very much. I worry that the spores are all over the place, since it send up puffs of gray "dust" when disturbed. Off to the nursery tomorrow for fungicide -- again, thanks. I'll let you all know if it survives. (At least I have its offspring for memories....)
Fusarium is another fungus that results in gray stems, but the epidermis usually becomes reddish first. Both Borytris and Fusarium are likely to spread to other plants, and both are very difficult to stop. The plant should be thrown out (or, preferably, burnt). Fungal infections is something that most cactus growers experience now and then, especially those who grow certain opuntioids.
so you think i need to euthanize the cactus (and corn plant) and not try to save, as someone else suggested? the fungus, as you could see, is all over the cactus, on every new stem.
If it was my plant my first move would be to cut off a piece or two of the branches, 10-20 cm from the tip, assuming that there were no gray patches on it. If the cut looked good, I would wash off eventual spores from the skin, treat the wound with sulphur dust (and the rest too) and let it dry until spring. Then I would cut the main stem about 20 cm below the closest gray area and see if it seems healthy. If not I would cut off another 5-10 cm until the cut is completely green and then treat it with sulphur too. The knife should be sterilized between each cut. (Note that I don't have access to good fungicides, hence the focus on sulphur.)
ok, first i need to go from metric to inches. you let it dry out for months??? last time i just stuck it in soil and it thrived. i must have just been lucky. i'll get fungicide and try your suggestions. i noticed that some of the new growth goes far down the main trunk. i'll wait to hear back on your answer to whether you can tell from inside plant how far down to go, or just from outside green area, which is what i suspect. i don't understand what you mean by splashes? was spore in soil and by watering, it splashed on plant?
The garden center knew nothing about cactus and fungus, but fortunately you gave me some guidance. i have several cuttings now. poor cactus is less than 1/2 the size it was before - basically a stump now, but hopefully it will survive. So now it has been pruned and sprayed with a sulfur solution. Time will tell...
I'm sorry to report that my dear old cactus, truly a member of the family, expired shortly after surgery. Unfortunately, all of the careful cuttings I made also developed the fungus almost immediately. I am grateful, however that a cutting I made a few years ago has survived in a different location, so memories are preserved. I'm still somewhat baffled that I could kill a cactus, since they seem so darn tough and handle neglect and abuse so well. I guess they are sensitive under that tough exterior ;-) Many thanks to all of you who offered help during this ordeal. Next time I hope to have something more cherry to report! Elin
Next question - how do you dispose of sulfur - both the water mixture and the dry dust. I know it is considered "green" but I also think it is toxic (albeit natural)
So it had spread too far after all (looked like it, but I wasn't sure). Yes, they are surprisingly sensitive. Many live in dry areas where fungi are uncommon, which can be why they are a little sensitive to them. Sulfur is something I just throw out with other garbage. Then it will either be burnt or metabolised by microorganisms in a landfill. Nothing to worry about, unless you plan to throw away enormous amounts (which I doubt). Why do you want to get rid of it?
I figured I wouldn't need it again, and I'm really trying not to accumulate any more "stuff." But now that you mention it, I do have a fungus (?) problem with my lilacs and if I break down and get roses, I would probably need it to. Maybe I don't have to trash it after all!
