BCSS - Forum

Hi all, I've got a Pilosocereus chrystostele (I think) that I've had for a few years. It's now got three decent stems on it, but unforunately the largest stem has developed some rot and black spots. It's on the same watering routine and in the same window that it has always been in so I'm not sure what has caused it. Photos below:





There's no sign of rot in the other stems or on any of my other plants. I'm considering cutting this stem out entirely if it's beyond saving?

I dont think you can save the stem. If you cut the top off well above the rot, you may be able to get the top going as a cutting.
I'd also unpot it, and cut the bad stem off from the two good stems (assuming the rot hasn't spread across to them), and leave a week before potting up.

Have the bases always been that thin, just wondering if it's a bit of scorch ?, as there is varying degree's of scarring on the three stems.

Thanks Ralph, I'll give it a go, hopefully the top of the stem isn't too far gone for a cutting.

Hi Tina, yes the bases of all three are skinny and corky, but I always just assumed it was a species thing since I don't seem to get it on my other cacti. Do you think it's possibly not liking being in full sun?

HI,

Did you buy this plant with the three stems already growing together, in which case I suspect that this is three separate seedlings put in a pot together as a lot of wholesalers do now. Also if this is the case then the problem is unlikely to have spread to all three stems.

I suspect that in the past this plant has not had enough water or food, it is not cold damage as you keep it indoors. I also think that this is not Pilosocereus chrysostele but is Vatricania guentheri. In which case this is a very tall growing plant which flowers for us each year having reached a height of around 7 or 8 feet.

I also think that the black rot, a kind of weeping, will with the better weather seal itself and stop going any further but of course will still not be pretty to look at. However if you do cut the top off it should root for you as Ralph states.

Good luck, Suzanne

Hi Suzanne, I bought this as a single stem a few years ago. It was an unlabelled garden centre plant I believe, as most of my current collection are. I've just had a root around and the three stems are definitely a single plant so I am a bit worried about the other two stems.

Lack of feed could definitely be the culprit, when I initially bought my cacti I was under the impression that they didn't particularly need feeding so the only feed they had for the first few years was when they were repotted. The newest stem seems fairly happy and is a much darker green colour than the older ones, so hopefully even if I have to cut off the rotten stem I can give it some TLC this year and end up with a really nice plant down the line.

Thanks for the ID, I'd be very interested to see your 8 foot specimen, the tallest stem on mine is only 9 inches!

Many thanks,
Alex