Euphorbia Ingens Question

[Cactusfrend]

I recently got a Euphorbia Ingens and hadn’t watered it for about a month since it was winter. But I started to notice small areas of browning at the tip, which I initially gently scraped off, but have turned dark and a little soft since then. I’m wondering if this is some sort of tip rot and would require cutting or if it isn’t something to worry about yet?

I have it in an east facing window and take it outside for full sun when possible. The cactus feels firm everywhere else, just would rather catch an issue early rather than too late.

Thanks!

[hegar]

Hello Cactusfrend,

I have had horrible success growing Euphorbias and most likely someone will chime in who has seen this kind of lesion before. Just based on your description and the images you posted, I believe, that a fungus or bacterium has gotten into your plant. This I deduct from you telling me, that the discolored patch is soft and also from noticing, that there is a "water-soaked" margin around the lesion. Scraping the plant - even rather carefully - does open an avenue of entry for a microscopic organism and this may just have happened to your Euphorbia ingens.
Before you decide to lop off the tip of the plant it would be wise to let someone else comment. Of course, if you wait for a few days, the lesion should be enlarging, if the cause of it is a pathogen.

Harald

[Cactusfrend]

Thanks Harald!

I’ll see if anyone else chimes in, otherwise I’ll give it a few days to see if it starts to spread and see If it is in fact some sort of pathogen. If it doesn’t enlarge would you recommend just leaving as is/is it something the cactus could naturally recover from?

[hegar]

One of the signs of a pathogen being at work is the spread of it. So if it is either a bacterium or a fungus, the lesion will enlarge and there may even be additional ones forming. Sometimes, a plant just becomes injured and it is able to compartmentalize the affected area. Then you will just have a callus (scab/scar) form and the plant will be fine.

Harald

[Cactusfrend]

I have kept an eye on my ingens for the past couple days and have been putting an at-home fungicide on the markings. It does appear as though the color change is spreading, although perhaps not that quickly and no longer quite as dark (Attached are photos). Given the current situation would it be best to proceed with surgery? If, so what is proper procedure and future care.

Thanks!