Question
Cactus Pic
Hi, Maureen - I抦 hoping you can help me? I have a 5 foot tall cactus that I love, in a large pot in my New York City apartment. I抳e had it for 9 years with no issues ?It gets decent light (I live on the 30th floor, with western exposure) and I water it about once per month in the summer. I just noticed that the base of one of the three trunks in the pot has turned black and shriveled, starting at the soil line and extending up about 1 foot (see attached pics). The black area covers the entire circumference of the trunk, but it looks and feels ok above the black area. This seems to be the only plant in the pot that is being affected ?the other two still look/feel normal. Can I cut and save the upper portion of the affected plant and re-root it back in the pot? My fear is that I will lose the entire plant, along with the others in the pot if the rot spreads in the soil. Since I live in an apartment and the cactus and pot are very large and heavy, I don抰 think it will be feasible to entirely empty the pot, change the soil, check the roots, etc. How should I handle this? Thanks!
AnswerDear Laura,
I only received one picture but from what I can see the rot on that one arm is extensive and you can't tell what is going on with the other two unless you take the plant out of the pot and look at the roots. I wish there was an easier way. You can certainly try to reroot the unaffected part of the arm but not in that soil.
Listen, I know it's a challenge and a little overwhelming but you but you absolutely can take the plant out of the pot, see if that arm is indeed connected to the other two, separate it from them either way, check all the roots and for heaven's sake get rid of that fungus infested soil and repot, sans infected arm. At least that way you'll hopefully be able to save the rest of the plant.
I've done it by myself and yes it's a mess and if you have any friends enlist their help. You need a bigger pot anyway. It should be 1/3 the height of the plant and a bit wider for stability. Get good soil. I use 1/3 each of peat moss, perlite or sand and soilite or some sterilized soil mix. Take a newspaper and roll it up so you can wrap it around the plant. I would cut the pot away from the plant if you can, or take a knife and go around the pot so you can lift the plant out. You lift with the newspaper to prevent getting stuck (this is by the way, a Euphorbia, not a cactus. IMPORTANT!! and I should have said this sooner, wear gloves. Euphorbias secrete a latex like substance that can cause a rash#.
Lay the plant on it's side, get rid of as much dirt as possible from around the roots, separate the infected arm and look carefully at the other two. Cut off any dead roots and see if there is any rot at the base of the other two limbs. If they look ok plant them in the new pot with the new soil and don't water for about a week. You may have to stake them initially.
The reason I am so insistent on you going through all that work is that black rot most often starts in the roots and travels up. I'm sure you have more rot in the sick arm that just hasn't reached the outer tissue. If you want to re-root that arm do this: Get a sharp knife, sterilize it with alcohol and cut at least two inches above the rot. If the tissue is discolored in any way you need to re-sterilize the knife and cut to where the tissue is healthy. Lay it aside until the cut end calluses over #it will look kind of corky). That will take at least a week. Then, in another pot plant the cutting just deeply enough in barely moist soil to keep it upright. Don't water it again until you see new growth. You can mist it in the meantime. It will take quite awhile to root.
It's a beautiful plant and certainly worth saving. Please let me know if you have anymore questions and concerns.
good luck,
maureen
P.S. Get that old dirt and dead stuff out of your house!
