My San Pedro has been growing quite a lot the past 2 years, but very thin. It was windy the other day and found him tipped over. Not completely broke in half, only half way. So I tipped him back right side up and have braced him in place. I am curious if I need to make a clean cut, around the blackened areas, and repot the top half after it has calloused. Or if I should keep him braced and hope he will heal. I’m just concerned of the blackened parts and the areas around that. It’s not normal looking. Any advice would be much appreciated.

Also wondering why he hasn’t grown wide the past 2 years. I find a lot of my cactus grow thin and long.

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1 Answer 1


Yes, cut the rotten part out and root the top half when it callouses over.

The reason your plants grow tall and thin is because they are not receiving enough sun. Most cactus require a lot of direct sunlight for normal, healthy growth. The San Pedro is one of those.

  • Thank you so much! I think I came to the sane inclusion but couldn’t bring myself to cut him .. I will do it now. Thank you Oct 16, 2018 at 15:18
  • Living in NYC is challenging in finding good direct sunlight. I’m actually considering moving just to find better sunlight. In the meantime, I have this 32watt Agrosun fluorescent bulb on my baby cactus, and they are growing the same, very thin. They are also brown, which I don’t understand either.. Is this bulb sufficient for cactus? What type of bulb should I be using? And can I use this bulb for my San Pedro? Oct 16, 2018 at 15:28
  • If you are going to use the lamp it should be less than 4 inches from the plants. Try to find some white or tinfoil cardboard you can use to put a reflective box around the plants to keep as much in as possible. I moved a few months ago to get better sun for my plants (among other, less important, reasons). Hey, at least you have good food there! Go to Zaros and have a black and white cookie for me!
    – Tim Nevins
    Oct 16, 2018 at 20:22
  • Speaking of black and white Tim, my cactus is now getting more black spots where I made the cut. At the tips and edges of where I cut the top, and the bottom halves. Do I need to cut more of the cactus? Down to where I see no unusual parts? I’ll try to send pictures as well. And yes, I haven’t had a black and white cookie in years ... The things you take for granted living in a city like this.. you know what? I’m going to eat a black and white cookie tomorrow! Oct 18, 2018 at 5:33
  • Cut back until there isn't a hint of discolored flesh. Sanitize your tools with alcohol with each cut. Also try some anti-bacterial plant spray or dust that contains sulfur to try to kill the infection. If there appears to be any bruised flesh cut it out completely.
    – Tim Nevins
    Oct 18, 2018 at 17:33

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