Hi folks,
I have a Trichocereus terscheckii plant around 20cm diameter, 50cm high which was subject to a period of unfortunate neglect a while ago, in which it became rootbound and I took my time remedying the situation. It stopped growing and started looking a bit worse for wear. I eventually planted it out in an outdoor bed in which some Trichos were thriving, and a couple not really doing much. This one in particular just sat there, ribs a bit drawn in, a bit yellowish, and never recovered. Several years later after no change at all, I dug it up and inspected the roots for signs of pest infestation or disease, and the roots looked problem-free. I put it into a new pot with spare room for root development, in a good cactus mix I'd made up that was keeping numerous other of my Trichos happy and healthy. Must be a year on from then, and still the plant has shown no change (ribs not filling out, no new growth). It's been getting plenty of water and the occasional feed. Everyone I've asked has drawn a blank on what the problem could be.
Does anyone here have any thoughts on the matter?

The closest thing that happened ime was a seedling which I gave too much sun

It took over a year for it to start showing signs of new growth

I'd say to leave it alone and not do anything extreme.

It should recover.

Hopefully dg or some other cactus expert can chime in.

Good luck

Are the roots all bundled up in the shape of the pot it was root bound in? When you pulled it out of the ground was there any new root growth from the last time you saw the roots?

When they get root bound like that you have to literally cut the roots that were smashed up against the pot off so it can throw some new ones out and get a healthy root system going. I actually trim the (small) roots on any cactus when re-potting. Not all the way down, but quite a bit. I've noticed that they like to abort lots of their roots after being root bound/sent bare root/re-potted. When they are overly-root bound they just end up being a rotting hazard/dead mass blocking off any new root growth and should be removed. I make sure not to water it for a few weeks after the re-pot to let them heal and start some new roots out.

Anyways, it sounds to me like a case of a non-functioning root system.

If the roots are no longer functioning you could graft it to another well rooted cactus. Some PCs are great for this as they are fast growing and root well.

thats a giant plant to be grafting (7" wide and 20" tall- pc would not be a good choice unless you could do a spear point graft, but the base of the terscheckii is going to be too woody for that by far)


Wira,
can you post pictures?
if its not growing a shadier spot than the rest of your trichs is probably a good idea

i probably wouldn't be cutting any portion of it even if the roots are corky

ps, a cacti that is not growing needs very little water, and no feed really. too much water, sun and food are not good

You are correct dg, I must have not paid attention to the size.

Another option would be to cut off the existing root system, which appears not to be functioning, dust the cut surface with rooting hormone powder, let it callous over and place in fresh compost mix. But I would wait until next spring.

This is sort of what I was suggesting. Sound like the current root system is kinda screwed up. So if it got a new start it would be able to grow a new, healthy root system. What I usually do though is keep any really big tap(ish) roots on and cut off all of the others. Anyways, what spanishfly suggested, I think, is the best option to get it going again. Definitely wait until spring though.

Hi,
thanks for all of the input everyone!
The roots didn't seem all massed together when I dug it up - at least I don't think so, it was a while ago now. It's been sitting in the new pot in a partially shaded position. I think I'll take the advice and trim and dust the roots, and hope for the best.

Hi,
thanks for all of the input everyone!
The roots didn't seem all massed together when I dug it up - at least I don't think so, it was a while ago now. It's been sitting in the new pot in a partially shaded position. I think I'll take the advice and trim and dust the roots, and hope for the best.
The only pic I have handy right now is from a few years ago - it looks a bit more yellow and thin now.

One of the things i learnt growing cacti is to put them where they should grow and leave them there and leave them alone .

Another is that it doesnt matter what you do some wont grow and stay small .

The cacti in the picture looks to me to have to much sun .