Hey there cactophiles!
I have recently acquired three nice looking bridgesii specimens about 13, 14, and 17 inches long by about 2.5-3 inches wide at the base. My original intention was to extract them, but they are just so darn good-looking that I think I'd like to put one of them in the dirt and try my hand at cultivation. My only hands-on experience with growing things was with a handful of somewhat lanky sad-looking cannabis plants a few years back, but I would really like to continue learning and eventually put together a nice little sustainable garden.

The cacti already have a pretty well-established root system, so I figured it would be a good starting point for a beginner. Eventually I would like to learn how to grow from seeds or at the very least seedlings, but learning how to keep a mature rooted cactus alive seems like the easiest place to start.

I live in a dry high desert climate area with hot summers but frigid, subzero winters. My plan is to plant the smallest one in an 8 inch pot, filled with a mix of 50% Miracle-Gro Cactus Palm & Citrus Soil and 50% perlite, with a 1-2 inch thick layer of broken ceramic pieces in the bottom for added drainage if necessary. I have a couple of lights which my mother has successfully used for other plants, but I am not certain what kind of bulbs are in them. The room I will have to keep him in is not especially well lit (as you can see from my photos), and it does not receive much sunlight at all.

Now for the questions. What temperature would be ideal for this indoor cactus during the winter? How often should I water this guy while he is settling in to his new soil, and how often after that? How much water will I need to give him when I do water him? Does everything else sound like it will be adequate?

I apologize for the poor quality of the pictures. The only digital camera I have is my cell phone, and the lighting does not help.

Thank you to anyone who reads this and to anyone who can answer some or all of my questions. I look forward to raising this little guy, and many more in the years to come. Happy New Year everyone!

as far as temp goes, whatever temperature you live in comfortably, would probably be a-ok for the cactus (thought it can handle quite a bit of heat for a mountain cactus)

as far as watering goes, its best to err on the side of underwatering. worst case scenario you water-stress the cactus, increasing the alks a bit. when it starts to wrinkle, water it. after a while you will get a feel for how long it takes between waterings
(obviously it changes depending how heavily you water it).

idk if it gets subzero in the andes. but i do know that it gets pretty cold there, which is where achuma is from. maybe someone more educated on the climate can chime in. it would be great if you could get them to grow wild there.
but even still just having them in a pot means you can put them out in the summer.
just make sure it get lots and lots of light all year round so they don't get etiolated.
also if you wanted, you could cut the top off one. plant the bottom, then extract one and plant the other.
or do something like that.

or you could get them all to grow bigger and have more to extract (if you buy into that patience being a virtue BS)

Thanks Parshvik!
I'm not sure how possible it would be to grow these guys outdoors year-round. It is not uncommon for the temperature to drop to -20 F several times in the winter in my area. But I have heard that these Trichocereus are pretty resilient, so maybe it would be worth a shot some day.

I was considering cutting the top off of one and just planting the bottom, I think that's what I'll do. For now I'd like to focus more on sharpening my cactus-extracting skills. I would definitely like to grow more cactus some time very soon, but unfortunately I do not have a whole lot of space to work with at the moment. If I did I would probably be stickin' all three of these guys in the dirt!

nice looking cacti and kudos on wanting to keep and grow them out!!

ya man this same thing happened to me. Bought them for extraction, now they are part of a whole new succulent/cacti garden instead. HEH

Thanks folks! Will it still be alright to repot them even though it is winter and they are most likely dormant? I wasn't aware of the "don't repot in the winter" rule before getting these little guys!

I don't think those will grow good under that light. They will get very etiolated. I would let them rest until spring if I were you.

Nice plants by the way.

Thanks! When you say "let them rest", what do you mean? Like just leave them out of soil? I assumed they would rot if I left them out for too long. I also have a nice plant light that I borrowed from my mother. I'm not sure of the specifics on it, but she has used it for getting seedlings started many times and it puts out quite a lot of light.

I believe you just need to leave them in a cool dark place till the season starts back up.

also, NICE BRIDGESII

hostilis i still remember the first time we talked and you said you liked "bridgesii" mainly and i was like WUT? now im like.. I KNOW WHAT YOU MEAN!

Cool, thanks!

I would put them in soil and then just let them chill out around the house, don't water till spring.

That's what I'd do.

And yeah magic. Bridgesii is awesome. Especially bridgesii crests.

Here's a picture of mine.

Wow hostilis! Those are gorgeous!

Low light until spring as well?

I just keep mine away from a bright window. But not complete darkness. That's just what I do. Some people do other things. I think that if you put them under that light they'd get pretty etiolated. Flouro lights are good for seedlings and pereskiopsis, but for adult trichs it doesn't perform very well.

Cool, thanks. I got a nicer plant light for when they wake up in the spring and they're hungry for sunshine. Thanks for all your advice!

They do best with colder temps in winter, between 40-60°f does very well. Bright conditions if possible. Andean winters tend to be cold and wet, but most temperate climate growers keep them dry in winter.

For pot size 8" is very small. More root space equals better growth.

They can take cold down to about 25°f min, with some forms able to survive 15°f, but that is rare.
Best to keep them above 40°f if you want to play it safe.

If using HID lighting aim for 40-50w/sq foot coverage and place as close to the light as possible without overheating, lighting from a diagonal side position works better than overhead.

Thanks! The area I have them in is about 60°F on average. Why is it that diagonal lighting works better than overhead? I'm not doubting you, as I am very inexperienced, I'm just curious what the reason is.

They are columnar cacti, their main photosynthetic tissue is on their sides, not arranged up as in leafy plants. As CAM plants they are going to do a lot of their in-situ photosynthesis in the morning when light is largely horizontal and temps are a bit cooler.

Nice to be seeing you around AKL(cacti guy you)