My TBM Is Weird and Has No Off Switch
Seven segments and counting — and honestly, I didn't see nine coming this fast.
This particular TBM has been a fun one to watch over the past couple of weeks, putting out new growth at a pace I wasn't quite expecting. I picked it up at Walmart back in February 2025 — a Costa Farms plant, single segment, sitting quietly in a tiny plastic pot and looking lonely. I knew someone else would snatch it up if I didn't. Fast forward to now and that original segment is the anchor, sitting dead center in the pot, and everything else has erupted outward from it like the plant is on a mission to prove its worth.
That center segment is where it all started — one quiet little TBM from the Walmart garden section that apparently had a lot of opinions about its future.
So what even is a TBM? Trichocereus bridgesii monstrose — the monstrose mutation of a bridgesii cactus. Instead of one tidy growing point, the plant develops multiple, and those growing points don't follow any predictable pattern. There's no blueprint. The result is this wonderful, weird, sprawling thing that looks different every time you check on it. They're also commonly called penis cacti, which — once you've seen one — you'll understand immediately and never be able to unsee. I mean the cactus. Just to be clear. There are actually two forms — Type A, which grows taller and more columnar, and Type B, which is the shorter, more compact form that pushes out segments in every direction. Mine is a Type B, which should be obvious from the photos. Worth mentioning too — TBM-C is a completely separate animal, a crested form of the bridgesii that grows in a wavy, weird, all-over-the-place pattern rather than multiple segments. Different look, different growth habit, different conversation entirely — and one I happen to have a few of. I've already covered some of them in a recent post, and a few more will be showing up here soon.
This is still a young plant — not even two years old yet. There are collectors out there with TBMs that have been growing for years, sporting dozens or even hundreds of segments. Nine feels exciting right now, and it should, but we're just getting started. Of the four I picked up back in February 2025, this is the only one showing any hint of variegation — nothing dramatic, just a slightly different look to the skin that catches your eye once you know to look for it. It's a subtle thing, but it gives this particular plant a little extra character.
I went from seven segments to nine in ten days. Two new pups pushed through in mid-August and I caught both of them right at the moment they were just starting to break the surface. The one on the left had a three or four day head start on the other, and it shows. I photographed them every day — mostly in the mornings so I'd have a clean 24-hour window of comparison, though I'll admit a couple of evenings slipped in there when life happened. Watching something go from a tiny nub barely breaking skin to a full inch of cactus in just over a week is one of those things that makes this hobby genuinely exciting.
Ten days. Two determined pups — one with a bit of a head start on the other. A couple of these frames were shot at sunset instead of morning — you'll know which ones because the light looks better than I deserve credit for.
What's funny is that this one is actually the slowest of the four TBMs I picked up around the same time. The other three are pushing ahead faster, which I'll get into in a future post. But there's something about this particular plant — maybe it's the slight variegation, maybe it's just its personality — that keeps it interesting in a different way. It's not racing. It's just doing its own thing, in its own order, and occasionally doubling its segment count when I'm not paying close enough attention. The slight variegation may be the reason it’s the slow poke of the four. Who knows.
Nine segments now. I'm genuinely curious what it'll be by next spring. Heck, I’m curious to know what it will look like next month.
