Can I encourage Maxillaria tenuifolia to grow from the base?
 

I recently bought a Maxillaria tenuifolia. When I repotted it, I realized that it was previously potted very deep in the medium, and that many of the pseudobulbs covered by the medium were rotting. After removing the rotted pseudobulbs and roots, I ended up with four separate plants, each with a single stack of pseudobulbs.

The plants look a bit weird, and I was wondering if there is any way to encourage them to develop more pseudobulbs at the base, rather than growing vertically? Maybe by cutting the top pseudobulb?

Thank you for your suggestions!

Maxillaria tenufolia may look weird as a young immature plants. But that is how they grow, newer pseudobulbs grow upwards above the older ones, forming clumps of shaggy grass like mounds. The flowers will hide inside the long thin leaves above the pseudobulbs and have that lovely coconut scent. Your plants are fine and will grow into small mounds over time (a few years) or repot them all back into one pot and that will shorten the time some. But either way patience will be needed.
The plant in the photo was only three pseudobulbs when we got it five years ago and looked like yours.

I agree, that's just how they grow, stacking bulbs is their natural habit. They usually start new bulbs mid spring (late April for mine), so hopefully they should start to fill out a bit next year.

However, once your plants get larger you can manipulate that to some degree. If you keep them in small pots, they tend to grow upwards. If you increase the pot size (without overpotting) or mount them they tend to stack a bit less and put out more growths from the base.

This is mine, after 9 years of growth. It started out just like yours.
https://shutterbug.ponzio.net/_data/...ee38151-me.jpg

One more note... there are roots from those "stacked" pseudobulbs that reach all the way down into the medium. So don't remove those brown sheaths - they protect the roots. This "climbing" habit eventually turns into beautiful pendulous growths full of flowers like those of Camille and Selmo, even though the pot looks small by comparison. Let the plants do what they want to do naturally.

Also, these really don't want roots disturbed- The plant would have been better off not being separated, but what's done is done. Now just let the pieces have a chance to establish. Since you have 4 of them, perhaps try mounting one of them, with sphagnum over the rhizome areas.

Here's one that I mounted a couple of years ago. Some nice new growth both at bottom and top.

And just for grins, here's one grown by a friend of mine in southern Orange County, CA (coastal). It is still in its original 4 inch basket (though by now, pretty much guaranteed there is no medium left) The plant is about 4 feet across (actual measurements 44 inches x 30 inches). My friend says "maybe time to repot and divide to make it look better... maybe next year". Don't mess with success...It has been growing that way, outdoors, for about 8 years.

Thank you all for the recommendations. I guess I just have to wait. Looking at your pictures, it's worth the wait...

@Roberta: Many pseudobulbs and roots were rotting. For future reference, do you still believe I should have let them as is?

With these, it is sometimes hard to tell what is actually rotting and what is OK. If pseudobulbs were squishy or smelly, then yes they'd need to be removed. If just black, I'd rinse them and the roots and put in small bark (or even sphagnum in a basket) and let them root. (One big plant is stronger than several little ones) They're weird... roots can look fairly awful and still be supporting the plant while it makes new ones. These things tend to ramble. I have had some success putting them in a bulb pan with well-drained medium, laying the "stack" of pseudobulbs on the medium instead of hanging down, and they can root. But it's in the nature of the species to stack up the growths. Once the plant gets established, what is in the pot becomes pretty irrelevant.

When a big plant is divided, it's common to put some lower pseudobulbs into the pot, especially if there aren't a lot of roots. Since roots run between the pseudobulbs, that means that there are some roots to go into the medium even if there aren't many "free" roots. That, of course, is not a good environment for those pseudobulbs and they may rot at least somewhat, but if the attached roots reach out and continue to hydrate the part above the medium, the plant will establish itself and grow new roots.

It sounds like you did the right thing to me, not everything in orchid growing is always straightforward.

For example Roberta believes in not removing the sheaths, I believe in removing them but I know that in both scenario's they will grow.

I just need to finally show my tenuifolia that is in worst shape. It was a shrivelled mess and the first pseudobulb it grew was so weak it snapped off from seemingly a gust of wind one day, the newest pseudobulb is also very set back and I felt the leaf sheaths were too hard and solid because the plant was so dehydrated to let new roots reach down.

So if you do remove the sheaths this is what happens, notice the old brown roots and notice the new roots forming where I removed the sheaths. The new roots are starting to possibly get a bit dehydrated but that is because I don't have the time to water aerial roots so maybe they would have been better covered but it was only after a year of no root growth and removing the sheaths a little that roots suddenly started growing within weeks. Who knows, I will just add this picture to show what does happen if you remove the old dried leaf sheaths:

PS: I have just checked my other tenuifolia's and they are all in active root producing mode so maybe I got lucky with my timing, you don't want to be ripping new root tips off so now is probably not a good time to go snipping things off, I did it when the plant was seemingly dormant a couple months ago and I would do it for this one again but a healthy tenuifolia with plump pseudobulbs will grow just fine by itself - just adding that as a disclaimer to my method

these are so fun...i think they are super adaptable as i have them in a few mounts and the big on in a 2 gallon bucket of SH...

i have to really agree that leave it alone is the best play and it will "fill out" naturally

These delightful plants have evolved multiple approaches to survival. They will root from a node if they need to... if it roots into medium, those roots that run the length of the plant do their thing (even if they don't look great they're doing their job). But they can also root from the nodes - if they are growing on a tree, they can attach at multiple points. Or if broken or cut, they'll definitely root at that point. So once it gets big, it's the sort of plant that is easy to share with a friend.