Hi, Andrew - Please tell us more about your watering habits.

If you have been keeping the soil continually moist or have been watering when the top inch or two of the soil gets dry, it's likely you've "watered it to death" and the pathogen is any one of the several damping-off family of fungi.

Too much water and not enough air in the root zone sets the stage for a weakened plant (in terms of its natural defenses, which are directly related to the plant's metabolic rate) and fungal infections.

Ponytail palm is such a durable plant, it's often erroneously suggested they thrive on neglect. They thrive on the type of care that ensures cultural conditions are in the sweet spot and not near or beyond the limits they're programmed (genetically) to tolerate. While they might survive long periods of neglect that leads to the soil becoming completely dry, they don't appreciate that type of treatment. Still, if you had to choose between trying to keep the soil continually moist or allowing the soil to go completely dry before the next watering, you should favor the later. They can "tolerate" being too dry, but cannot tolerate being too wet. Also, it's a plant that appreciates all the sun you can give it, but don't think that its present low light location is a part of your plant's demise.

Al

I have watered it once every 2-3 weeks. @Matt z5b - Greenhouse 10a please see attached for the scratched stem.

I appreciate the thoughtful feedback. @tapla (mid-Michigan, USDA z5b-6a)

I'm sorry to say but with that kind of hole appearing in the caudex, I think your plant is beyond redemption. That is a clear indication of a rot, most likely caused by over watering or an excessively water retentive potting soil, as previously mentioned.

That's what I believe, too. Sorry .......

Al

Take the plant back to where you bought it (2 months old - hopefully they have a policy to replace it within X months of buying it). You can usually buy a small pot of 3 or more bulbous seedlings for a few dollars or at least I have in the past.