A couple weeks ago, I noticed that the plant looked a bit blah, even though the plants in the tray had been watered that week. I pulled the entire tray off the stand and put it in isolation until I had more time to investigate.
Overall, the plant had general malaise. It appeared to be overwatered and over-potted, and it seemed wobbly in the soil. The leaves were limp , so something was obviously restricting water to the leaves.
1. It can be soil mealy bugs, which destroy the roots until the plant simply has none left. If you’ve ever had SMB's, you really never forget the signs. Unpotted, the root/soil ball shows webbing and tiny white particles. You think it’s perlite, but then they move. While the process can be tedious, SMB’s can be eradicated and plants can often be saved if caught early enough.
2. The plant is suffering from root rot. This happens when young or poorly-rooted plants are kept in pots that are too large and/or are over-watered. If water sits in the soil for prolonged periods of time, there aren’t enough roots to utilize that water. The roots drown, and the plant cannot take up water or nutrients.
3. The plant is suffering from a different, but related type of rot: stem rot. This happens for basically the same reasons that root rot happens. They have the same cause, and actually stem rot usually begins as root rot and then migrates up the main stem. Other causes for stem rot include potting a plant too deeply in the pot.
So, with these possibilities in mind, I began the process of investigating this plant.
In my experience, stem rot is sneaky, because it tends to reveal itself only when it’s almost too late. It’s generally not the obvious, overnight collapsing caused from shock, trauma or serious pest problem. Although damaged, the plant may not appear visually symptomatic unless scrutinized, so the problem is easy to miss unless you are handling and inspecting each plant daily. Sometimes plants will appear normal until they are touched, and then you realize that each leaf stays in place instead of bouncing back again. Also, the entire crown is often just sitting on top of the soil without purchase of roots, with its limp leaves resting on the rim of the pot.
With this particular plant, I stripped away all but a crown of leaves. Then, I cut the main stem down to about ¼ inch and held it upside down to inspect the inner tissue.
Keep these things in mind to avoid stem and root rot. The next time you have a plant that doesn’t have a lot of roots when you repot it, be careful not to over water it, and be aware of the signs of root and stem rot. Try to keep your plants away from the lowest and coldest part of your shelves, as cold soil tends to speed the process of rot. Handle and inspect plants regularly when watering and always isolate new plants and any old plants that show odd symptoms. If you suspect any plant as having stem or root rot, do not hesitate to pull it out of the pot and take action. It is usually the only way to save a plant.