|I have a Calathea rotundifolia. It is in a constant water pot (water in the bottom with a suspended clay pot) The soil is what is recomended by the pot maker. (Potting soil with ectra vermiculite) All the leaves have brown, dried parts on the edge. It is not in sunlight. What an I doing wrong?|
|Since the browning is along the edges, I would first guess that the air is not humid enough. You could try it placing it on a pebble and water tray to increase the humidity in the immediate area, also make sure it is not in a draft.
This plant likes an evenly moist yet well drained soil. Root damage sometimes shows up as foliage problems. My next thought is that the soil may not be well drained enough, meaning that it is not holding enough air to keep the roots healthy. Without knowing what type of soil mix you started with, it is difficult to say one way or the other on that however. A soilless mix with extra vermiculite should be well aerated, but a mineral soil based mix might be too heavy and saturated.
Next, do make sure that the soil is pulling enough moisture through the wicking action so that the plant is receiving enough water.
You might check too that the roots have spread into the special potting mix you used, rather than staying in the original rootball from the store. If they have not grown outward you could try to tease some loose and untwine them and direct them into the new soil. That way they will not be crowded and stunt the plant and possibly prevent it from absorbing the available water.
Make sure you are not overfertilizing as this can cause foliage symptoms as well. And if your water has extra minerals in it or is heavily treated or is run through a water softener system you might try using rain water instead of tap water in the reservoir.
Last but not least, make sure the plant is not in a cold location, it really prefers warm household temperatures. I hope this helps!