Pilea Depressa (Baby Tears) Leaf Damage
Hello, Some leaves on my pilea depressa have white/brown spots. These white spots are not ON the leaves, they are IN the leaves. There are not many. But there are enough for me to be concerned! Is it powdery mildew? Can mold grow in leaves? Because, again, it's not on them, it is right under the top transluscent layer of the fleshy leaves. There are also some brown edging/damage on some leaves. I don't know if they are connected. My routine/set up: it is in a pot that supposedly has drainage. It has well draining soil from a regular potting soil mix. I was too worried that I have been overwatering it so I've been letting it dry out before I give it a good soak. It is placed on a northwest facing windowsill. Admittedly, it is near my heater. I just bought a mister to mist the leaves, as I hear they like humidity especially if they are near the heater. Is there mold? Heat damage? From being near the heater or too much sun? Have I been over-/under-watering? I apologize if I sound frantic. I just love this plant so much! Thank you for all of your help!!
The white dot looks like edema, not an insect or disease. https://extension.umd.edu/hgic/topics/edema-houseplants
Although baby tears do not commonly have problems with edema, it is probably related to the changes in the waterings routine--extremes of moisture levels.
We do not see how this pot has good drainage, as that refers to pots with drainage holes, which this pot doesn't seem to have. A pot with a drainage hole in the bottom, sitting in a saucer, allows you to see when the soil is saturated, as the excess water will drain into the saucer. We'd recommend that you repot this plant into a new pot. The water in the saucer can evaporate around the the plant, which helps increase humidity a bit, too.
Baby tears should always be in moist, though not standing water/soggy, soil. The surface can be allowed to dry out a bit, but about 1/2" down or so it should stay and feel moist. Like many houseplants, baby tears require less water in the winter, when they are growing more slowly. So, they will require less water then. This is why it is better to not water the same amount all year on a rigid schedule.
The brown edges may, indeed, indicate that at one time you were overwatering and rotting the roots. Again, repotting into a pot with drainage holes should eliminate the problem of roots sitting in water. https://extension.umd.edu/hgic/topics/overwatered-houseplants