I subscribe to several Youtube gardening channels covering gardening and house plant care. However, I have not heard any of these experts recommend using pebbles in the plant saucers to create pebble trays. Since this concept works for me, I thought you might like to try it.
I find it helpful to have each of my house plants sitting in a saucer or tray filled with river rock. Each of my saucers is solid plastic. I fill them with the river rock, and a shallow layer of water results from watering runoff. The layer of river rocks protects the plant’s roots from sitting in water, and the humidity level around the plant increases as the water evaporates.
Note: I prefer “river rocks,” which I purchase from Amazon.
I’ve included the video below to help clarify what I am suggesting.
The saucers filled with a layer of river rocks work because of their simple design (and basic science). The river rocks keep the plant from being wet constantly, and the water in the tray evaporates, rises, and increases the moisture level around the plant.
I choose river rocks because I like how they look, but the type and size of pebbles best for humidity trays can vary. River rocks, gravel, glass, and other small stones that don’t absorb water are preferred.
Let me know if you try adding pebbles to the saucers of your plants and what you think of this suggestion.