I don't know how to figure out when to water my houseplants. I read when the top one to 2 inches are dry you should water then. Is this true? Do I let the dirt all or most of the way dry before watering? And what is considered dry toward the bottom? I'm sure if when you squeeze it and it sticks together that would be considered wet enough but if it doesn't stick together but you can tell it still has moisture cause the color etc. But not dry totally like the very top layer do you water then? Are mats in your plant dirt from excess watering? Thank you in advance any tips or ideas will be greatly appreciated :-)
When to Water Houseplants
You ask some very good questions. You are correct in your understanding of the importance of the moisture level all the way through the pot, not just on the surface or the top couple of inches. When you have soil that maintains the moisture level evenly all through its volume, the top of the soil will be a good indicator of the moisture level below. However, not all soil does this. For that reason, it's best to check the moisture level closer to the bottom of the pot, so you can figure out the capabilities of each pot of soil.
The ideal moisture level (or aeration level, if you will) to reach before watering depends in part on the type of plant, and in part on the light level. The general rule is to allow the soil to reach the level where it has enough moisture to stick together when squeezed, but will fall apart readily when lightly touched. It will feel soft and cool. You rarely want the soil to dry completely (possibly only for succulent-type plants in low light) rather you should still be able to feel a faint amount of moisture. A good idea is to test the soil moisture, either with an electronic moisture meter, or a thin wooden dowel or bamboo kebob skewer,which you can insert into the soil then run between your fingers. This article has more information: https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/testing-moisture-in-plants.htm
As for your question about "mats," I'm not sure what you're observing. Fungi growing in the soil can sometimes produce mats; fungi frequently are found in soil that is too wet