Use these simple hygrometers to keep an eye on your relative humidity. Veronica uses them to know when to water, because plants will maintain moisture levels in the air when they have enough water. Notice a dip? It could be time to water!
Place these hygrometers in various places around your home to keep an eye on humidity levels and temperature in your home. Want to get fancy? Keep a diary with these measurements (or a spreadsheet! with a graph! get nerdy!) and see if you notice a correlation between temperature, even humidity (which points to even watering practices), and growth!
For information about how to interpret relative humidity, please listen to The Houseplant Coach Podcast episode 7.