How can I raise humidity quickly?

Running a humidifier is the best way to quickly and reliably add humidity to the air around your plants. But if you don't have a humidifier in the house and your plants need moisture right away, mist them with a fine spray bottle.

Does a bowl of water increase humidity?

Yes, placing a bowl of water near your plant will increase the humidity slightly as the water evaporates. This is a very similar principle to a pebble humidity tray, but a bowl is the less effective of the two. Since the water evaporates straight upward, having the water underneath your plant (like a humidity tray) exposes more leaves to moisture as opposed to a bowl that's beside your plant.

Is too much humidity bad for plants?

It depends on the type of plant you have. Plants that are native to tropical regions of the world thrive in humidity up to 80%. However, for plants that prefer drier conditions, overly moist air can lead to problems with fungus or mildew growth or mushy, discolored leaves. Also, certain insects, like fungus gnats, flourish in constantly-damp environments.