Pebble Tray
Humidity is often a crucial part of indoor plant care. Unfortunately symptoms are very similar to those of under watering or too much light, such as dry crispy tips and edges of leaves, or leaves curling inward and not opening over time. However, if you are giving the plant it's preferred level of water and it still experiences these symptoms your plant would likely prefer a more humid environment. Around the Bay Area humidity is relatively high, so if you live in an older house this likely won't be a problem. We frequently see low humidity in modern, buildings that are sealed up tight to conserve energy and when radiators or furnaces kick on in the winter. Remember that this will vary by room; bathrooms and kitchens, especially near water fixtures, have increased humidity. Often a quick fix is to swap the plant to one of these areas, assuming the light is adequate.
Common houseplants that appreciate a high level of humidity include ferns, orchids, maranta, calathea, bromeliads, alocasia, colocasia, hypoestes, caladium, aglaonema, dieffenbachia, spathiphyllum, philodendron, monstera, pothos, tillandsia, begonias, ctenanthe, carnivores, most palms and anthurium.
By far the best way to increase humidity is by adding a humidifier. Other great tricks are frequently spritzing with a spray bottle on a fine mist setting or placing a dish of water on your radiator. You can also make a pebble tray, though their effectiveness is debated. To create a pebble tray choose a saucer that will hold water without wicking (so no terracotta saucers on wooden surfaces) and fill it with medium sized gravel. Remember the wider the saucer the more it will increase the humidity, so it should go at an inch beyond a small pot or several inches beyond a large pot. Place your plant on top of the gravel, being sure that when you fill the saucer the plant will remain above the water level. Theoretically, as the water evaporates from your pebble tray it creates a bubble of increased humidity around the plant. Just top up your tray when the water is almost gone. If you have positive or negative personal experience with pebble treys we'd love to hear from you!