We spend most of our lives (especially here in Florida) trying to get rid of humidity. Our cars work hard to dry the air that cools us in the summer and so do the air conditioning systems in our homes. When air is really humid, it can be very uncomfortable and make hot temperatures downright miserable.
As much as we feel more comfortable in drier air, many plants need humid air to really thrive. Sure, there are plenty of plants that like arid, desert-like climates, like many cactus and succulents. When it comes to houseplants, the majority of them are native to humid environments. Picture the rainforests of South America or the jungles in Asia. Lots of shade from the thick canopy overhead and constant rain and moisture creating very high humidity levels. That's where a lot of your favorite houseplants grew natively - things like philodendrons, monstera, calathea and even pothos. None of those are plants you would find growing naturally if you went walking through a desert.
Since we like the comfort of dry air, our home environment where we are growing our plants is often drier than plants prefer. You've seen brown tips on your calathea before, right? That's a sign that there isn't enough humidity in the air. You know that plants take in carbon dioxide and release oxygen into the air. During that process, moisture is also released into the air. When the air around a plant is extremely dry, more water is lost in that process than the plant can replace and since leaf tips are the last part of the plant to receive water, when there isn't enough, they turn brown.
Fortunately, you can enjoy a comfortable environment inside and keep your plants happy. Notice that the ideal level of humidity is between 40 and 60%. You don't need to turn your house into a rainforest, just make sure the area around your plants is a little more humid than the rest of your home and you can do it in a few simple ways:
1. Cluster plants together. When plants are near each other, the moisture released by one can be taken up by another and they will help each other out.
2. Use a humidity tray. That's fancier than it sounds. Any saucer or tray can be used. Just fill it with a layer of pebbles and then add water until the water level is about halfway up the pebbles. Set plants on top and as the water in the tray evaporates, it will increase the humidity in the area of your plants.
3. Mist plants occasionally. Keep a little water spritzer nearby and a few times a week, give the area around your plants a little misting. It doesn't seem like this would do much, but it gives plants a chance to move water into all of its stems and leaves, reducing the number of browning tips.
4. Use a humidifier. There are lots of options for indoor humidifiers, from small to large. If you have a large plant collection, a dedicated room for your plants or if you happen to live in an area where the humidity is naturally low, you may want something that keeps the humidity level up for you.
Of course, be sure to keep plants away from drafty areas in your house or from the air vents to heaters and cooling systems. Air moving across the surface of the leaves of plants will remove water from a plant even faster. So, there you have it, a little bit about humidity.