Have you considered humidity and how it affects your houseplants? Some have argued that humidity isn’t a huge factor when taking of plants, but I beg to differ. I think the humidity level is important for your plants. Most of our houseplants are from rainforests where the humidity is literally dripping from the trees, so of course, our houseplants want elevated humidity, which isn’t always easy to come by in our homes.
Humidity in our homes
Humidity is water vapor in the air. The air can hold more water at higher temperatures. Approximately 35% humidity and under is considered low humidity in a home, 35-70% medium humidity, and 70% or higher is considered high humidity. If we can keep our homes at or above 50%, we are going to feel better and our plants will be happier. With our air conditioners going in the summer and heaters in the winter, it is hard to keep that amount of humidity in the air.
Each plant is different
Every plant needs a different level of humidity. Obviously, plants that grow in arid places such as cacti and other succulents won’t need as much as humidity as plants that grow in rainforests. (Remember, there are rainforest cacti, such as holiday cactus, so the low humidity doesn’t apply to them.) Also, thicker leaved plants need less humidity than thinner leaved plants. The fittonia and maidenhair fern below are both plants that have thin leaves and wilt at the first hint of drying out. If they were in a humid environment, however, they could handle drying out a bit.Read here about a fern that is more forgiving of low humidity.
Transpiration is happening in plants almost continuously and is a little like our sweating. Water is transpiring through its stomata as it photosynthesizes. There are even plants that only do that at night to conserve water. The drier the atmosphere around a plant, the more it transpires. This process is natural and what a plant does, but if it doesn’t have sufficient water in the potting medium to be drawn up into the plant to transpire, damage will occur. This may show up as brown edges on the leaf, brown tips, and could result in leaf loss. Plants will need water more often in a drier/less humid environment.
High humidity areas in the home
Where there is water being used more often is where the highest humidity in the house will be. These rooms include the kitchen, bathrooms, basements, and laundry room. Humidity is higher in these places, but if they don’t have windows or some sort of electric lights, plants will not live there. So many people want to put a plant in the bathroom and that is a good idea as long as you have light. It doesn’t matter how high the humidity is if there is no light for the plant to make food with.
Low humidity reactions
How will you know if your plant doesn’t have sufficient humidity? The plant may show signs of leaf curl, brown patches, drying up, flower buds don’t open fully (called blasting), and flowers fade faster. It could also have smaller new leaves, drop new and old leaves, and just not look as healthy as it should. It could also be attacked by spider mites, a pest that loves plants that are suffering from a lack of humidity.
Raising the humidity
How do you raise the humidity? Create a microclimate by grouping all your plants together. As they are all transpiring, they will rais the humidity in the immediate area. Use a pebble tray to raise the humidity around your plant as the water evaporates from the pebbles. Use a humidifier. There are lots of small ones that can be used in the vicinity of your plants or a whole-house humidifier can be added to your furnace.
Too High Humidity
On the other end of the spectrum, plants can suffer from too much humidity. This could show up as powdery mildew or botrytis, both of which will kill your plants if not taken care of.
There are some plants that will only do well in an enclosed terrarium, though an open terrarium also raises the humidity around the plants.
If you do set up a terrarium, in the first few weeks, check it every day to make sure there isn’t too much condensation on the glass. This can lead to diseases because the humidity is TOO high. Tip the lid or remove it for a while to let the extra moisture out. Eventually, there will be a happy medium adn you can leave the lid on.
I hope this helps you with humidity and your houseplants, especially as the temperatures drop and the furnace kicks on, removing every vestige of humidity from the house. Your skin will let you know when the humidity is low. I may have already had the furnace running a couple of times this past week. Shhhhh….don’t tell my husband. He likes to wait as long as possible before the heater is turned on.
Have a great week my plant friends and do your houseplants a favor and give them some extra humidity!