Raising Humidity: How To Increase Humidity For Houseplant

Before you bring new houseplants into your home, they probably spent weeks or even months in a warm, humid greenhouse. Compared to a greenhouse environment, the conditions inside most homes are quite dry, especially in winter when the furnace is running. For this reason, it is important that you learn and practice appropriate humidity houseplant care to ensure the longevity and health of your beloved plants.
Humidity for Houseplants Indoor plants need humidity levels between 40 and 60 percent, and suffer from stress when the humidity for houseplants is outside that range. If you don’t have a hygrometer to measure the humidity inside your home, watch your houseplants for signs of stress. 

Consider raising humidity levels when your houseplants exhibit these symptoms: 

  • Leaves develop brown edges. 
  • Plants begin to wilt. 
  • Flower buds fail to develop or drop from the plant before they open. 
  • Flowers shrivel soon after opening.

How to Increase Humidity

Increasing humidity levels in the home will prove beneficial in the long run. Before undertaking any of these, make sure your plant is of a type that requires higher humidity. If you know where it's from originally, that's a good clue. Once you've determined that higher humidity is warranted, any of the following ideas can be used to increase humidity:

  • Group your plants. Plants release moisture through their leaves in a process called transpiration. By grouping plants together, you create a more humid microclimate in your growing area that will benefit all the plants. It's also a good idea to keep plants with similar humidity requirements near each other. For example, if aroids are your passion, group all your aroids in one place where their more rapid transpiration rates will create higher ambient humidity in the growing area. This, however, would not be an ideal place for a succulent or cactus, both of which require lower humidity levels.
  • Put the plants in trays with pebbles. This is a popular way to raise humidity immediately around your plants. Use clean trays and put at least an inch of pebbles in each tray, then set the pots on the pebbles. Fill the tray with water halfway up the pebbles, but don't let the pots sit directly in water, which will encourage root rot and plant collapse. Every time you flush your plants, make sure to empty and rinse the tray. This will ensure that the tray doesn't become a breeding ground for insects and it will reduce the concentration of fertilizer salts that have accumulated in the tray.
  • Mist your plants. This is another popular method to increase humidity. Keep a misting bottle filled with clean water near your growing area and spray the plants every so often. Misting is especially helpful at the beginning of the winter season when the humidity drops rapidly with the temperature. However, some plants should never be misted, including any plants with hairy or velvety leaves, such as African violets. Misting these plants encourages diseases that can be fatal because the “hair” on the leaves holds water in place, encouraging diseases and leaving unsightly spots on the foliage.
  • Use a humidifier. Humidifiers will raise the humidity in the whole room, but they are an excellent way to increase humidity in a growing environment.
  • Use a terrarium. If you're growing plants that cannot be satisfied no matter what you try, consider switching to terrariums. A terrarium is an enclosed environment with some soil and a few small plants. The system is sealed, so the plants take up moisture, "exhale" it through transpiration, only to then have the moisture gather on the walls of the terrarium and fall back into the growing media much like the water cycle in the outdoors. Terrariums are perfect for smaller plants that require higher humidity and temperatures.

How to Decrease Humidity

Rooms where you use a lot of water are often very humid. If a plant in a kitchen, bathroom, or laundry room shows symptoms of stress from high humidity, move it to another part of the house. On the other hand, plants that show symptoms of low humidity will benefit from spending some time in the humid parts of your house. Most houseplants originate from humid jungle environments, and moisture in the air is essential for their health. 

Here are some quick signs to look for to see if your room is getting too humid:

  • Unwanted biological growth like bud molds, powdery mildews, etc.
  • Too much moisture buildup will welcome bud rotting or flower rotting, which can’t be seen until you’re in the harvesting stage.  
  • Plants love humid air while they’re tender, and less humid air while they’re mature. If it still remains in high humidity while grown up, it will prohibit the growth rate and health quality of the plants.    
You’ll be surprised at the way your plant will respond to adjustments in humidity, and you’ll have the satisfaction of enjoying lush, thriving plants. If your room is too humid, try relocating your houseplant.