Consider the human body in extremely dry conditions: the skin feels irritated and dry; the hair becomes brittle; and the lips become cracked and sore. It is no different for plants – just because they are getting the proper amount of light, air, water, and food does not guarantee they will flourish in a home setting. In fact, improper levels of humidity can cause just as much damage as anything else.
A lack of humidity is the biggest problem during the winter season, thanks to radiators and central heating systems. Principles of science indicate that cool air is much more able to hold moisture than hot air – think about the dampness of the morning compared to the heat of the midday. Heating systems, especially when they are cranking out hot air during the winter months, heat up the environment so that the air loses its humidity. This can cause big problems for plants, which rely on drawing in moisture from the air.
There are several signs that indicate your plants are suffering from a lack of proper humidity. The most apparent symptom is the curling and browning of the edges of leaves. Other signs include yellowing and wilting of leaves as well as stunted flowering. If you suspect that your plant is suffering from dry air, you have several options available to you. The first is to use a humidifier or try and find a more humid location – consider the bathroom or the kitchen if you have space and don’t mind plants in those rooms. Moving plants around the house is not always the best solution, though, even if you have the space to accomplish it. Plants become accustomed to a spot in the house, and frequently moving them around, especially if the light and air flow is different, can send a plant into shock, creating even more problems.
A better solution is to use a spray bottle to mist your plant on a regular basis. This requires more work, but then again, your houseplants deserve your attention. To do this get any sort of spray bottle; these can be designed for plants or general cleaning tasks. Fill the bottle with lukewarm water, and spray thoroughly all over the plant. Do not overspray – when the leaves are covered with small drops you are finished. Make sure to get all the leaves, and don’t spray when the sun is directly on the plant, as the water can intensify the sun’s rays, leading to possible leaf damage. If you can, spray in the morning, so that as the day grows warmer and drier the plant will retain its humidity, but will be dry when the night falls and the cool air returns. An added benefit of frequent misting is that it helps clean and protect the leaves from dust.
Another option for controlling humidity is by grouping plants together. In the way animals group together during the cold months to use each other’s body heat, the plants use each other’s moisture in a group setting to retain a more humid environment. If you wish to group plants together, the best way to accomplish this is with a pebble tray. Although most garden centers sell specialized pebble trays, any plastic tray large enough to hold your plants should do fine – just make sure it doesn’t leak. The tray should be high enough to hold an inch or two of pebbles with enough room left over so no water spills over the edge. Pour the pebbles into the tray, and fill the tray with enough water so that the pebbles are damp but not covered by the water. Set the plants on the pebble surface, making sure there is enough space for the leaves and branches to extend properly. If it is too crowded, make another tray. Make sure that the pebbles stay damp all the time – you may be surprised at how often the water evaporates.
Although too little humidity is the biggest concern with the air environment, it is possible for too much humidity to exist, especially in damp climates or in a room such as a basement. Signs that this may be the case include the appearance of a grayish mold on the leaves and flowers and the development of brown rot on the leaf stems. If you suspect that the plant is getting too much humidity, reduce any misting you may have been doing and consider a dehumidifier.
