In order to create a garden full of healthy plants, you need to understand your environment – indoors and out. True, indoor climates are generally more constant than the outdoors, but atmospheric and light issues still play an important role in growing houseplants. What grows well at your friend’s house might not do so well in yours, because every house is different – and indoor conditions can even vary from room to room and season to season. You need to consider a few factors in order for your houseplants to thrive, including relative humidity, air circulation, temperature and lighting.
In general, flowering plants prefer bright light, while green foliage plants can adapt to the filtered sun or partial shade found in the corners of a room or away from its windows.
Photo Credit: ©2002 Dolezal Publishing/John M. Rickard
Even though misting doesn’t replace the need for humidity in a room, make misting a regular part of your houseplant care routine for those plants that prefer high-humidity environments.
Photo Credit: ©2002 Dolezal Publishing/John M. Rickard
Air circulation affects the health of your houseplants. Because the air from heat and air-conditioning registers is often drying, it’s a good idea to move your plants away from floor and ceiling vents.
Photo Credit: ©2002 Dolezal Publishing/John M. Rickard
Snowball cactus naturally grows in hot and arid conditions with sparse rainfall – so it makes a nice houseplant.
Photo Credit: ©2002 Dolezal Publishing/John M. Rickard
Humidity
Most homes tend to be dry, but many popular houseplants do best with a little extra humidity. Even when other environmental factors are ideal, plants that are challenged by low atmospheric humidity will likely have sluggish growth, yellowing leaves or brown tips, leaf curling and flower drop.
To give your plants a good fighting chance, learn the particular humidity needs of your plants and become aware of the available humidity in your home. Part of this has to do with where you live: Indoor air humidity in South Carolina, for example, is generally going to be higher than in a home in Arizona or Quebec. The season also affects moisture levels. While Minnesota and Ontario summers may be fairly moist, heated rooms in winter can become very dry. Air-conditioning tends to reduce humidity, too. And air moisture levels may vary greatly from one area of the house to another. Rooms with water – kitchens and bathrooms, laundry rooms and basements – are usually the most humid parts of a home and are good for growing houseplants. And the more plants you have grouped into a room, the more humid the air will be.
In general, houseplants require at least 40 percent humidity. You can test the moisture level of the air in your home with a hygrometer, an easy-to-use instrument that can be found at some nurseries and hardware stores and through direct merchants. Get a good overall representative reading by testing the air in the room as a whole, and then check the air close to a plant. While the humidity nearest the plant is your most crucial number, remember that overall humidity in a room will still affect the plant.
When higher humidity is needed, you can raise it with a variety of techniques: misting, grouping plants, mulching, creating a humidity tray (a tray filled with pebbles and water) or even running a humidifier near your plants or placing them adjacent to an indoor fountain.
Air circulation
Plants need fresh air to prevent diseases and insect infestations. In many homes, there’s actually enough air circulation created just by family movement or with the opening and closing of doors. (The amount of air movement required is minimal – plant foliage dries out in overly drafty areas.) If your plants seem to show symptoms of stagnant air, which may include developing fungal diseases, try moving them to a location with better air circulation.
Temperature
Fortunately, if you feel comfortable in your home, most plants will do fine. The average houseplant requires a temperature of 65-75 degrees F. Certain plants, however, need periods with a change in temp. flowering cacti, various orchids and cyclamen, for example, require winter temperatures of 50-65 degrees F. For these, seek out cooler spots in your home, which include windows that receive little direct sunlight (especially between the curtains and windows), unheated rooms, basements or locations close to the floor. Avoid hot spots – areas near stoves, ovens, radiators, heating ducts, television sets and high perches.
The opposite goes for plants that require warm conditions to thrive, like wax begonia, lipstick plant and ponytail palm. You can simply gauge the temperature highs and lows in your home with a thermometer. Take readings in a room at different points in time to obtain valuable care information, informally noting the data for future reference.
Lighting
Like temperature and humidity, lighting varies throughout your home. The closer you can match a plant with its light requirements, the more successful you’ll be in growing houseplants. Generally, fruiting and blooming houseplants need more light than those with solid green foliage, as do plants with variegated foliage. A plant’s location in the home will determine the light it receives. An unobstructed window that gets direct sunlight most of the day, for example, will be much brighter than one on the other side of the house. Windows to the east can be counted on for good morning light. Even bright rooms usually have dimmer areas, often located near the sides of the windows and in opposite corners.
Keep in mind that light varies with the seasons, changing with the position of the sun. Consider the different light levels around your home and then match the light in each location with your particular plant needs.
When sufficient natural light is unavailable for the type of plants you want to grow, you can use supplemental lighting. There are several types of lighting options available, including fluorescent lighting, “grow lights” and High Intensity Discharge light systems (HID). When using artificial lighting, attempt to simulate daylight by giving plants regular periods of light and dark. Most plants do best with 12-16 hours of light per day. If necessary, use a timer to control the lights so that they provide your plants with the proper number of hours per day. Also educate yourself on how close you should position the lamps to each plant. This will vary according to the plant and the type of lighting system you have. (It can range from 6-48 inches.) After placing your lights, monitor your plants carefully for the first several weeks and adjust as needed.
While your houseplants are spared the exposure to extreme heat, cold, wind, rain or snow, they’re still affected by the indoor climate you provide. Remember, every room of your home contains mixed growing conditions, each suited to different houseplants’ needs. The trick is to provide the best conditions for each plant – and then watch your indoor garden grow!
