Once you have battened down your outdoor gardens for the season, you might wish for a little rest from tending plants. But if your green thumb starts to itch you may want to think about getting a few houseplants. Houseplants are a relatively easy and inexpensive way to add color and life to your interior landscape. Some basic plant care applies to all houseplants; a few might require some special care or growing conditions… Most houseplants are tropical in nature and in their natural habitat they receive abundant light and water, but they also grow in high humidity. In the winter Minnesota homes are generally very dry, so care must be taken to ensure that houseplants receive adequate moisture; water your houseplants when the top ½ inch of soil becomes dry. African violets should be watered as soon as the soil surface is dry.
In addition to perking up our home décor, plants can also fight indoor pollution. NASA conducted extensive research to determine ways that the air quality could be maintained in the International Space Station so that it would be safe for habitation for extended periods of time. Over the course of two years NASA scientists studied 19 plant species and discovered that they filtered harmful chemicals from the air. In addition to removing carbon dioxide and adding oxygen, potted and blooming plants remove many harmful gasses from the air during photosynthesis. In addition, plants absorb benzene, formaldehyde and trichloroethylene toxins and render them harmless in the soil.
Newly built homes are most in need of “air purification” because many new construction materials “off gas” pollutants. In addition many newer homes are tightly insulated for energy efficiency allowing limited fresh air exchange. These two factors combined produce what were referred to as “sick houses.” Most of the homes in Camden were built prior to the 1960s, so few of us are in danger of living in a sick house, but remodeling and home additions may introduce materials that may ‘off gas’ pollutants, including synthetic carpeting and fabrics, laminated counter tops and plastic-coated wallpaper. Also in response to the energy crisis of the ‘70s many homes were over insulated and tightened up, so we may benefit from the air purification of houseplants.
NASA researchers recommend 15-18 good-sized houseplants in 6-8” diameter containers to improve the air quality in an 1800 square foot house. This may seem like more plants than you want to care for but any number will help to improve indoor air. Plants involved in the NASA research include many of the most familiar houseplants which do not any need highly specialized care. In fact most of these plants grow naturally in the understory of the tropical forests where they receive filtered light through the branches of taller trees, similar to the filtered light they receive in our homes. Because their leaves are used to this kind of light they are highly efficient photosynthesizers, which allows them to process air gasses efficiently.
One houseplant that you might consider for your interior décor and to help with air purification is a Boston fern. It’s the old-fashioned fern that many of our grandmothers kept as houseplants and it is characterized by arching ruffled fronds. For many years I suffered under the misconception that since the ferns that grow in our Minnesota woods grow in fairly shady conditions, a Boston fern would thrive in a dimly lit corner of a bedroom or bathroom. Wrong. The tropical ferns we use as houseplants require plenty of medium light. From November through February, they do well if placed near a west or south facing window; not too close so they don’t get any cold drafts. After February the increased sun intensity may burn the delicate foliage, so move them to an east window. Keep the soil evenly moist. When the top of the soil is dry, water thoroughly until water comes out of the drain holes in the bottom of the pot. After a few minutes dump off the excess water in the saucer. With proper watering and adequate light you should have a fern growing for many years.
If you are looking for plants that require less light than ferns you might do well with a pothos or peace lily plant. Both are members of the aroid family. In the tropics they are called ‘understory plants,’ which means they grow in dappled shade under the high canopy of trees. Both plants will survive in a north window or a room where there is enough sunlight to easily read the newspaper most of the day. The pothos is a vine with glossy green leaves. An additional advantage of a pothos is that you can cut off part of the vine and “root” it in water.
Palms can be a dramatic addition to any room, but dimly lit corners are not for them. Even the most shade tolerant need fairly bright indirect sunlight. The best shade tolerant variety is the parlor palm (Chamedorea elegans) and they range in height from 8” to 4 to 6.’ One of the most common problems with palms is browning leaf tips. This is usually a result of improper fertilizing and watering. The soil should be kept moist but well drained. Fertilize only when the plant is actively growing, late winter through early autumn. Over fertilizing results in a buildup of fertilizer salts in the soil which result in “burnt” leaf tips, especially if the soil is allowed to dry out. A pest to watch for on palms (and other house plants) is spider mites. Keep your foliage clean; dusty foliage is an attractive habitat for spider mites.
Just a few houseplants can not only brighten your interior landscape but can also provide you with a healthy atmosphere.