Indoor Plants to Purify the Air

Credit: Terry Guscott

Plants such as spider plants, philodendrons, gerbera daisies, figs and chrysanthemums are all excellent air cleaners and oxygen producers. The recommended rate for efficient air exchange is two plants per room, plus a third if ceilings are high.

An average house of 540 square metres requires 15 plants to keep its air filtered properly. As plants do consume some oxygen at nighttime, when they are respiring, it is recommended not to overdo their placement in a room where a sick person is confined.

How to care for indoor plants

Taking care of indoor plants is a fun and nurturing process. After making sure that light and temperature levels are correct, regular watering, feeding and cleaning, plus monitoring for pests and disease, and the odd potting up are all that’s required. Watering is often the biggest concern for tropicals. A good rule is to allow the soil to dry out completely between waterings. Let the water saturate the soil completely to decrease any fertilizer salt buildup. A twice-yearly hosing down will keep leaf surfaces clean, promoting growth and allowing the plant to circulate air more freely. Simply take the plant outside on a warm spring or fall day (in a shady area) and rinse with a shower spray from the garden hose. Gently wipe using a clean soft cloth and allow plant to dry completely before returning inside. Potting up is generally done once every year. You’ll know you need to repot when the roots have filled the pot; watering becomes difficult or the plant continually falls over. Once potted up, water the plant well and use a liquid bone meal to encourage good root development. In order to develop roots, luscious leaves and colourful flowers, all houseplants need to be fed regularly. For an all-purpose organic feed use a liquid fertilizer, such as kelp or fish, every two months, with an additional supplement of liquid bone meal up to twice per year. Insects can often be a problem with houseplants, particularly in winter when the air is dry. To control scale insects, simply rub the scales with cotton swabs dipped in rubbing alcohol. Soft-bodied insects like aphids and whiteflies can be safely treated with an insecticidal soap. Beneficial insects are an excellent way to control fungus gnats or spider mites. With all products be sure to follow the directions closely.