Indoor plants can lighten up a room, refresh the smell of a home and even provide a natural air filter. Giving fresh flowers or a potted plant to someone shut in due to illness has been a long-standing tradition. Even with all the natural beauty, health benefits and good intentions, there are disadvantages and drawbacks to raising and keeping indoor plants.
NASA studied the purifying quality of houseplants and found "research has shown that many common houseplants can clean air of toxic gases." However, if you suffer from allergies due to pollen or have trouble with the smell of perfume, indoor plants can cause more harm than good. When you set a houseplant in your home, you are bringing the allergens inside with you. Harboring plants indoors creates a concentrated area for pollen to take hold. While over-the-counter medications have been designed to minimize difficulty with household allergies, this problem can be solved less expensively by consulting a floristry professional and identifying plants that do not cause allergic reactions
Toxic Black Mold
The majority of houseplants require a good deal of water and are moist most of the time. While these conditions are ideal for the plant, they are also the ideal conditions for toxic black mold. Toxic black mold grows from microscopic spores that float through the air. Once a spore has found a dark spot, it can fester into a whole colony, which in turn produces spores that find other areas in the house to hide. As the name suggests, toxic black mold is dangerous and can cause symptoms from sinus congestion to memory impairment and body fatigue. Solve this problem by keeping plants well lit and areas around plants well maintained.
One of the most common disadvantages to indoor plants is the high possibility of insect infestation. While many infestations arrive on green plants, flowering plants and orchids are also common breeding grounds for insects and grubs. A University of Colorado study found "Infestations of scale insects are almost always established from infested plants recently purchased or received as gifts." Control the spread of infections from new plants to existing houseplants by quarantining new plants for a few weeks and checking occasionally for fungus or insects.