A woman stands with her eyes closed and arms outstretched in a forest of trees with yellow leaves
(Image credit: Jiyi)

During photosynthesis, plants take in carbon dioxide and release fresh, clean oxygen. This process is responsible for much of the quality of the air we breathe.

As the globe tackles things like climate change, pollution, and other environmental issues, more and more people are becoming aware of AQI (Air Quality Index). In the effort to keep AQI numbers low, fortifying and protecting outdoor plants that reduce air pollution has become a priority. Learn about plants that lower AQI by absorbing pollutants.

Keeping it Green in Cities

Plants are amazing forms of life. Not only do they provide us with food, building materials, clothing, and sheer beauty, but they also clean the air. Whether there are toxins in the air from industrial manufacturing, or a thick haze from wildfires, air quality is crucial to human health. Studies have shown that using wild plants as detoxifiers is often cheaper and more efficient than traditional mechanical cleaners.

Large urban landscapes often arise at the price of green spaces. As more and more building takes place, less and less forest, field, and riparian life is left behind. But things are changing, and modern approaches to city planning are now incorporating green spaces. These locations are filled with trees and other plants, to not only create outdoor play and exercise sites, but to help clean the smoggy, urban air.

In urban areas where such green spaces were not included in planning, campaigns to install trees are taking place. Such is the case in places like London and Paris. Urban forests have the capacity to scrub air, making the environment healthier for all citizens, especially those with respiratory delicacy. Adding trees in cities helps clean air in several other ways. They shade buildings, reducing the need for air conditioning and thereby reducing greenhouse gasses. Lower temperatures also minimize the production of harmful low level ozone pollutants.

Types of Air Purifying Outdoor Plants

While all flora scour the air of carbon dioxide, they also filter other toxins. However, some plants are better at cleaning the air than others. Trees are very effective at removing tiny particulate matter that can be irritating to lungs. These particulates can be microscopic and come in the form of dust, chemicals, acid, and other toxic particles from factories, construction sites, and other pollution emitting areas.

What plants remove pollutants best?

  • Conifers, such as pine and cypress, seem to be most effective in removing particulate matter. This is most likely due to their evergreen nature, which sees them active through the year.
  • Trees native to the area are ideal choices, whether they are deciduous or evergreen. Native plants are more manageable because they are well adapted to local soil, weather, and resistant to many insects and diseases.
  • Plants with larger leaves trap more particulates, as do those with rough or hairy leaves.
  • Silver birch, yew, and elder trees have been found to trap up to 70 percent of particulates.

Developing an Air Quality Garden

Individual gardeners can do their part to keep the environmental air clean. Incorporating native flowers, grasses, and other plants forms an ecosystem that not only helps purify air, but encourages biodiversity, provides food and habitat for insects, birds, and mammals, and requires less management than traditional lawns.

Adding trees produces a canopy with rich benefits. Studies have shown that restoring a native tree canopy can reduce air pollution by 27 percent. Here are some excellent air scrubbing trees:

  • Norway maple
  • Turkey oak
  • Eastern red cedar
  • Silver birch

Smaller plants to include in an air quality garden are:

  • Boston fern
  • Peace lily
  • Lady palm

Reducing the size of lawns also helps keep air clean. The mechanical maintenance of lawns adds emissions and particulates to the air. Replacing lawns with a low maintenance plant such as moss keeps such pollutants to a minimum.

Pollen Pollution

One particle of particular concern is pollen. Planting trees and plants with large blooms that are pollinated through insects helps minimize pollen fall out. Some idea trees are:

  • female ash
  • female maple
  • magnolia
  • dogwood
  • cherry
  • fir
  • spruce
  • flowering plum
  • yellow poplar

These trees all produce less pollen pollution, making them more desirable in an air quality garden.

Bonnie L. Grant

Bonnie Grant is a professional landscaper with a Certification in Urban Gardening. She has been gardening and writing for 15 years. A former professional chef, she has a passion for edible landscaping.