The Bald Cypress Is a Mean Green Urban Filth-Cleaning Machine

A Robust Contribution to the Canopy

While all trees absorb pollution, big, mature trees tend to be the best performers. The Bald cypress is a frontrunner in this group, and it has certain characteristics that not only make it an excellent tree for filtering urban pollution but also a beautiful choice to incorporate into Nashville neighborhood landscapes. 

Bald cypress is a conifer with an attractive canopy that offers shade as it matures.

Characteristics of the Bald Cypress

Bald cypress trees are known for their presence in swamps of the South – in fact, it’s the state tree of Louisiana. But these trees have a wider range, stretching northwards to Maryland and westwards to Missouri. The tree’s particular characteristics have allowed it to adapt to various soil conditions and climates. 

The Bald cypress is a conifer, which does well in slightly acidic soils (like those usually found in urban areas), but it is one of the rare types of conifer that loses its needles  in winter.

A young bald cypress tree in Belle Meade's Parmer Park.

The tree’s height is part of its appeal. A mature specimen can reach 50 to 70 feet in a neighborhood setting, while they often tower over a hundred feet tall in the wild. In a backyard or park, the foliage provides ample shade in the summer, and since it seasonally loses all of its needles, the trees don’t block sunlight on cold winter days. 

The Bald cypress is a tough tree that is extremely well-adapted to flooding and standing water, and it has an extensive root system that anchors itself in the ground. This also makes it tolerant of high winds: the trees may lose branches or tops, but their trunks and roots will remain in place. These strong, water-tolerant roots also make them great at contributing to water management in urban areas. 

Pollution Filtration

Trees naturally absorb carbon, sulfur, nitrogen, and other nutrients from the air, soil, and water to grow and survive. When pollution from human activity, like driving cars, powering energy systems, and the various ways water gets polluted from runoff raises the concentrations of carbon, sulfur, nitrogen, and other compounds in the air, soil, and water, trees will absorb a portion of this pollution to contribute to their own growth. 

The large size and dense wood of a mature Bald cypress result in these trees absorbing more particles from the air than a smaller tree. Their high-reaching foliage helps create a physical barrier from pollutant dispersal, blocking horizontal spread and collecting particles that fall from above on their leaves before they can reach the ground below. The shade they cast in the summer not only cools the area immediately around the tree, but these lower temperatures help prevent ozone from developing at ground level (ozone is a gaseous mix of toxic chemicals that forms in polluted air on very hot days).

The Bald cypress is perhaps best known for its ability to grow in swampy areas, but it is also becoming a popular choice in urban areas.

Bald cypresses can similarly take up pollutants from water and block the spread of them in groundwater and surface waterways. Their dense root systems absorb and store a fair amount of water, and they contribute to sturdy soil that can hold water in storm or flood conditions. These trees are frequently planted along rivers and lakes to support and protect them, and they can also be planted in parks and yards to help manage water runoff. 

A Native Solution to Reducing Pollution

Bald cypress trees are among the best choices of big, pollution-absorbing trees to plant in your neighborhood. While you have to be sure to plant them far enough from your home that their wide roots don’t reach into your home’s foundation or other in-ground installations, these attractive trees can be planted for their functional ecological purposes and also be appreciated for their appearance. The Bald cypress’s flared base, soft green foliage and rusty autumnal coloration make it a wonderful addition to a yard or park.

Check out the Bald Cypress’ listing in our tree sale catalog to learn how you can plant one of these powerhouses. Sign up for our newsletter to stay updated on how we can work together to support Nashville’s canopy!