Why is Tree Diversity so Important in an Urban Canopy?

Why is Tree Diversity so Important in an Urban Canopy?


Since its discovery in Michigan in 2002, the Emerald Ash Borer (EAB) beetle has destroyed tens of millions of ash trees across the Midwest and tallied an estimated $11 billion worth of damages between 2009 and 2019. The EAB devastation also caused the loss of hundreds of millions of dollars to municipalities and tree nurseries, as the ash tree was a hearty and commonly planted parkway tree.

Flossmoor itself lost significant canopy coverage due to the EAB, which is when the Village started placing heavy importance on diversifying our urban forest.


There are three common goals in diversifying the urban canopy: improve habitats of local wildlife, improve the resilience to disease and age, and support the local ecosystems.


With more than 300 trees soon to be planted for Plant the Gem, the Village of Flossmoor made it a priority to identify a wide range of tree species to be distributed across the community, landing on a total of 10 different species.


The highest number of trees to be planted for Plant the Gem will be the Northern Catalpa. Catalpa currently makes up a very low percentage of Flossmoor’s tree canopy and with an average growth of 12 to 24 inches a year, the northern catalpa can grow to its full size in as little as five years, making it a perfect candidate for parkway planting.  

The majority of the remaining trees for Plant the Gem will come from the oak species, an important environmental species that serves a number of area wildlife. In addition to the expected squirrels and other critters interested in the oak’s acorns, trees of the oak species are also host to over 500 moths and butterfly species, especially during the caterpillar state, which are an important food source for many birds.


All of the trees selected for Plant the Gem are native Midwestern species that thrive well in parkways. The selected trees also have various growth rates, soil and sun preferences, and other environmental preferences, which will serve well in adding to the healthy and robust urban canopy of Flossmoor. Learn more about all of the selected trees below!



Northern Catalpa – Catalpa is a Midwest native tree that grows 40 to 60 feet tall, with a narrow, open, irregularly rounded crown and spreading branches. 


Chinkapin Oak – Chinkapinn oak is a Midwest native tree that grows 50 to 80 feet tall, with a pyramidal, round shape and a slow to moderate growth rate.


Swamp White Oak – Swamp white oak is a striking tree with attractive peeling bark that grows 50 to 60 feet tall, with a broad and round shape with messy fruit and plant parts.


Northern Red Oak – Northern red oak is a Midwest native and is one of the faster growing oaks for the home landscape reaching heights from 60 to 75 feet tall. 


Bur Oak – The stately bur oak, native to the Midwest, is a great choice as a shade tree and for specimen plantings in parks, spacious yards, and other large areas, and grows 70 to 80 feet tall.


Tuliptree – The tuliptree is one of the largest native trees in North America growing to as tall as 70 to 90 feet. It is a member of the magnolia family and has distinct tulip shaped flowers.


Hackberry – Hackberry is a Chicago-area native and a sturdy, tolerant shade tree for parkways, parks, and other large areas and it grows between 40 and 60 feet tall.


American Hornbeam – The American hornbeam is a small, native forest understory tree that grows 20 to 25 feet tall, making it useful for shady landscapes and naturalized or woodland gardens.


River Birch – River birch is a popular, fast-growing native tree that thrives well in high moisture areas and grows to between 30 and 40 feet tall.