A few years ago, I mentioned to a friend that it was Arbor Month, what I consider the most important month of the year.

My friend replied, “I’ve heard of Arbor Day, but is there an Arbor Month?”

My immediate reaction was, “Yeah, it’s April! Everyone knows that, right? Why would we restrict honoring something as important as trees to a single day of the year?”

At that point, I knew I was fooling myself. I honestly had no idea when Arbor Day was or if there was a full month devoted to trees. Yet, as a tree aficionado, my friend’s question had me curious.

With a bit of research, I learned that Arbor Day is the last Friday of April, and technically there is no such thing as Arbor Month.

Although disappointing to discover, at that moment I decided the trees in Missoula should not only be celebrated one day in April, they should also be honored the entire month, and I’d be their ambassador. Here’s why.

Take a look at this Missoula shaded sidewalk and this tree-lined street.


First, notice their beauty. Not only is each tree beautiful in its own right, but the aesthetic quality of many trees grouped together in an urban environment has a positive effect on the entire area’s character.

They soften the hard edges and surfaces of our built environment and create a sense of place. If you don’t know what I mean by that, just walk down a street void of trees. Where would you rather live?

Because of this “sense of place,” trees help improve relationships and communication among neighbors and friends. They draw people outside and provide a place to gather, fostering a stronger sense of unity and belonging. We want to walk, play, and rest under and around trees.

Additionally, trees improve our quality of place by providing important habitat for wildlife. How much richer are our worlds with the sights and sounds of songbirds, chipmunks, bees and other pollinators?

And while we’re admiring trees for their inherent beauty and enjoying their shade, these organisms are hard at work mitigating the damaging effects we have on the environment. They have their work cut out for them.

When cities grow, trees and green space are replaced with buildings, concrete and asphalt, leaving storm water and snowmelt nowhere to go.

If we don’t carefully plan our cities and towns, man-made infrastructure creates “urban heat islands.”

Additionally, we live in the comfort of heated and, increasingly, air-conditioned homes which add greenhouse gases to our atmosphere, driving climate change and further warming our already hot summers.

We drive cars and trucks that release fumes and congest our air. Trees can help mitigate these problems.

So we need to take care not to develop and expand our cities at the expense of our valuable trees and green space, the very things that have the power to counteract our impact on the environment and make our cities healthier, more livable and resilient.

How do trees take care of our mess?

Every part of a tree intercepts storm water and snowmelt, slowing it down and keeping it on site, allowing the groundwater to recharge. Trees also help capture storm water and divert it to the soil where it is filtered, thereby reducing the amount of pollutants reaching our waterways via runoff.

As our city grows and more people rely on clean water for drinking and recreation, trees and green space are an even more valuable community asset. We can honor trees by prioritizing them during planning and development.

Trees lower surface and air temperatures by providing shade and through evapotranspiration, the release of water into the air. The overall cooling effect of trees lessens the urban heat island effect; shaded surfaces can be 20 to 45 degrees cooler and ambient air temperatures 2 to 9 degrees cooler.

If we plant trees strategically, we can reduce energy use by shading buildings in the summer and blocking cold winter winds, cutting back on the need for both air-conditioning and heating.

Trees intercept and store gaseous pollutants and sequester CO2. They also shade cars and parking lots, reducing ozone emissions. Our increasing population will bring more vehicles and pollutants, which means more trees need to be planted along our streets and in and around parking lots.

I could keep going. In addition to the environmental benefits of managing and filtering water, cooling temperatures and cleaning the air, trees provide enumerable social, economic and health benefits.

There’s so much benefit to trees and our urban forest, I can talk about them year-round, so shouldn’t there be more than one month of tree celebration?

During my search for Arbor Month, I learned that October (a great time of year to plant trees) has been dubbed NeighborWoods Month by the Arbor Day Foundation, so we have two months to celebrate and honor trees. Now, that feels right.

We all need to support our trees, and Missoula’s Parks and Recreation Department, and the myriad local groups working to green our town. What can you do today to support Missoula’s urban forest?

  • Plant trees: Spring and fall are the best times. Do be mindful to choose the right tree for the right place. Learn more at treesformissoula.org.
  • Care for trees: Keep them watered and protected. Mature trees provide maximum benefits and need deep watering in late summer and early fall.
  • Become a Trees for Missoula volunteer. Activities include summer tree inventories, fall plantings, and winter pruning. Contact Karen.Sippy@treesformissoula.org
  • Join in Run for the Trees April 14 or any of the April events listed below.

I hope you celebrate and honor trees in your own way each day of April and throughout the year.

Karen Sippy is executive director of Tress for Missoula. She partners with Missoula’s Parks and Recreation Department. and Climate Smart Missoula to grow our urban forest.

Upcoming Arbor Month, Earth Month and Sustainable Missoula events:

April 5. Climate Smart’s Monthly Meetup – Urban and Wildland Forests and Open Lands. 5-7 p.m. Imagine Nation Brewery. Details here.

April 14. Run for the Trees – Supporting Missoula’s Urban Forest. Learn more and register at www.runwildmissoula.org.

April 14 – 22. International Wildlife Film Festival. Wildwalk parade, celebration, and films galore.

April 21. Clark Fork Coalition River Cleanup

April 22. MUD’s Annual Earth Day Celebration

April 27. Arbor Day Celebration at the State of Montana Arboretum at UM

All 2018 Earth Month (and Arbor Month) events are here.