As a certified arborist, I guess you could call me a professional tree hugger. I recently attended the International Society of Arboriculture conference and I have a lot to share with you about trees. In part 1 of this 3 part series, I elaborated on the importance of trees and how they impact us and our planet. Now I want to discuss what types of trees are useful and how to choose the right one for your landscape.
Trees Effective at Carbon Capture
In my last blog, I spoke about climate resiliency and how trees act as a filtration system for the air around us. As deforestation increases and the global count of trees decreases, our air becomes more and more toxic to us. So how does this play into tree selection? I recently learned that only trees with a diameter of 12 inches or more are effective at carbon capture. This means that trees with wider trunks are far more efficient at pulling carbon out of the atmosphere, thus giving us cleaner air. Here is a link to more info on the subject.
Something else to consider when discussing the impact of certain trees on our air quality is leaf size, leaf structure, and canopy size. This article from 2020 states, “Bigger canopies can trap more particles than smaller ones, and larger leaves can trap more pollutants than small ones. When it comes to leaf type, it is those with rough, rugged and hairy surfaces that act as the “best filters” for PM.” “PM” stands for particulate matter or tiny air pollutant particles.
The finding that bigger trees are better for the environment supports the idea that we need to both protect our growing, large trees like oaks, pines, and hemlocks while also making the strategic effort to plant new trees that we know will grow wide and tall. However, I want to add that this doesn’t mean you should completely ignore all the little guys. All trees are good, big ones just have more benefits.
Look to the Future
All of this is to say that when I am considering tree selection, I look to the future. How tall will this tree grow? How wide will it get? How big are the leaves? Will it provide shade? What role will it play in this garden and how will it add value to the home? There are infinite questions to ask yourself when choosing a tree. I hope that air filtration capabilities are now an added category to your checklist!
5 Best Practices for Tree Selection
- 1. Consider your designated space when selecting a tree. It is important not to plant something too tall or too wide for the plot it needs to fill. Conversely, you don’t want anything too small that won’t complement the design you have laid out. As previously mentioned, we are aiming for tree longevity. We want trees that mature and create lots of carbon capture. For your tree to thrive and reach its full potential, it needs adequate room for growing and spreading. You also don’t want to risk damage to your house or other important possessions. I have seen too many trees fall over in a storm and damage someone’s car or prized Japanese maple. Also, don’t plant them too close to a road or power line. They might grow so big you have the HOA or city government on your tail!
- 2. Plant the right tree for the right site. Do research on trees and try not to select something just based on its aesthetic (I know you wouldn’t do that). For example, river birches look beautiful up close but they can often cause issues with a home’s foundation. Because River birches normally grow near streams and wet areas, their roots spread far and wide in search of water. We had a client who planted one too close to their home. The roots of the tree encroached on the home’s underground pipes and caused a burst. Check out this blog to see more.
- 3. Assess your garden space’s level of shade and water collection. Choose something that can flourish in those specific circumstances. This is a very important step in tree selection. For example, you don’t want to put a dogwood in full sun with no supplemental irrigation. They are susceptible to diseases and need shadier spots. According to UGA extension, “Drought-damaged dogwoods will develop leaf scorch, which starts as a brown band around the outside of the leaves. The cells on the outside of the leaves begin to die, and this turns the leaf edges brown.” This is just one illustration of an important lesson we have probably all learned the hard way.
- 4. Resist over-pruning! This is something I see a lot, especially with crape myrtles. Natchez crape myrtles can grow up to 30’ tall and make exquisite additions to a home or landscape with their shade and beauty. Proper pruning can showcase the trunks, as well as the canopies, but many crape myrtles suffer unmerciful disfigurements at the well-meaning hands of over-enthusiastic pruners. I recommend keeping them trimmed to a certain extent. Overexposure of their limbs means there is new thick growth at the cut that is more susceptible to aphids. Once again, we want our trees in tip top shape for battle against our environmental struggles. Click on this blog about crape myrtles to learn how to properly prune them.
- 5. Finally, if you are doing more than one tree, go for a variety. Choose trees that will compliment each other both aesthetically and naturally. A common mistake I see is when people plant a whole row of the same trees. When they are grouped together, they become magnets for certain pests and diseases. For example: You plant a row of Leyland Cypresses. One tree gets diseased and then they all fall like dominoes. Another scenario would be planting a bunch of crape myrtles in one yard. These trees attract Japanese beetles. Put a group of them together and you will most likely have a pest problem on your hands.
I could honestly go on about this for a while but I’ll spare you! There are so many beautiful trees with so many terrible stories in my books. The good news is, there are a lot of good ones too.
The thing I cannot stress enough is research. Whether it’s googling something, checking out the UGA extension website (which has a ton of helpful information), giving us a call, or chatting with your local tree nursery worker, it is very important to ask questions and consider every possibility. Trees are an important investment for our homes, our wallets, our health, and the health of our planet. They should not be chosen on a whim!