Sunday, February 12, 2012

Arbor Day in Georgia

Arbor Day is celebrated on different dates throughout the U.S. due to climate differences. For Georgia it is the third Friday in February – this will be February 17th in 2012.  National Arbor Day gets a lot of attention in late April, but in Georgia it is better to plant trees much earlier when trees are dormant, temperatures are cool, and winter rains are possible.

With Arbor Day coming up this week, I’d like to talk about the following three points:

  • Why it’s important to plant trees
  • Why it’s important to plant native trees
  • Why some native trees might be a better choice than others

Importance of planting trees

When my kids were in elementary school I would organize an Arbor Day event on behalf of the PTA.  Most years we gave out seedlings that we purchased from the Georgia Forestry Commission.  The kids loved the event, and the older ones could easily answer the question about what benefits do trees provide: Oxygen, shade, food for us and wildlife, shelter for wildlife, beauty, and protection against soil erosion.  They also provide wind breaks, and they can provide privacy.

Why native trees

So you might think that it doesn’t matter what kind of tree you plant, but it does matter.  Native trees support native insects and so they also support the creatures that rely on those insects – the whole local ecosystem has grown up around native trees and it depends on them.  There are insects whose larval form feed exclusively on a plant or group of plants – insects such as the eastern tiger swallowtail butterfly (Papilio glaucus).  Eggs are laid on the leaves of wild black cherry (Prunus serotina) and tuliptree (Liriodendron tulipifera); the caterpillars that hatch will consume a small amount of the overall foliage.  Choosing to plant a non-native tree instead reduces the biomass available for specialized insects, resulting in fewer insects overall.  There are studies that show that specialized native insects (most of what we have) cannot adapt to eat non-native plants. Fewer insects equals less food available for the birds that feed these caterpillars to their chicks.  

Why some native trees are better choices

In the paragraph above I talked about why choose a native tree over a non-native one.  Now I'll like to talk about why choose particular native trees rather than just "any" native tree. Think "native" on a smaller scale - the environments in which you live need the indigenous plants that support them.  For example, growing blue spruce (Picea pungens) in north Georgia adds nothing to the local environment - it is as alien to the insects that live here as a plant from Europe because it is native to the western United States.

Consider also diversity when choosing a tree.  If your area is full of oak trees, consider planting something else instead of another oak.  Doug Tallamy, entomologist and author of Bringing Nature Home, has created a top twenty list of woody plants (and perennials) for the mid-Atlantic region.  This list is based on the number of different species of Lepidoptera they support - those caterpillars that the birds love to eat!  While oaks are first on the list, adding a hickory (Carya sp.) or birch (Betula sp.) to your yard would allow you to support much more biodiversity.  

Take a survey of not only your yard but the areas around you to see what native trees are already there.  But don't that list stop you from indulging in something you love like the iconic flowering dogwood (Cornus florida) or the early flowering redbud (Cercis canadensis).  If you want to attract more birds to your yard with fruiting trees then consider serviceberry (Amelanchier sp.) and hawthorn (Crataegus sp.).

So when Arbor Day comes this Friday, consider planting a tree for all the right reasons.  And if you have kids or grandkids, be sure to involve them and talk about the reasons that we plant trees and conserve them.

Eastern tiger swallowtail butterfly (Papilio glaucus)


  1. "Consider Diversity" -- YES! Great post, per usual!

  2. Great post, Ellen. :)

    You continue to educate and inspire here as you did when you hosted the Arbor Day events through the PTA. Keep up the good work.

  3. Happy (almost) Arbor Day! It's great to see those kids looking so happy to be planting trees.

  4. Serious question: Do you give much consideration to beauty when you plant trees, shrubs and plants? If so, how far down the list?

  5. What is the definition of beauty? Flowers, fall color, shape? I do plant things that I think are beautiful, but it is according to my definition so I'm not sure if that is meaningful to anyone but me. I do consider the "whole package" when considering any plant: how it looks in spring, summer and fall. I think it is a hard question to answer, I guess.

  6. Promise I wasn't bein' sassy. Many gardeners it seems go for beauty first only to find that they have planted something that outgrows it's space in one season or turns out to be an invasive nightmare.Planting for beauty, balance, color, bloom time, size, shape, pollination value, being a host plant etc is quite a balancing act and sometimes something's gotta give:)

  7. I didn't think you were sassy! Your points are very good and I always encourage people to research their plants so that they choose "right plant, right place" for all the reasons that are important to them.

  8. I had no idea that Arbor Day occurs at different times in different states!

    Your subject matter comes at a coincidental time for me, as I just went to a lecture which discussed the important roles that trees and birds provide for each other. The issue of providing native trees for native birds came up a few times and was very interesting to learn about. Thanks for offering more food for thought.

  9. We are very similar. I live about 1.5 hours south of Atlanta. I too began gardening in the mid 90's and didn't become crazy about native plants until the year 2000, when I took the Georgia Master Gardener course. Sharing the importance of native plants is why I write my blog. I know this post was written a couple of years ago, but of course it is still pertinent today. Thanks!