“I think that I shall never see a poem lovely as a tree” Trees by Joyce Kilmer
“Under the spreading chestnut tree the village smithy stands” The Village Blacksmith by Henry Wadsworth Longfellow
A Tree Grows in Brooklyn by Betty Smith
The Giving Tree by Shel Silverstein
Don’t forget Johnny Appleseed!
Trees have long held a prominent place in American literature and folklore, just as they hold a prominent place in our landscape. Trees are long lived, have great ornamental value, provide shade, fruits and nuts, and are used for screening, as sound barriers and windbreaks. Through the process of photosynthesis, trees use carbon dioxide and produce oxygen, earning them the designation “Nature’s Air Conditioners.” With all they have to offer it’s no wonder that they have such an important place in our landscapes, environment and our literature.
We are fortunate to live in a well-forested urban environment. Minneapolis was at one time one of the ‘leafiest’ cities in the United States and so we tend to take our trees for granted until something happens to devastate large numbers of them — like the tornado which took down nearly 3,000 trees in North Minneapolis in 2011. The tornado was a harrowing event, but there are many reasons why trees die in a less dramatic fashion, some of which we have no control over but some which are the result of human behavior.
Most trees die for a number of environmental reasons. Diseases such as Dutch Elm Disease, Oak Wilt or Verticillium can spread to epidemic proportions and kill many trees before we know it and can do anything to control them. Pests such as rabbits or deer can attack individual trees; chewing the bark, girdling the base and killing the plant. Insect pests kill many trees each year; the most notable recently is the Emerald Ash Borer which is attacking our ash trees. Gypsy Moths can completely defoliate a tree, which if it is unhealthy or unduly stressed can kill the tree. Japanese Beetles can feed on linden, apple, birch, maple and walnut trees. Once again healthy trees can survive the defoliation but unhealthy ones may die. One thing all these insect pests have in common is that they are non-native insects which have no natural predators here. They were transported here unintentionally, very often in shipping crates, and so to a certain extent the damage they cause is a result of human activities.
Some trees die because they are non-native trees that cannot adapt to either the soil or the climate. Our climate can be very hard on trees; the winters can cause root injury. The majority of a tree’s roots are in the top 12” of soil and extend beyond the drip line. Temperatures of 0º-10º can kill tree roots. Fortunately the soil cools down slower than the air and snow is a natural insulator which protects most trees in Minnesota. Also moist soil cools slower than dry soil which is why we need to keep watering our trees throughout the fall. This brings us to another environmental factor which can cause trees to die, drought.
Our efforts to slow down climate change encourages us to soften our carbon imprint by using compact fluorescent/LED bulbs, reusable drinking bottles, cloth napkins, reusable shopping bags, natural cleaners, no-VOC paint, shopping for locally produced goods/services, recycling and composting. These are all simple and good things that we can do to help reduce the impact of climate change. But another very green thing we can do is – plant a tree.
I have been thinking a lot about trees lately. We lost our 85 year-old elm tree to Dutch Elm disease last summer and we now have the opportunity to plant a new one! But it does take a lot of consideration to choose the right tree for the right spot. Not all trees have the same needs and not all sites have the same characteristics. We should assess the site as to whether it has wet or dry soil, whether it is sunny or shady, and the amount of wind exposure, and then choose a tree that can thrive in those conditions. We must consider the mature height of the tree and we want to avoid trees that are susceptible to disease or pests, such as Dutch Elm or Emerald Ash Borer. There are several other characteristics we want to consider, such as shape and fall color and so next month I will share with you the types of trees we are considering and maybe even what we may have decided to plant.
Advice from a tree: Stand tall and proud·Sink your roots into the earth·Be content with your natural beauty·Go out on a limb·Drink plenty of water·Remember your roots·Enjoy the view!