by Adam Downing
Virginia Cooperative Extension Agent, Forestry & Natural Resources
April 2009
The approach of Arbor Day marks the time and season for tree planting. Arbor Day founder, J. Sterling Morton, put it well, “Other holidays repose upon the past; Arbor Day proposes for the future.”
"There is a time for everything, and a season for every activity under heaven."
-- Ecclesiastes 3:1
Morton was the editor of Nebraska’s first newspaper and a big fan of trees. Unlike Virginia and other eastern states whose dominant vegetation was trees, Nebraska was, and still is, a classic Great Plains “grassland” state.. Early settlers though, still needed trees for everything from fuel to food and lumber to shade.
In 1872, at Morton’s initiative, the nation’s first “Arbor Day” was held. Settlers planting over 1 million trees created Nebraska’s “first forest” that day. Since 1894, Arbor Day is celebrated in every state of this great nation and is now spreading around the world.
Perhaps you are asking, “Why the big fuss over trees?” Good question.
Benefits of Trees
Why trees? For starters, trees take unusable (to mammals) gasses from the air and replenish the atmosphere with life giving oxygen, a fact most of us take for granted. Trees also reduce noise pollution, an audible issue depending on how close you live to a highway, factory, or other noise-generating infrastructure. Twigs, branches, and leaves accomplish this by absorbing sound wave vibrations.
Strategically placed trees around the home can increase property value and save heating and cooling costs.
Did you know that trees increase property value? Real estate with trees can command up to 20% higher values than property without trees. Couple this with the fact that trees increase energy-conservation and you’ve got a doubly attractive piece of. Well placed trees around buildings can not only reduce summer cooling costs but winter heating costs, as well, by up to 20 percent!
Trees also play an important role in maintaining and improving water quality. Impervious surfaces such as parking lots and roads are notorious for degrading water quality. As water runs off these areas, grease, oil, anti-freeze, brake fluid, de-icing salt and whatever else accumulated since the last rain, also runs off. While this may clean paved surfaces, it can severely impact streams and other bodies of fresh water. Trees help this problem by reducing and slowing runoff, acting as a filter for pollutants and increasing the portion of water that becomes ground water rather than run-off.
Improving water quality, increasing property value and cleaning the air of noise and greenhouse gases are but a “single twig of the tree,” if you will. Trees also increase economic development in shopping areas and around office buildings, provide habitat (food and cover) for wildlife, increase beauty, aid in traffic control and serve as buffers between different land-uses. And, like the early settlers, we too depend on trees for many of our everyday needs, such as housing, food (fruits & nuts), paper, cardboard, fragrances and cleaning solutions.
Trees, whether in the forest, yard, park, or street side, provide numerous benefits. Many benefits we take for granted. We may also take for granted how certain trees got to where they are. In the forest, many trees regenerate naturally from root or stump sprouts or seed germination. We may also plant trees, usually pine, to regenerate a certain type of forest. Trees in more urban or residential settings are often planted. This provides more control over the kind of tree we want and where we want it to grow.
Preparing to Plant
Tree and site selection is the first step toward planting a tree. Before you buy a tree or pickup your shovel, examine the site for your new tree. How much overhead space (height and width) is available? How much “dirt space” is available? Trees that grow tall and/or wide need more space beneath the soil surface too. Tree roots can grow outward up to 3 times the height of the tree. So, if you plant a tree that grows to an average height of 50 feet, the roots may go a distance of 150 feet away from the trunk in search of nutrients and water to support the mature specimen.
Simple tools are all one needs to plant a tree,
Another component of match making trees with planting sites is soil drainage and compaction. Certain trees prefer well-drained soils. Others are more tolerant of wet soils such as red maple, sycamore, bald cypress, willow oak, or river birch. Dogwood, Boxwood, and Japanese holly are examples of trees that do not tolerate “wet feet,” that is roots in poorly drained soil.
After selecting the right tree for the right place, preparing the site is next. Now is the time to take shovel in hand. The hole adresses the “root of the matter.”
Since the majority of a tree’s roots are in the top 8 inches, and few trees really have taproots, dig wide, not deep. The planting hole should be 2 to 3 times the width of the root ball or container and no deeper than is needed to bring the top of the root ball (or soil level if in a container) level with the ground.
Deeply dug holes often result in trees being planted too deep. When this happens, extra soil is added to make the planting site level with the ground. This results in less air and water being able to get to the roots. While planting deep is not recommened, if your soils are poorly drained, digging a hole 1 to 2 inches shallower is recommended.
Hole should be just deep enough to make the top of the rootball even with ground level.
Next we prepare the tree for planting. Balled and burlapped root balls need to have the wrapping removed as much as possible, especially the top 8 to 12 inches. Burlap wrapping material, pinning nails, rope lacing, wire baskets, etc., should all be removed to avoid damage to the growing trunk and roots.
Container grown trees, weather in pots of fiber or plastic, should be removed from the pot entirely. At a minimum for fiber pots, break away as much of the pot top as possible.
One step remains before placing the tree in the hole. Examine the root ball exterior for “circling” roots. These “dizzy” roots are headed in the wrong direction and will eventually girdle (choke) the trunk if left alone. If circling roots are visible, cut through them with a sharp knife in a few places.
Planting
The next step is what we’ve been waiting for! It’s time to place the tree in the hole. Backfill with the same soil you dug out. Do not incorporate organic matter in the backfill, this can lead to problems with getting the tree established in it’s new home. Backfill half the soil, then firmly press the soil down, and water thoroughly to settle out air pockets. Finish backfilling with the same procedure in 1 or 2 more stages till the hole is filled to a level even with the surrounding ground.
After Planting
Last but not least, is providing proper care of your new tree. Planting a tree may be stressful to you but it is certainly a stressful experience for the tree. There are a few things you can do to make its transition easier. First of all, remove all tags and labels to prevent girdling of branches and trunks as it grows. Newly planted trees often need watered, especially during dry periods. Drip irrigation and slow release water reservoirs are best at getting water beneath the soil surface to thirsty roots.
Mulching is one of the best measures to help your new tree along. Organic mulch, such as wood chips, pine bark and compost are best since they also add nutrients as they decompose. Proper mulch conserves soil moisture, making the job of watering easier.
Don’t over mulch, or allow mulch to touch the trunk. Too much mulch suffocates roots. Mulch piled up against the trunk is a volcanoe waiting to explode. It is an invitation for rodent and disease problems. A layer 2 to 3 inches deep is best – less if the mulch is “fine”, more if it’s “course.” For added weed control, permeable landscape fabrics, that allow air and water to pass through, can be placed under the mulch.
Only stake trees with large crown or those on windy or vandalism prone sites. Most trees, if properly planted, do not need staked. If needed, take care not to damage the bark and allow a slight amount of flex to encourage natural strengthening. After a year, staking should be removed.
Another overused protection measure is trunk wrapping. Most trees should not have their trunk wrapped. It often increases disease and insect damage by providing ideal habitat for those organisms. If protection from rodents is needed, or desired, install loose fitting guards around the base.
A properly planted tree often outlives the one who planted it, benefitting generations to come..
Most trees are pretty tough. Scores survive for many years despite sorry sites, poor planting practices and after-planting apathy. Perhaps this is one of the reasons why many people admire trees.
They do, after all, include a representative that is the longest living organism known on earth, in one of the most inhospitable places on earth. Just north of Death Valley in California lives “Methuselah,” a 4,767 year old ancient Bristlecone Pine.
While trees we plant will not live that long, their benefits may very well outlive us. The simple act of planting a tree leaves a legacy for future generations.
So, get out those shovels -- Arbor Day is a good time to plant!
