Trees, part one
Making a good investment
If you own an old home like mine, you're living with someone else's decisions, such as where trees are planted in your yard. I'm fortunate to have three 40-year-old trees that provide shade in the summer and great fall color. But they also have provide headaches.
A sweetgum tree fills my front yard. While its leaves turn wonderful shades of yellow and orange in the autumn, this tree also drops bushels of sweetgum balls. A white birch shades the west side of my house, decreasing my summer utility bills, but it's also prone to bronze birch borer. A stately bur oak covers most of the backyard, but it's now just 10 feet from a power line.
Selecting a tree is one of the most important decisions a homeowner will make. They're an investment for future generations, since most people move before their trees reach mature height. That's the way it should be: a properly placed and cared for tree will most likely outlive the person who planted it.
Consider these factors first:
Why are you planting a tree? Do you want shade, fruit, flowers, or fall color. Do you want a privacy screen or a windbreak?
Where do you want to plant it? How close are sidewalks, patios, driveways, and buildings? Trees need space both above and below the ground. The area must be large enough to accommodate the roots and the mature trunk's diameter. Tree roots generally remain in the top 12 inches of soil and spread 1.5 to 2 times the width of the crown, or branches, of the tree.
What about the tree's mature height and width? Will it interfere with any utility lines?Avoid planting beneath power lines whenever possible. If you do plant trees under power lines, it's recommended that you select a tree with a mature height of less than 20 feet. Tall growing trees will require pruning, which results in a lopsided, stressed tree.
What are the site's conditions? Select a tree that will thrive in the given set of conditions--sun, wind, soil, and drainage. The number-one cause of tree death is its location. Few trees do well in light shade--most prefer full sun. Newly planted trees in windy areas will require more frequent watering, and they may need staking. In central Illinois, select a tree that is hardy for zone 5B. Most trees prefer fertile, well-drained soil. At new home sites, the topsoil has often been disturbed. Sometimes it's gone, or it's shallow and compacted. This will put trees under stress. Have your soil tested to determine fertility needs and the pH level. You can then improve the soil with fertilizer or soil amendments--such as sand, peat moss, or manure--before planting.
Poor soil drainage can remove oxygen that is needed for tree roots to thrive. Test soil drainage by digging a hole one-foot wide and one-foot deep; then fill the hole with water and see how long it takes for the water to drain. If it takes more than 6 hours, you probably have a drainage problem.
Every plant can have disease and insect problems. Select tree cultivars that are resistant to life-threatening pests.
The information you have gathered about your site conditions and your aesthetic preferences will guide you in your search for the perfect tree. Remember, a vigorously growing tree planted in the right place will result in years of happiness. A tree that's not matched to the site will result in years of frustration. Next week's column will highlight trees that will thrive in our area while adding beauty to your landscape.
For more information on tree selection and care, visit the International Society of Arboriculture's Web site at www.treesaregood.com.
Checklist for Purchasing a High-Quality Tree
A high-quality tree will have the following characteristics:
An adequate-sized root ball with healthy sound roots. Roots should not be crushed or torn. And they shouldn't circle around the container or be twisted. Circling roots often girdle or kill other roots and can eventually kill the tree.
A visible trunk flare. The flare is the spreading trunk base that connects the roots.
No mechanical wounds on the trunk. If the trunk is wrapped, remove the wrap and inspect the trunk for wounds.
No wounds from incorrect pruning.
Evenly spaced branches. Branches should be firm and strongly attached to the trunk.
A strong central leader. Avoid trees with two or more stems squeezing together or several branches on the same position of the trunk. As the branches grow larger and tighter together, the chances for splitting increase.
Always purchase trees from a reputable business.