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An Oregon Homeowner’s Guide to Tree Care Additional tree care information Hiring an arborist When the job is too big for you to handle safely, it’s time to call in a professional. Hire someone who is bonded, licensed, and insured in Oregon. Take your time and select a company you know is reputable. Look for a certified arborist, someone who has passed the International Society of Arboriculture (ISA) certification exam. You can find a local certified arborist by visiting: www.treesaregood.com or www.pnwisa.org. When choosing an arborist, be aware a good one rarely recommends topping and will be able to explain why it is no longer an accepted method of proper pruning. In addition, a good arborist will not climb your trees using spikes or spurs as these tools open wounds that provide a pathway for disease and insects to potentially weaken or kill your tree. Resources Additional tree care information is available from your local Oregon State University Extension office, professional arborists, and a variety of online resources. In addition, be sure to check with your local government for permits or requirements related to trees that may need to be followed in your community. In addition to information about hiring a certified arborist, the ISA Pacific Northwest Chapter, www.pnwisa.org, contains information on landscape tree care and hazard tree prevention. The Arbor Day Foundation, www.arborday.org, also offers tree planting and care information for homeowners. Learn more about urban and community forestry in Oregon by visiting Oregon Community Trees at: www.oregoncommunitytrees.org. Oregon Department of Forestry Urban and Community Forestry Assistance Program 2600 State Street Salem, OR 97301 Phone: [PHONE REDACTED] www.oregon.gov/ODF/urbanforests Oregon Department of Forestry Oregon Department of Forestry Promoting and Practicing Promoting and Practicing Sustainable Forestry Sustainable Forestry The right way to plant a tree A few questions to ask yourself BEFORE planting a tree. What functions will the tree serve? Do you want shade, a windbreak, a screen, or fall color? The answers to these questions will determine your species of choice. What is the soil like? Sand or clay; poorly drained or well- drained? Good quality soil that is uncompacted and well- drained, with access to an adequate water supply, will promote healthy tree growth. Does the site provide enough room for the tree’s branches and roots to grow? Make sure there are no utility wires or other obstructions underground or overhead that may interfere with the tree as it grows. Proper tree care Proper tree care can often be a mystery. Plant a tree and nature will take care of the rest, right? Not necessarily. The trees in our yards, neighborhoods, and cities are a valuable asset, and they require our help to keep healthy. Trees contribute to the quality of our lives by cleaning our air, cooling and shading our homes, and increasing property values and the attractiveness of a community. Proper tree care is important because trees are an investment in the value of your home and the livability of your neighborhood. This guide will provide you with techniques on how to properly plant, prune, and care for your trees, so that your trees are healthy and keep working for you. How to have the best looking trees in your neighborhood Practice right tree, right place. Select tree species with growth characteristics that match the planting space and site conditions. For example, because of their height, tall trees like a Douglas-fir should not be planted under powerlines. Mulch your trees. Mulching helps keep soil moist and provides a protective barrier about the base of a tree. Apply mulch several inches thick and extending out several feet from the tree, keeping it away from the trunk itself. Give your trees a drink! Newly planted trees and even established trees need water regularly during drought conditions. Keep lawn care equipment away from trees. Injury to a tree’s trunk, roots, and branches from lawn care tools can cause decay and may lead to the tree’s decline. Leave roots alone. Roots support, anchor, supply water and nutrients, and store energy for a tree. Damage to tree roots is a common cause of tree death in urban areas. Make correct pruning cuts. Prune according to national standards. This method of pruning benefits your tree’s health, thus benefiting you! Remember to never top your trees! Proper planting steps 1. Find the point where the top-most root emerges from the trunk. Remove soil from the top of the root ball so that the top-most root emerging from the trunk is at the surface. 2. Dig a shallow planting hole as wide as possible. Dig the hole shallower than the depth of the top-most root and twice the diameter of the root ball. 3. Slide the tree into the planting hole and remove material. Carefully slide the tree in the hole with the top most root 1-2 inches above the landscape soil. Materials used to transport the tree including twine, burlap, and a basket or container should be removed – unless doing so will void a warranty. 4. Backfill the hole and add mulch. Before backfilling, straighten the tree in the planting hole. Backfill the soil into the planting hole breaking up soil clumps. Apply a ring of mulch 2-4 inches deep extending 2 feet out from the base of the tree. Keep mulch away from the trunk. Water your tree once planted. 5. Stake and prune the tree, if necessary. Staking may be needed to hold roots firmly in the soil especially if you live in a windy environment. Stake the tree until the roots are established, but no longer than one growing season. Light pruning may also be needed to remove broken or dead branches from the tree. Illustration by Edward F. Gilman, Professor, Environmental Horticulture Department, IFAS, University of Florida This brochure was published with the assistance of the USDA Forest Service PNW region. The USDA is an equal opportunity provider and employer. ---PAGE BREAK--- Removal cut Prunes a branch back to the trunk or a parent branch. Reduces canopy density and allows light to penetrate the canopy and encourage growth on the interior branches. Reduction cut Shortens the length of a stem by pruning back to a smaller limb large enough to assume dominance. Reduces canopy size and improves the structure of older trees. Never remove more than 25% of the canopy. A pruning primer Making careful and correct pruning cuts and pruning at the correct time of year is one of the best things you can do for your trees. Regularly scheduled tree pruning improves tree health and form, controls growth, and increases tree strength. Pruning can also help with certain homeowner problems such as providing clearance, improving a tree’s appearance, and improving a view. These guidelines and accompanying graphics will help you make the right cuts: How to develop a dominant stem in your tree Developing a central, dominant leader starts by identifying the stem that will make the best leader. Typically, this is the largest stem. This might be easy for some trees and more difficult for others. If all stems are about the same size in diameter, pick the one that is closest to the center of the canopy to be the leader. Then determine which stems are competing with that leader and decide where to shorten or remove these competing stems. Pruning the stems represented by the dotted lines removes two of the three codominant stems. This helps establish a single dominant leader and better tree structure. Illustrations used by permission from Edward F. Gilman, Professor, Environmental Horticulture Department, IFAS, University of Florida (top and bottom right) and Space for Life, Montreal, Canada (bottom left). Removing a competing branch Removing a competing leader Limb removal There are three steps to making a proper pruning cut that will minimize damage to the tree. 1. Make a cut on the underside of the branch about 1 ft. from the branch collar. 2. Make a second cut above the first to remove the branch. 3. Remove the remaining stub making sure to keep the collar intact. * Never “flush cut” a tree by removing the branch collar. Always use sharp tools and make clean cuts. Use caution with sharp tools and power saws. Remember, safety first. When to Prune For deciduous trees, prune branches in winter or early spring before the leaves form or following growth in late spring or summer when leaves have developed. Conifers can generally be pruned any time, using caution during their flush of growth in early summer. Dead and dying branches can be pruned anytime. Tree care: do you know? Why topping hurts trees Topping, sometimes called heading or tipping, is the indiscriminate removal of a majority of a tree’s branches which violates the accepted methods of proper pruning. Although many people think that topping will help their trees, it is actually one of the worst things you can do to your tree! Not only does topping remove leaves that supply nutrients to a tree, it actually creates a more dangerous tree! Branches that “sprout” after topping are weakly attached and are more likely to break in a storm event. Topping also makes your tree prone to insect and disease damage because improper cuts invite decay. Topping is expensive because it will not keep your tree small unless repeated every year, and it will shorten the life span of your tree. By contrast, the positive effects of proper pruning will make your tree healthier and extend its life. FIRE WISE FACT: In Oregon’s wildfire-prone areas, homeowners need to take steps to minimize the fire hazard around their homes. Fire-resistant plants, carefully placed and maintained, can help protect your home and property. Newly planted trees along the coast may need extra staking due to strong winds. Remember to remove staking materials when the tree can stand on its own. In the High Desert region, newly planted trees benefit from winter watering. Water when the soil is not frozen so that water can percolate down to the tree roots. Statewide, newly planted trees need extra water to survive Oregon’s drought prone summer season. Make sure new trees get water at least once a week during these months. Debunking tree Research has dispelled some long-held tree care Here are some facts you may not know: FACT: Cutting branches flush with the trunk will rob the tree of natural chemicals used to close the wound. This will lead to decay in the tree and will shorten the life of the tree. FACT: Once mature, most trees do not have a taproot. They have anchor and feeder roots that are mostly in the top three feet of soil and often extend beyond the canopy width of the tree. FACT: Painting wound dressing on pruning cuts is unnecessary and can actually hurt the tree by causing the pruning cut to seal slower. Opens foliage Reduces limb weight Retains tree’s natural shape Preferred method of tree pruning Main Leader Main Leader Removed Reduces branch length Reduces leader height Used on large trees Replaces heading cuts Secondary (Lateral) Branch Don’t let this happen to your trees! Secondary (Lateral) Branch Removed Tree care around Oregon In Portland and the Willamette Valley, Oregon white oak trees are increasingly threatened by development, over-watering, and neglect. If you have a native oak tree, take extra care to preserve it.