Urban Forestry

The purpose of Golden Valley's Urban Forestry Program is to ensure that public trees are properly managed and to provide residents with the correct information to care for their own trees. The many wooded residential areas in Golden Valley act as important visual, aesthetic, and economic resources and add significantly to the quality of life and the value of property within the City.

Golden Valley has received the nationally recognized designation of Tree City USA for the past several years. Tree City USA was developed by the National Arbor Day Foundation, in conjunction with the United States Forest Service and the National Association of State Foresters, to recognize towns and cities across America that meet four standards: a community tree ordinance, a legal tree governing body, a comprehensive urban forestry program supported by a minimum of $2 per capita, and an annual observance of Arbor Day.

Forestry Issues

The Value of Urban Trees

Many people view trees as symbolic, representing human traits we are taught to admire (such as wisdom and steadfastness, even in the face of adversity) The sheltering nature of trees suggests parental care, and many people equate their heritage with the deep roots of a tree. But urban trees also serve a number of more practical purposes.

Research shows that trees help reduce stress in the workplace and encourage recovery for hospital patients. The presence of community trees is linked to higher property values (as much as 27 percent), increased tax revenues, increased income levels, faster real estate sales (turnover rates), increased number of jobs and worker productivity, and increased numbers of customers or shoppers.

Because of many variables, determining the economic value of a community tree can be challenging. However, one study concluded that the annual ecological contribution of an average community tree was $270. While individual trees have value, the variability of species, size, condition, and function makes it even more difficult to determine their economic value. Aesthetics aside, trees provide many economic benefits, both direct and indirect.

Some Direct Benefits

Direct economic benefits are usually associated with energy costs. For example, tree shade can reduce air conditioning costs in residential and commercial buildings by 15 to 50 percent. Windbreaks can shield homes against wind and snow, reducing heating costs as much as 30 percent. In city areas without tree cover, streets and parking lots can raise air temperatures as much as 35 degrees. Such "heat islands" can cause cities to be five to nine degrees warmer than surrounding areas. Because of this, formulas are used to estimate monetary values of large trees for landscape and replacement costs. Some trees in the southeastern United States have been valued up to $100,000.

Some Indirect Benefits

The indirect economic benefits of trees are even greater. On average, an acre of trees can store 2.6 tons of carbon (pollution) annually and generate enough oxygen daily for 18 people. As more and more statistics are generated to show how community trees store carbon and clean the atmosphere, models show that in 50 years, one tree can generate $30,000 in oxygen, recycle $35,000 of water, and remove $60,000 of air pollution.

Community tree canopies also intercept, slow, evaporate, and store water through normal tree functions. Studies show that for every 5 percent of tree cover area added to a community, storm water run-off is reduced by approximately 2 percent. As tree canopy increases, so does air quality. Meanwhile, there is a decrease in energy costs and storm water runoff.

The facts and statistics are endless when it comes to the benefit of community trees. The benefits go well beyond economics to include sound or noise reduction, visual screening, wind control, water quality, glare reduction, wildlife habitats and, of course, aesthetic quality. The important thing to remember is beauty isn't everything.

Six Things Trees Do For You Every Day

Improve Air Quality

  • Tree leaves absorb carbon dioxide and poisonous atmospheric gases and replenish the air with oxygen for breathing.
  • The American Forestry Association found that in just one year, a mature tree absorbs 26 pounds of carbon dioxide and cleans up pollution created by a car driven 11,300 miles. That same tree also provides enough oxygen for a family of four to breathe during an entire year.

Improve Water Quality

  • Trees reduce the impact of rain, which results in less soil erosion and runoff into our storm sewers.
  • Golden Valley's wooded areas help prevent the transport of sediment and chemicals into creeks and wetland areas.

Save Energy and Money

  • Properly placed trees can reduce air conditioning needs by 30 to 50 percent.
  • Trees placed properly for windbreak protection can cut the energy used for heating up to 30 percent.

Increase Economic Stability

  • USDA studies indicate that healthy trees can increase property value by 10 to 20 percent.The National Arbor Day Foundation reports that people spend more time shopping along tree-lined streets.
  • Apartments and offices in wooded areas tend to rent quicker and have longer leases than treeless locations.

Reduce Noise Pollution

  • Trees help to absorb loud sounds from freeways and other roads.
  • Each 100-foot width of trees can absorb about six to eight decibels of sound intensity. This is beneficial to residents along busy highways, which can generate noise levels as high as 72 decibels

Create Wildlife Diversity

  • Trees provide a suitable habitat for animals and birds that wouldn't survive in Golden Valley without them.

Tree Management Tips for Homeowners

Planting the right tree, the right way, and then caring for it properly will help it grow twice as fast and live twice as long.

  • Tree Selection
  • Planting
  • Pruning
  • Common Tree Problems
  • Hiring a Tree Contractor

One of the top five reasons for urban tree mortality is planting the wrong tree in the wrong place. When planting a new tree in your yard, always consider the type of soil, and the amount of sunlight and moisture the tree will be getting. Planting the right tree will greatly increase its growth and survival rate as well as its ability to ward off insect and disease problems. Golden Valley has mostly clay soil. Be sure to identify what type of soil you have before you plant, and use the guidelines below when choosing your tree.

Trees for Clay Soils

Bicolor Oak
Red Maple
River Birch
Hackberry
Arborvitae
Black Hills Spruce
Tamarack
White Spruce
Basswood

Trees for Sandy Soils

Bur Oak
Honeylocust
Redmond Linden
Hackberry
Ginko
Hawthorn
Cedar
Junipers
Pines

Shade Tolerant Trees

American Linden
Maples
Japanese Tree Lilac
Arborvitae
Balsam Fir
Chokecherry
Pagoda Dogwood
Serviceberry

Tree Selection Tips

  • Select a tree with a single leader at the center. This will prevent the tree from splitting when it becomes mature.
  • Know the purpose of your new trees. Some people plant trees for shade, privacy, aesthetics, or to block wind or noise.
  • Know the limitations of the planting site. Are there any overhead wires? What type of soil do you have? Is the climate suitable for the tree (ie, will it survive in winter)? When the tree is full-grown, will is physically obstruct a roadway or sidewalk?
  • Buy only from reputable nurseries. Check to see if they are members of professional organizations, such as the Minnesota Nursery and Landscape Association or the Mail Order Association of Nurseries or the American Association of Nurserymen. If the nursery is local, check to see if it has a knowledgeable staff to answer questions and care for trees properly, as well as a replacement warranty (usually for one year).

Planting trees to create urban forests is an excellent goal, but if it's not done correctly the effort can be worthless. Planting requires adequate planning, long-term care, and knowledge of trees and their needs.

The American Forestry Association estimates that young trees will grow twice as fast when planted correctly and will live twice as long as trees planted improperly.

Call Before You Dig!

Before digging, contact Gopher One Call at 651-454-0002 to identify any utility lines that might be underground.

How Deep Should You Plant Burlapped or Potted Trees?

Planting too deep is one of the top five causes of urban tree mortality. Under normal conditions, root growth is best encouraged by planting the root ball even with the surrounding terrain. When wet conditions or heavy soil are problems, raising about 1/3 of the root ball above the ground will aid the spread of lateral roots. In arid climates, a basin can be used to collect precious water.

Mulch

Mulching, which involves placing shredded hardwood, bark, wood chips, decorative gravel, or other materials on the soil around the tree, can greatly enhance the tree's health. Mulch is a young tree's best friend because it:

  • increases growth rate of trees
  • eliminates competing weeds or grass
  • retains soil moisture
  • keeps soil cool in summer
  • protects the trunk from lawn mower damage and simplifies maintenance
  • increases the soil's fertility as it decomposes
  • reduces erosion
  • improves landscape appearance
  • prevents soil cracking that can damage new roots
  • helps prevent soil compaction

Mulching Mistakes

  • do not allow mulch to touch the tree's trunk
  • do not pile mulch higher than four or five inches

Proper Pruning Techniques

  • Prune when trees are young so wounds are small and growth goes where you want it.
  • Identify the best central leader and lateral branches before pruning.
  • Never use wound dressing unless you accidentally wound your oaks in April, May, or June.
  • Always remove 100 percent of the deadwood but never more than 3 percent of the live wood.
  • Keep tools sharp. Scissors-type pruning sheers with curved blades are best for young trees. Never use anvil pruners on trees.
  • When pruning large limbs, cut just outside the branch ridge and collar with a slight down-and-outward angle. Don't leave a protruding stub.
  • Never top your tree.

When To Prune

Light pruning and the removal of dead wood can be done anytime, but keep the following in mind:

Spring & Fall

Pruning deciduous trees should not be done during the fall and spring months, because decay fungi spread their spores profusely during this time and wounds tend to heal slower on fall cuts. Wait for the tree to be dormant.

However, spring is a great time to trim evergreens. The new growth can be pruned back as it is growing, which will promote an abundance of denser new growth. It is best to start when the tree or shrub is young if you're looking to control its size.

Summer

Pruning should be done soon after seasonal growth is complete, or after September 30. This enables you to direct the growth of the tree toward the crown during the next growing season Once pruned, branch growth slows. This occurs because pruning decreases the total leaf surface, thereby reducing the amount of food manufactured that is needed for root development and next year's crown growth.

Winter

Late winter is one of the best times to prune your deciduous shade trees. Many decay pathogens and diseases that thrive in trees cannot enter a tree's vascular system during the dormant season. Also, the beetles that carry the Dutch elm and oak wilt fungi are not active during this time of year and therefore won't be attracted to your tree's freshly cut branches.

It is usually best to wait until the coldest part of winter has passed before you begin pruning. This is when the City of Golden Valley prunes many of its public boulevard and park trees. Winter pruning can result in a vigorous burst of new growth in the spring. However, some species, such as maples, walnuts, and birches, may "bleed" when the sap begins to flow. This is not harmful and will stop when the tree leafs out.

Remember: Never trim oaks in April, May, or June.

Girdling is a result of roots growing in a circular direction. Root girdling can result in a weak support system for the tree. The lack of trunk flare at the base of the tree where it enters the ground is an indication of girdling.

Improper Pruning can cause problems in urban landscapes. Leaving stubs, or flush cutting branches, can lead to cankers and frost cracks that greatly reduce the health and longevity of your tree.

Lawn Mower Blight is a term City foresters use to describe tree damage caused by lawn mowers bouncing off the base of young, smooth-barked trees. This injury can cause a canker that can slowly move throughout the trunk and eventually kill the tree. You can prevent this problem by placing shredded hardwood mulch in an area with about a five-foot or greater diameter around the base of the tree.

Planting Trees Too Deep inhibits them from getting fully established. They tend to grow slowly, become less resistant to insects and disease, and eventually die.

Use of Plastic Weed Barrier: Coarsely-woven landscape fabric keeps weeds down and, unlike plastic, still lets moisture penetrate evenly throughout the root system. Organic mulch without a weed barrier is best for plant health, but if rock is used for a mulch, landscape fabric is best for letting moisture through.

Use of Wound Dressing: Many people still use wound dressing (pruning paint) on their trees, but research shows that tree wound dressing actually inhibits wound wood (callus) from forming correctly. However, if oaks are wounded in April, May, or June, wound dressing may help prevent the insect that can carry the oak wilt fungus from transferring the disease to your oak tree.

Hiring a tree removal or trimming contractor deserves the same consideration and caution that goes into selecting a doctor or homebuilder. A mistake can be expensive and long lasting, but the right choice can assure health, beauty, and a longer life for your trees.

Tips

  • Start by checking the phone directory under Trees or Tree Service. Ask friends and neighbors for recommendations.
  • Beware of door-knockers. Most reputable companies have all the work they can handle without going door-to-door.
  • Ask for certificates of insurance, including proof of liability for personal and property damage and worker's compensation. Call the insurance company to make certain the policy is current. Under some circumstances, you can be held financially responsible if an uninsured worker is hurt on your property.
  • Ask for references and talk with former clients. Experience, education, and a good reputation are signs of a good arborist.
  • Have more than one arborist look at your job and give you estimates. Don't expect one contractor to lower a bid to match another's, and be willing to pay for the estimate if necessary. Three or more cost estimates are worth the effort.
  • Ask if the arborist will use climbing spikes. A good arborist will not use climbing spikes if the tree is to remain in the landscape.

Condemned Tree Removal Q & A

Q. Who is responsible for removing condemned diseased trees?

A. The City is responsible for removing trees from public property within 20 days of disease confirmation. Property owners are responsible for removing condemned trees from private property.

Q. What are the regulations regarding tree removal from private property?

A. State and City regulations require you to cut down marked trees and properly dispose of all portions. Removal must be completed 20 days after disease confirmation.

Q. How do I get my tree removed?

A. The City of Golden Valley does not contract for tree removal from private property. Consequently, you have the option of removing the tree yourself or hiring a qualified tree removal service. When hiring a tree service:

  • Acquire several bids to assure yourself a fair price. Make sure the quoted price includes taking the tree down, removing it from your property, and disposing of it properly. Stump removal is not required if it is debarked. Request proof of insurance (both liability and worker's compensation) from the contractor.
  • Ask for recent references and check them to determine contractor ability and quality of work. Check with the Better Business Bureau as well.

Q. What happens if I do nothing about removing my condemned tree(s)?

A. If no action is taken by the property owner 20 days after notice of removal, the City will issue a "Forced Removal Notice" and have the tree(s) removed. The cost of removal, plus an administrative surcharge, will be assessed against the property owner's tax liability.

Q. Can I store elm wood on my property?

A. A property owner may NOT store elm wood unless all of the bark has been removed. If the stump is not removed, all above-ground portions must be debarked. These restrictions apply to all elm species.

Tree Diseases & Pests

Several tree diseases and pests pose a threat to the urban forest.

  • Emerald Ash Borer
  • Gypsy Moth
  • Dutch Elm & Oak Wilt Diseases

The Emerald Ash Borer (EAB) is an invasive beetle that attacks and kills ash trees. Its larvae kill ash trees by tunneling into the wood and feeding on the tree’s nutrients. Since its accidental introduction into North America, EAB has killed millions of ash trees in 23 states. With an estimated 900 million ash trees, Minnesota is a prime target for EAB.

To prevent the spread of Emerald Ash Borer, a state quarantine is in place for Hennepin, Ramsey, Winona, and Houston counties. This means any ash material (trees, logs, branches, chips, mulch, etc) and all hardwood (non-coniferous) firewood is not to be transported outside these three counties. This material may enter the quarantined counties and travel within them; however, once inside the quarantine, it is not allowed to leave.

The metallic-green adult Emerald Ash Borer beetles are a half inch long and are active from May to September. Signs of EAB infestation include one-eighth-inch diameter D-shaped exit holes in ash tree bark and serpentine tunnels packed with sawdust under the bark.

Tips

Gypsy moths, from the butterfly and moth family, are considered by many experts to be the single most destructive pest of trees and shrubs. They were discovered in Golden Valley, St Louis Park, and Minneapolis in fall 2001. No more have been found in that area since the Minnesota Department of Agriculture treated 1,850 acres in May 2002. However, 58 acres were treated for an infestation in Brooklyn Park in 2006.

By 2013, Minnesota was mostly in the pre-infestation area. The Arrowhead region and a few counties in extreme southeastern Minnesota are in areas where low-level moth populations are present. Targeted treatments are used to slow the spread of this pest. In northeastern states, the caterpillars have defoliated and destroyed whole forests, lowered property values, and absorbed huge investments by governments for control.

Containing these invaders is not easy. Immobile but fertile female moths deposit eggs everywhere, including vehicles, camping equipment, etc. These tan egg masses spend most of the year waiting for a ride from unknowing creatures, including humans. When the eggs become larva (caterpillars) in May, they do major damage feeding day and night for about six weeks. Watch for their bright yellow heads and brown bodies lined with pairs of five blue and six red spots along the back. The adult male moth is medium-sized with brown wings and, unlike many moths, flies during the day. The female is generally white and does not move. If you see a white, flying moth, it is not gypsy moth.

If you see gypsy moths in any life stage or even suspect a gypsy moth infestation, report it immediately to 651-201-MOTH or 1-888-545-MOTH.

For more gypsy moth information, visit the Minnesota Department of Agriculture's Gypsy Moth Unit.

These diseases are caused by fungi carried by an insect from tree to tree. Once the fungus takes hold, it grows rapidly in the water-conducting vessels of the entire tree. The vessels clog and the tree wilts and dies. The diseased tree then becomes a breeding site for more insects that will transfer the disease to healthy trees.

Dutch elm and oak wilt diseases are continuing problems within Golden Valley's urban forest. Over the past several years, the City has experienced losses to Dutch elm disease. With thousands of elm and oak trees remaining in the city, continuation of a comprehensive sanitation program is essential to keeping annual losses to a minimum.

Symptoms

The first sign of the disease is the wilting of one or more branches in the upper part of the tree. Affected elm leaves turn dull green to yellow, then curl and sometimes fall to the ground. The disease progresses down the infected branch and into the main trunk. A certified tree inspector can positively identify Dutch elm disease by obtaining a wilted branch and peeling back the bark to expose the tissue.

How the Diseases Spread

Both Dutch elm and oak wilt disease are spread two ways: overland transmission via an infected beetle and underground transmission through common root systems of like species. Elm bark beetles breed in diseased trees and in recently cut (non-diseased) firewood. They become active in April and fly from tree to tree, introducing spores of the fungus into healthy elm trees.

The picnic beetle that carries the oak wilt fungus needs an open wound (such as a pruned branch) to infect a healthy tree. Oak wilt is transmitted through root grafts or by fungal spores on the diseased tree that attract beetles This beetle is active in April, May, and June, when the tree is susceptible to infection. Never prune your oaks during those months. The safest time to prune elm and oak trees is late winter, before April 1.

Firewood

Recent trimmings from elm trees, whether the tree was healthy, diseased, or died from another cause, provide excellent breeding locations for the elm bark beetles that spread Dutch elm disease. These beetles breed in any dead elm wood where the bark is intact.

If you have any firewood or branches obtained from trimming or storm damage, check it for green elm wood. If you find any elm wood with the bark intact, it must be destroyed (burned), debarked, or removed by April 1. The wood cannot be safely stored in a garage or indoors.

Prevention

To decrease the chance of infection, do not trim oak and elm trees during the growing season (April 1 through September 30). Accidental wounds to oak trees during April, May, and June should be covered with shellac or water-based (latex) paint.

Disease Management Policies

Each June, July and August, the City conducts inspections on public and private property to detect diseased elm and oak trees. If you suspect that trees on your property have problems, report them as soon as possible. If you have a diseased tree, see Condemned Tree Removal Q & A.

Removing Diseased Trees

Who is responsible for removing condemned diseased trees?

The City is responsible for removing trees from public property within 20 days of disease confirmation. Property owners are responsible for removing condemned trees from private property.

What are the regulations regarding tree removal from private property?

State and City regulations require you to cut down marked trees and properly dispose of all portions. Removal must be completed within 20 days of disease confirmation.

How do I get my tree removed?

The City of Golden Valley does not contract for tree removal from private property. Consequently, you have the option of removing the tree yourself or hiring a qualified tree removal service. When hiring a tree service:

  • Acquire several bids to assure yourself a fair price. Make sure the quoted price includes taking the tree down, removing it from your property, and disposing of it properly. Stump removal is not required if it is debarked. Request proof of insurance (both liability and worker's compensation) from the contractor.
  • Ask for recent references and check them to determine contractor ability and quality of work. Check with the Better Business Bureau as well.

What happens if I do nothing about removing my condemned tree(s)?

If no action is taken by the property owner after 20 days following notice of removal, the City will issue a "Forced Removal Notice" and have the tree(s) removed. The cost of removal, plus an administrative surcharge, will be assessed against the property owner's tax liability.

Can I store elm wood on my property?

A property owner may NOT store elm wood unless all of the bark has been removed. If the stump is not removed, all above-ground portions must be debarked. These restrictions apply to all elm species.

 

Trees & Legal Concerns

If you feel a neighbor's tree conflicts with the use of your property, the first step should always be to talk to your neighbor. If you can't reach a reasonable agreement, consider using a mediation service.

To learn more about trees and the law, read:

Managing the Urban Forest

Trees are major capital assets in America's cities and towns. Just as streets, sewers, public buildings, and recreational facilities are part of a community's infrastructure, so are publicly owned trees. The entire urban forest is an important asset that requires the same care and maintenance as other public property.

Five elements are necessary to gain the maximum benefits from the planned care of city trees:

  • Planting is needed to replace trees and fill treeless spaces. A forestry program ensures that only quality trees are used and are expertly matched to the site and growing conditions to prevent future problems.
  • Watering is a must to encourage establishment, prevent stress during droughts, and help trees resist insect and disease attacks.
  • Pruning results in high dividends of safety, resistance to storm damage, improved visibility of signs, and in shaping and growing beautiful, useful trees. Proper pruning requires knowledge and skill.
  • Pest control is necessary to monitor ever-present diseases and insects and provide regular, preventive care and prompt action if an epidemic should break out.
  • Tree removal, when necessary, must be done in a responsible, safe manner. However, the bottom line of urban forestry is to extend the lives of trees.

The City Forester

Community foresters plan and supervise the special, intensive care needed to guarantee the future of trees growing under tough conditions of the urban environment—pollution, poor soils, scorching heat, restricted roots, road salt, construction damage, vandalism, and a host of insects and diseases. They are trained to view trees collectively and to manage them as an ecosystem, considering specific biological, social, and economic conditions. This broad view enables the community forester to help taxpayers make wise decisions and get the most from their investment in trees.

City foresters play a vital role in the health and future of these trees. Specifically, a City forester can:

  • provide you with valuable, localized information about tree care and how to comply with tree ordinances
  • make sure your tax dollars are spent wisely on trees of good quality
  • work with City engineers to protect and replant trees during road construction or street improvement projects
  • manage tree diseases within the community