Tree Management Tips for Homeowners

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

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

Trees For Sandy Soils

• Bur Oak
• Cedar
• Ginko
• Hackberry
• Hawthorn
• Honeylocust
• Junipers
• Pines
• Redmond Linden

Shade Tolerant Trees

• American Linden
• Arborvitae
• Balsam Fir
• Chokecherry
• Japanese Tree Lilac
• Maples
• 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 (i.e., will it survive in winter)? When the tree is full-grown, will it 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 about proper care, 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.

Additional Resources

• MN DNR: Prepare and Plan for Tree Planting

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 4 or 5 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 or elms in April, May, or June.
• Always remove 100 percent of the deadwood but never more than 25 percent of the live wood on young trees, and less for mature trees.
• 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 spring and fall 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 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 prune. 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.

Additional Resources

• University of MN Guide to Pruning Trees & Shrubs

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 5-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. Stem girdling roots can also result from planting too deep.

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 or elms are wounded in April, May, or June, wound dressing may help prevent the insects that can carry disease fungus from transferring the disease to your tree.

Additional Resources

• University of MN: What's Wrong With My Plant?
• MN DNR: Caring For Trees 

Hiring a tree care 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.