Winter-2006 by Minnesota Shade Tree Advisory Committee

Vol. 8, No. 1

Winter 2006

COMMUNITY FOREST PROFILE

SPRUCE UP AUSTIN, M By Lee Bonorden

pruce Up Austin (SUA) is deeply rooted in Austin’s future. Created 15 years ago by a small group of concerned citizens, SUA has grown to become a fixture in the community. The premise is simple: volunteers discuss a possible project, involving trees, for community enhancement. The project must take place on public property for all to enjoy. With permission from Austin city officials, the organization utilizes the skills of the Austin Parks, Recreation and Forestry Department as well as local nursery and landscaping expertise to create a plan. Then, the project is undertaken. A day of work is scheduled and volunteers recruited. The volunteers have routinely been inter-generational and frequently include Austin High School students.

KELLY LADY

innesota

SUA board members present the Yard of the Month recognition to September winners. Pictured from left to right are Don Wagner, Bonnie Mogen, Jan Chuick, YOTM winners Bill and Pat Schmidt, and Kelly Lady.

On any project Saturday, volunteers do the work - on hands and knees - with their own tools. When the project is finished, the bills are paid, all by donations, and SUA plans the next community betterment project. Milestones are many in the organization’s history. The projects can also be fun and significant. For example, 100 trees were planted along a city street renamed “Hormel Century Parkway” to celebrate the 100th anniversary of Hormel Foods Corporation. And, at 12:01 a.m. on Jan. 1, 2001, volunteers planted the first tree in Austin in the new millennium.

Inside This Issue 2 Perspectives Column 4 Dispel-A-Myth: Sterilized Pruning Equipment: The Myth of Chlorinated Clippers

Honorary Tree Program

6 Urban Forest Health: Will Fill Kill?

The single-most popular tree planting location is the area known as the Mill Pond Pathway in Horace Austin Park along the banks of the Cedar River. Over 200 trees have been planted there, making it the jewel of the city’s parks system.

12 Green Streets, Not Mean Streets

10 Clip & Save: Pesticides

Spruce Up Austin continued on p. 3

13 Will the Pines Still Be Green Next Spring? 15 STAC Info and Calendar

Visit MnSTAC on the Web at www.mnstac.org

The Minnesota Shade Tree Advisory Committee’s mission is to advance Minnesota’s commitment to the health, care and future of all community forests. ADVOCATE • Winter 2006

PERSPECTIVES COLUMN

Eagan’s Grandfather Tree Tells His Story By Kay Brown Gustafson

The oldest and largest tree in the state of Minnesota that has been moved now has his own storybook: Aunt Gussie and Grandfather Tree. The story was created from my own real-life experiences. As Chair of the Grandfather Tree Project in Eagan, Minnesota, I worked to save the 150-year-old bur oak tree. The 45-foot-tall, 250 ton tree needed to be removed to clear the way for road access to a new community center.

It provides a new paradigm that can be appreciated by children and adults: not all trees in harm’s way need to be destroyed.

Aunt Gussie and Grandfather Tree had its first reading at the Minnesota Shade Tree Short Course at Bethel College in 2002. Since that time, I worked with artists Patrick Rolo and Lisa Fifield to create a beautifully illustrated 48page children’s picture book. Although the book is a fictionalized account of the actual events, the message is clear: people working together can make a difference in preserving trees in their communities. The story symbolizes the challenges faced by many communities across the nation. How do we protect the natural world in the wake of development? It provides a new paradigm that can be appreciated by children and adults: not all trees in harm’s way need to be destroyed. My hope is that this book will be used as a teaching tool. Because it is written at a third grade level, it is easy to read aloud. Children can relate to the 10 year-old character, Gloria, and her attachment to a favorite tree. The book can be an excellent resource for school visits on Earth Day and Arbor Day. At the

end of the book, there is a link to the City of Eagan’s Department of Forestry, so the readers can learn more about the Grandfather Tree. The Grandfather Tree Project itself received national attention. It was featured in the National Arbor Day Foundation’s Tree City USA Annual Report and received the Treescaping Award from the Minnesota Society of Arboriculture and the Minnesota Recreation and Park Association’s Award of Excellence. The project generated media attention from National Public Radio, as well as major media in Minnesota. “Grandfather Tree” as he is affectionately called, was moved 450 feet to the entrance of Eagan’s community center. Greg Hove, Forestry Supervisor for the City of Eagan, was also instrumental in the project. He reports that the Grandfather Tree, now just completing his fifth year since being transplanted and preserved, is well on the way to complete recovery. This recovery period is expected to last for several more years - but this beautiful, large bur oak tree continues to produce new roots and an even crown of new leaves each year, allowing it to absorb much needed energy for future growth. Kay Brown Gustafson is the author of Aunt Gussie and Grandfather Tree. The book is available through local bookstores or at www. grandfathertree.org.

Winter 2006 • ADVOCATE

Spruce Up Austin from p. 1

Project Partners

KELLY LADY

Spruce Up Austin does not ignore any of its planting projects. SUA volunteers and our “partners” work together on a regular basis to maintain Volunteers help plant 42 trees along Austin’s bike path. Pictured are Mary Svoboda, Jenna community Svoboda, Taylor Lady, Dylan Svoboda and Craig Lady. projects. World War II and Horace Austin Park is also a popular site other veterans have worked with SUA for the SUA Honorary Tree Program. For a volunteers to restore Austin’s Honor donation, a tree is planted to honor a loved one. Guard Park. School children have A registry notes the trees and loved ones who are helped SUA workers cleanup school honored with the plantings. What better legacy to property and roadsides. High school leave than a tree that grows for decades? athletes and at-risk youth have planted trees along a boulevard leading into Yard of the Month the city. Partnerships with Austin Park and Recreation, Austin Chamber of Spruce Up Austin has also created the Yard Commerce, and Austin Utilities have of the Month recognition program. Each month resulted in an increased awareness of - May through September - SUA recognizes the importance of trees to both the residents who have enhanced their yards with environment and to energy conservation. trees, shrubs and flowers. The recognition program has inspired residents themselves to Future Plans become deeply rooted in Austin’s future. One improved yard in a single neighborhood becomes Next year, 2006, is the City of the living catalyst for other yard improvements Austin’s sesquicentennial. What is Spruce throughout the city. Up Austin planning? How about planting 150 oak trees to celebrate the 150th This past summer, SUA hosted it’s first-ever birthday and inviting residents to plant yard and garden tour of the city. Past winners of their own trees? What a great idea! the Yard of the Month recognition program were Lee Bonorden is a Board Member of Spruce Up featured. The Saturday morning fund-raiser was Austin Inc. a popular event, attracting over 200 visitors. The exchange of information and ideas between the

“Spruce Up Austin has so many hardworking and dedicated volunteers. I get pleasure from working on SUA’s beautification projects and then watching the plants grow and mature and become even more beautiful over the years.” – Kelly Lady, President of Spruce Up Austin Inc.

KELLY LADY

host gardeners and their guests will hopefully inspire more residents to plant trees and gardens.

Learn more about Spruce Up Austin by visiting their website at

www.spruceupaustin.austincoc.com

ADVOCATE • Winter 2006

DISPEL-A-MYTH

Sterilized Pruning Equipment: The Myth of Chlorinated Clippers By Patrick Weicherding

The Myth: “A household chlorine bleach solution is the best choice for sterilizing pruning tools.”

disinfectant materials than common household chlorine bleach.

Professional arborists, as well as many tree health care practitioners, spend thousands of dollars on top-quality pruning equipment. It makes sense that they would want to clean and maintain these tools on a regular basis. This practice becomes even more crucial if they are worried about potentially transmitting plant diseases such as fire blight, Dutch elm disease, and sudden oak death. The question is – how often should you clean your equipment and what should you use as a disinfectant?

According to Dr. Chalker-Scott, the use of chlorine bleach for disinfectant use in tree health care is not recommended for a variety of scientific and practical reasons: 1. Tool damage. The MSDS (Material Safety Data Sheets) for Clorox® and other brands of bleach states: “Prolonged contact with metal may cause pitting or discoloration.” This includes pruning tools. Bleach is an oxidizing agent, which means it is corrosive. That’s why you can’t purchase bleach in unlined metal containers. It is only for sale in certain types of plastic bottles.

A standard recommendation found on nearly all popular web sites dealing with pruning trees and shrubs says something like this: “To prevent the dispersal of 2. Clothing damage. [disease] material from infected Chlorine bleach literally “bleachbranches to healthy branches, es” or removes the color from pruning tools should be sterilized clothing. Any accidental exposure between cuts with a 10% bleach in the field is impossible to treat solution.” This advice is repeated unless you soak the affected matein hundreds of university fact Sterilizing tools will prevent the spread rial immediately in water. Rags sheets, government brochures, and of diseases. used to wipe your equipment reference books. While this advice down after treatment will disintemay seem to be intuitive, especially with regard grate quickly. You’ll have to replace them continuto the spread of infectious diseases, one has to ask ously. – is a household chlorine bleach solution the best choice? 3. Human health issues. Chlorine bleach is listed as an acute and chronic The Reality health hazard. Direct contact with bleach will irritate your skin and your nose, throat and lungs A number of years ago, Dr. Linda Chalkerif you inhale the vapors. Medical conditions such Scott, an Extension Horticulturist and Associate as asthma, chronic bronchitis and obstructive lung Professor from the Puyallup Research and disease are aggravated by exposure to chlorine Extension Center at Washington State University, bleach. Using bleach to disinfect pruning tools wrote a fact sheet on whether or not it was will likely be done outdoors or in a well-ventilated necessary (or simply a nuisance) to sterilize area, but you should also minimize your health pruning tools. Based on her review of the scientific risk by wearing impervious gloves and safety literature that addressed this issue, she concluded glasses. that although sterilization is not a necessary practice for all diseases, there are appropriate 4. Plant health injury. times with specific pathogens to legitimize Bleach is extremely phytotoxic (literally, poisonthe need to disinfect pruning equipment. She ous to plants), more so than any other commonly also concluded that there are better choices of used disinfectants. Bleach residue left on your dis-

Winter 2006 • ADVOCATE

A number of disinfectants have been used or recommended as a better alternative to chlorine bleach for disinfecting pruning tools. They include: • Alcohol dips (ethanol or isopropyl alcohol; 70% solution): Alcohols are readily available and moderately safe and effective to use. Their biggest drawbacks is that they can be expensive if purchased in small quantities and difficult to obtain in large volumes. • Alcohol dips + flaming: This is a standard procedure for tissue culture in the laboratory but it’s not very practical for field use. • Copper compounds (copper oxide, Bordeaux mixture): Copper-based fungicides have been have been around for hundreds of years, but there is not a great deal of research on their effectiveness as pruning tool disinfectants. They are readily available but probably not the most environmentally friendly choice. Copper sulfate (Bordeaux mixture), for example, is caustic and acutely toxic particularly to fish. • Formalin (HCHO): Formalin is a mixture of formaldehyde and methyl alcohol. It is used in embalming fluid and readily penetrates skin. While formaldehyde is a potent disinfectant and anti-bacterial agent, it is essentially ineffective as a fungicide. Not a good choice for disinfecting pruning tools. • Household cleaners (Listerine, Lysol®, Pine- Sol®): Readily available, moderately safe and can be extremely effective. Lysol® in particular was found to be the least corrosive to pruning tools. (This is Dr. Chalker-Scott’s personal choice). • Trisodium phosphate (Na3PO4; 10% solution): Much like household bleach, this compound is very corrosive and probably not a good choice for field application. ADVOCATE • Winter 2006

To disinfect your pruning tools or not – what’s the bottom line? According to Dr. Chalker-Scott, you can use the following guidelines to make an informed decision about when, why, and how to sterilize pruning tools: • If it’s a virus or viroid (microscopic infectious agent, much smaller than a virus, that infects higher plants), disinfect your tools. • If it’s a vascular fungus (Dutch elm disease and oak wilt) or bacteria (fire blight), and/or forms oozing cankers, disinfect your tools but avoid cutting active, oozing cankers until they are dry. • If you are pruning irreplaceable plants, disinfect your tools. • If you decide to sterilize your pruning equipment, choose a disinfectant treatment that has been shown to be effective through published research. The disinfectant should be readily available and affordable, relatively safe to handle, and won’t harm your tools, clothing, or the environment. Many household cleaners like Lysol® fit this description. Finally, in regard to your pruning tools, keep the following in mind: • Be sure to clean tools of dirt, debris, etc. before disinfecting, so the disinfectant can reach every cutting surface. • After dipping your pruning tools, be sure to wipe away excess disinfectant to avoid injuring the next plant. Remember, most disinfectants are phytotoxic to plants and cause more harm than good. • A longer soaking may be needed for pruning tool surfaces that are not smooth. The older the cutting surface, the more pitted it becomes; these pits can harbor microbes that are unaffected by quick sterilization. This is especially true of bacteria associated with active cankers.

http://www.puyallup.wsu.edu/~Linda%20Chalker-Scott/Fact%20sheets.html

Alternative Disinfectant Treatments

The Bottom Line

The complete text of Dr. Linda Chalker-Scott’s fact sheet can be found at

infected pruning tools will damage the plant tissue next to the cut and cause more harm than good. For this reason, bleach is no longer an acceptable disinfectant for use in sterilizing pruning wounds, especially those made on diseased trees and shrubs.

Patrick Weicherding is a Regional Extension Educator and Professor with the University of Minnesota Extension Service.

• Like pruners, increment borers and drill bits should always be sterilized before and after use.

URBAN FOREST HEALTH

By Rebecca Koetter and Gary R. Johnson

The truth about adding soil over the roots of existing landscape trees.

o, the title “Will Fill Kill?” has nothing to do with people’s propensity to stuff digestive systems during Thanksgiving! Instead, it directs attention to the common questions of homeowners’ about relandscaping and construction activities around their trees: • What is fill soil? • What are the potentially harmful effects on tree roots and tree health? And, • Are there options available to avoid harming trees? Fill is a term commonly used by building contractors, landscape architects and designers that refers to the addition of soil or other materials (e.g., sand, gravel, debris) to raise the level of a landscape. Fill is strictly a physical change and is not normally a method to improve soil nutrition, aeration or moisture movement. Fill is used to level out irregular landscapes. It’s used to fill up larger depressions that may be the results of settling soils or previous excavations. Or, fill may be used to create a foundation for sidewalks, patios or driveways. Fill (sometimes referred to as misplaced soil) can be any sort or mixture of mineral materials (from large rocks to sand), soil (from clay to silt) or debris (bricks, concrete, or other artifacts). Often, it’s a random concoction of these elements: mixes of soils, clay and gravel, chunks of concrete mixed with clay and sand. Organic matter that does add nutrition to inert soils is generally not part of fill soils. The point is, fill soil is an unreliable part of the landscape and in areas where it’s part of newly constructed areas it quite often alters water movement and contributes to unacceptable compaction levels (Day, 1999). When a significant amount of fill is added to a landscape, soil conditions will change, as will the root growth potential of existing trees. It has been estimated that 80-90% of all tree problems are related to soil and its effects on root growth potential and health of the trees’ entire root systems (Smiley, et al, 1998).

A primer on tree roots.

Overall, tree root systems are often misunderstood. Many believe that tree roots extend tens or scores of feet deep into the ground, and those trees have one moisture-seeking tap root that reaches the water table. However, most

Winter 2006 • ADVOCATE

trees have a short tap root stage of life and most roots are within the top three feet of the soil. In addition, fine roots (those that absorb most of the water and nutrients from the soil) are found within the top 12 inches of the soil (VanDerZanden, et al, 2001). Research has revealed that as little as four to six inches of fill, placed over the roots of some tree species, have caused serious life-damaging conditions (University of Rhode Island, 2005), yet Seven Feet of fill placed over the roots of one tree caused no apparent damage (Costello, et al, 2004). How can this be?

Table 1: Soil Fill by Texture Class than can be added with varying degrees of effects on root health. Soil Texture Class

Fill alters air, nutrient and moisture situations. However, research has shown that these situations may or may not be solely responsible for tree damage. Table 1 shows the variability of effects on tree root health based on fill texture and depth. Other factors that are at least as important as the quality and depth of fill include the tolerance of the existing trees: tree species, tree age and overall tree health. In general, these factors moderate or aggravate the effects of fill: • Species with a vigorous growth habit (e.g., red maple, green ash) and those that survive in wetter environments may grow rapidly enough to recover from the fill event (Table 2). • Younger trees recover from damage quicker than older trees of the same species. And, • Trees in good health respond better to injury than trees in poor health of the same species (Costello, et al, 2004)

Massive root damage by soil fill (inches)

Sand

Fine sand

Sandy loam

Fine sandy loam

Loam

Silt loam

1.5

4.5

Clay loam

1.5

4.5

Clay

Coder, Kim D. 1996. Construction Damage Assessments: Trees and Sites. University of Georgia.

Table 2: A Partial Listing of Trees that are more likely to survive the addition of fill over their root systems. Tree Species

Relative Tolerance

Northern White Cedar (Thuja)

Good

Tamarack (Larix)

Good

Green Ash (Fraxinus)

Fair to Good

River Birch (Betula)

Good

Catalpa (Catalpa)

Fair to Good

Eastern Cottonwood (Populus)

Good

Red and Silver Maple, Boxelder (Acer)

Good

Bicolor Oak (Quercus)

Fair to Good

Black and White Willow

Good

Black Spruce (Picea)

Fair to Good

More than the Fill, more than the Trees.

In addition to the obvious factors, namely, the fill and the trees, there are still more factors to consider. The soil composition (i.e., the texture as well as the structure) of the original landscape – also called the base soil - is very influential on a tree’s tolerance, and the amount of the tree’s root area that will be directly impacted by the fill (Tusler et al, 1998). Base soils that are more prone to compaction can aggravate the detrimental effects of fill because the existing tree roots are growing in the base soil. Finer textured base soils – such as silts and clay soil – are more vulnerable to compaction by the equipment that brought in and spread the fill soil (e.g., trucks and tractors). The mere weight of six inches of fill is often enough to significantly compact a vulnerable base soil.

Initiation of root damage by soil fill (inches)

Johnson,Gary R., 1999. Protecting Trees from Construction Damage. University of Minnesota Extension Service.

Will Fill Kill? continued on p. 8 ADVOCATE • Winter 2006

Will Fill Kill? from p. 7 The texture and structure of the fill soil compared to the texture and structure of the base soil can determine the amount of water that will reach existing tree roots. A coarse textured fill over a compacted, fine textured base soil (or vice-versa) can result in a situation that makes it very difficult for both oxygen and moisture to uniformly penetrate the soils where the tree roots currently exist and where they need to grow.

Is it a tree worth saving, a battle worth fighting?

With this information on the effects of varying depths and textures of fill soil, varying textures and structures of base soils, and a tree’s relative tolerance to changes, the next step should be a determination of whether the tree or trees in question are worthy of preservation and protection tactics. Diseased or dying trees should be removed simply because the chances of a tree surviving in that condition are slight. Removing those trees would open up space for new trees after the filling operation is over. However, if the tree is relatively healthy and is a key element in the looks and function of the landscape, and if money is not an issue, then all necessary steps to save the tree may be taken.

Preventing damage from fill.

The decisions have been made: fill will be added, but fill must not kill! Nothing is absolute, but the following tactics have successfully accomplished both and are most effective when all tactics are used. Minimize the amount of roots covered. Tree “wells” can very effectively protect existing tree roots from being smothered by fill…IF they are constructed in the right place. At a minimum, locate the wells as near as possible to the dripline (the edge of the branch spread) of the tree. As research has shown with tree wells, the larger the well, the better (Costello et al, 2004). A tree well constructed directly around a tree trunk or within a few feet isn’t much more than a very attractive brick coffin. Often, tree wells will need drainage holes or pipes if the fill is very deep and/or if standing water problems are to be avoided. Choose fill wisely. Tree health will be determined by the amount of fill used and the ability of the tree roots to grow into the newly added fill. Use the least amount of fill that is absolutely necessary. Choose fill that is less damaging to roots (Table 1). Select fill that has a similar texture to the base soil. Better conditions for tree health are achieved when only a small portion of the roots are affected and the fill soil is similar in texture to the base soil (Costello et al, 2004). Take care of the base soil. Avoid driving heavy equipment over the base soil, especially during the times of the year when the base soil is thawed and moist. This is the period when soils are most vulnerable to compaction, and finer textured soils such as clays can be irreversibly compacted. If you must use heavy equipment, do the grading when the base soil is frozen or very dry. If you can’t do the filling during those times of the year, apply the fill with the long arms of a backhoe and then grade it.

As a general rule, it is cheaper and more effective in the long run to prevent damage from taking place. Research has shown that little success can be expected by removing fill that has been present around the tree for more than two years (Cue et al, 2002). The initial costs may be high, but time, energy and money will be saved if proactive actions are taken.

Aeration systems and layers of coarse gravel under the fill may not help at all. There is little research-based evidence that aeration systems under fill soils are consistently effective, and they are very expensive. Likewise, coarsely ground rock layers that separate base soils from fine textured fill soils may restrict water movement by creating a layered stratum that does not allow normal water percolation. The above tactics would be expensive with good intentions; however the benefits would be marginal and the chances that more damage could result are high. Winter 2006 • ADVOCATE

References: Coder, Kim D. 1996. Construction Damage Assessments: Trees and Sites. University of Georgia. Costello, L.R. and Susan D. Day. 2004. A New Look at the Impact and Management of Fill Soil around Trees, pp. 25-29. Arborist News. August 2004. Cue, K.P., S. Josiah. 2002. Landscaping around established trees. Retrieved June 15, 2005 from NebGuide Website: http://ianrpubs.unl.edu/ forestry/g1452.htm. Day, Susan. 1999. Growth and Physiology of Several Urban Tree Species in Soils Disturbed by Construction Fill or Compaction. Dissertation submitted to the faculty of Virginia Polytechnic Institute and State University. Johnson, Gary R., 1999. Protecting Trees from Construction Damage: A Homeowner’s Guide. University of Minnesota Extension Service, FO-6135.

In Summary

Many existing trees are unwittingly lost due to filling operations associated with new landscapes and construction activities. This doesn’t always need to happen if a few simple steps are followed: 1. If the tree is priceless, irreplaceable… don’t fill. 2. If the tree is worth saving and has a chance of making it (i.e., good genes, younger, healthier), then continue with the following steps. KEEP that tree healthy during and after the fill operation. 3. Choose a fill that will be less restrictive to water and oxygen from Table 1 (e.g., a sandy loam is better than clay). 4. Choose a fill that has a similar texture to the base soil. 5. Apply the least amount of fill necessary. 6. Affect the least amount of the root system as necessary. If possible, construct a well that will keep fill away from the roots of the tree.

ADVOCATE • Winter 2006

7. Do not compact the base soil during the fill operation. Avoid heavy equipment use, especially during times of the year when the base soil is wet. 8. Finally, because so many considerations and assessments must be done in order to save and keep trees healthy, it may be worth your time and money to have a professional who is a specialist in tree preservation assess and monitor the entire fill project.

Rebecca Koetter is a Graduate Research Assistant in the Department of Forest Resources, and Gary R. Johnson is a Professor of Urban and Community Forestry in the Department of Forest Resources, University of Minnesota.

Smiley, E.T., T.R. Martin and Bruce R. Fraedrich. 1998. Tree root failures. Landscape Below Ground II: Proceedings of an International Workshop on Tree Root Development in Urban Soils. D. Neely and G. Watson, Eds. International Society of Arboriculture, Champaign, IL. Tusler, P.E., J.D. MacDonald and L.R. Costello. 1998. Fill soil effects on soil aeration. Landscape Below Ground II: Proceedings of an International Workshop on Tree Root Development in Urban Soils. D. Neely and G. Watson, Eds. University of Rhode Island, (n.d.). Maple Tree Decline. Retrieved June 16, 2005, from Greenshare Factsheets Web site: www.uri.edu/ce/factsheets/ sheets/mapletreedecline.html. VanDerZanden, A.M. and J. McNeilan. 2001. Conserving Water in the Garden: Landscape and Lawn Care. Retrieved June 16, 2005 from Orgeon State University Extension Service Website: http://eesc.orst. edu/agcomwebfile/EdMat/html/EC/ EC1531/EC1531.html.

Get My Dr i

Legal Aspects of Pesticide Drift t f

By Lorrie Stromme

very year, nearly 5 billion tons of pesticides are intentionally applied to the American landscape.1 Responsible pesticide use is critical to avoid adverse environmental impacts. At the neighbor-to-neighbor level, the issue can become contentious when pesticides drift from one neighbor’s yard to another. The following answers address homeowners’ most commonly asked questions about pesticide drift.

1. What is a pesticide?

Pesticides 10

Federal law defines a pesticide as any substance intended for “preventing, destroying, repelling, or mitigating any pest,” and substances intended for use as a plant growth regulator, defoliant, or dessicant. 2 The word-ending “cide” means “killer.” The term “pesticide” is a general term and includes insecticides (killer of insect pests), herbicides (weed control), fungicides (fungi control), rodenticides (mice/rat control), etc.

its target and land on non-targeted plants. Drift becomes a problem when the herbicide or other pesticide has an unintended impact or causes damage. An example is 2,4-D, a herbicide used to control dandelions and other broadleaf weeds. Some lawn-care products (e.g., Ortho Weed-B-Gon and Scotts Turf Builder with Plus 2 Weed Control) contain 2,4-D. The granular form of 2,4-D can turn into a gas and drift away from the place where it was applied, harming plants sensitive to 2-4-D, like grapes, tomatoes, and lilacs. 3

“My experience has taught me that by far the best way to resolve or prevent drift disputes is for the two parties to discuss the situation as adults in an open and respectful manner.”

3. How can pesticide drift be prevented?

Preventing spray drift is the responsibility of the person applying the pesticides. (Applicators include private citizens, farmer/ growers, commercial applicators, and noncommercial applicators.) Using common sense is the best means of Professor Dean Herzfeld, prevention. Mix and apply pesticides only coordinator of the Pesticide when winds are calm Applicator Training Program (less than 10 mph). Most in Minnesota. important, read the label on the pesticide before using it, and follow the directions. The label is the law. All of the label directions are the legal requirements for using the pesticide safely and 2. What is pesticide drift? effectively. Pesticides must be applied correctly Pesticide drift is the movement of to avoid collateral damage. Pesticide labels are pesticides through the air, away from the not an easy read; they take some time to review area where they were applied. It’s somewhat and understand. But it’s time well spent … to use analogous to secondhand smoke. Cigarette pesticides responsibly and to stay on the right smoke drifts away from the smoker and side of the law. Pesticide labels can be found the can be inhaled by nearby non-smokers as internet, if the label attached to the product is hard secondhand smoke. Similarly, a herbicide to read. 4 sprayed on a plant or tree can drift away from

Winter 2006 • ADVOCATE

Pesticides can be used only on the sites, plants, or crops listed on the label. The label also specifies the application rate and method, storage and disposal information, protective clothing to wear while using the pesticide, and environmental hazards (e.g., “toxic to bees”).

4. Will the vegetables and fruits in my garden be safe to eat?

If a pesticide that drifts onto your vegetables or fruit is not labeled for use on vegetables or fruit, do not eat them. Pesticides that are labeled as safe to use on particular vegetables and fruits identify “safe” levels of pesticide residue for the food-plants listed on the label. But there is no sure way to know if a pesticide labeled for use on a non-food plant has a “safe” level of pesticide residue for a non-target plant. For example, a lawn herbicide can be used on turf, but the label does not identify a safe level of herbicide residue on fruits and vegetables, because they are nontarget plants. If you are uncertain, don’t eat the affected fruit and vegetables.

5. What can I do if my neighbor uses a pesticide that damages my plants or property?

In Minnesota, it is illegal to apply a pesticide that strays onto the adjacent property and causes damage. 5 In fact, in Minnesota pesticide drift is illegal even if there is no damage. “A person may not direct a pesticide onto property beyond the boundaries of the target site,” according to the law. 6 Taking your case to court for the loss of garden plants is not a good option. Most of the cases that have ended up in court involve aerial spraying of acreage (crops or forests) and significant monetary losses. The “garden variety” dispute between neighbors is usually not taken through the trial and appeal process, because of the financial realities of paying for lawyers, expert witnesses, scientific analysis, and other litigation costs. The challenge is proving what pesticide did the damage and the connection between the pesticide that drifted off-target and the damage done. Scientific analysis for pesticide residue is costly (usually several hundred dollars.) The University of Minnesota Extension Service no longer has a clinic or other means to diagnose pesticide drift or herbicide damage in home landscapes. The Minnesota Department of Agriculture (MDA) oversees pesticide use in the state. But the MDA investigates complaints only

ADVOCATE • Winter 2006

when it suspects that there is a violation of the law. Priority is given to investigations involving injury/ damage to humans, animals, food/feed products, and the environment. The MDA receives complaints at 651-296-6121. The complaint process is explained online at http://www.mda. state.mn.us/appd/pesticides/complaints.htm. The recommended option is to try the neighborly approach. “My experience has taught me that by far the best way to resolve or prevent drift disputes is for the two parties to discuss the situation as adults in an open and respectful manner,” maintains Dean Herzfeld, a University of Minnesota Associate Professor and Extension Educator in the Plant Pathology Department, and the Coordinator for the Pesticide Applicator Training Program in Minnesota. Speak to your neighbors in a friendly, tactful way and explain your concerns about the impact that their pesticide use has had on you, your health, your garden, or your pets. Try to negotiate a solution that satisfies both of you. Find out what pest problems your neighbors are having and provide constructive information about nontoxic, pest-control methods. For instance, if your neighbors use a product containing 2,4-D to control dandelions and it drifts onto your tomato plants, you could provide information about corn gluten meal, an organic alternative for control of dandelions and other broadleaf weeds. 7 Take a tip from the experts: Use the neighborly approach to deal with your drift disputes and preserve harmony in your neighborhood.

Timothy Kiely, David Donaldson & Arthur Grube, Ph.D., Pesticide Industry Sales and Usage: 2000 and 2001 Market Estimates, at 10 (Biological and Economic Analysis Division, Office of Pesticide Programs, Office of Prevention, Pesticides, and Toxic Substances, U.S. Environmental Protection Agency, May 2004.). 2

See 7 U.S.C. § 136 (u) 3

Herzfeld, D, B. Jarvis, The Considerate Gardener’s Guide to Pesticides, Part 2. Yard & Garden Line News, September 1, 2003. http://www. extension.umn.edu/ yardandgarden/YGLNSept0103.html 4

See, for example: http://www.cdms.net/ manuf/default.asp. 5

“A person may not apply a pesticide resulting in damage to adjacent property.” Minnesota Statutes §18B.07, Subd. 2.3 (b).

Lorrie Stromme is a lawyer who practiced law for 16 years before leaving private practice for public service, first with Hennepin County and now the City of Minneapolis. She is a past president of the Minnesota Shade Tree Advisory Committee, tree care advisor, and master gardener. She has a Master’s degree in horticulture.

6 7

Ibid.

U of MN information on corn gluten meal: http://www. extension.umn.edu/ extensionnews/2004/ gluten.html

Green Streets, Not Mean Streets By William Sullivan

the inner city, vegetation that allows for visibility seems to promote safety. Factors combine to explain this: We’re watching and we care. Green spaces bring people together outdoors. The conspicuous presence of people increases surveillance, which discourages criminals. More people outdoors means that threatening behavior is more likely to be observed. At the same time, potential criminals sense that they are being noticed and watched. The green and groomed appearance of an apartment building is itself a cue that residents and owners care about a property, and watch over it and each other.

While some studies have shown that vegetation is related to crime and fear of crime, a study in an urban neighborhood suggests the opposite. University of Illinois researchers Frances Kuo and William Sullivan tested the common wisdom that in the inner city, barren spaces are safer than green ones. They compared crime rates for inner-city apartment buildings with varying amounts of vegetation and found that the greener the surroundings, the fewer crimes occurred against people and property. Far from shielding criminals, such greenery seems to shield against them.

Why Greenery May Cut Crime No studies have been done to determine whether crime rates are actually higher in densely vegetated areas. Two studies have shown that criminals use dense vegetation such as shrubs, underbrush and dense woods to conceal their activities. Other studies have found that dense vegetation in some settings evokes fear and fear of crime, especially when it blocks views. However, not all greenery blocks views. Widely spaced high-canopy trees, flowers, grass and low-growing shrubs do not block views, shield crime or create the type of surroundings that promote fear. In

We’re calm. A large body of research indicates that time spent in nature lessens mental fatigue, inattentiveness, irritability and impulsivity—states of mind that psychologists recognize as precursors to violence. Greenery helps people to relax and renew, reducing aggression and increasing calm.

The Greenery Study The greenery study by Kuo and Sullivan was the first to use police crime reports to examine the relationship between crime rates and vegetation in the inner city. Two years of police data on property and violent crimes for 98 apartment buildings in a public housing development in Chicago were analyzed. Buildings included in the study were similar in size, number of residents and amount of common outdoor space. Chicago Police Department year-end Uniform Crime Reports were examined. The reports summarized the specific crimes that were reported for each address. Residents were predominantly African American, unemployed and receiving public assistance. They were generally uninvolved in landscaping decisions and their apartments were randomly assigned, so no relationship existed between the residents and the amount of greenery in the space outside their home. Aerial and ground-level photos of the residences’ common outdoor areas were used to record the amounts of greenery, which were then assessed and rated on a scale ranging from barren to fully covered by green tree canopy. Winter 2006 • ADVOCATE

Green Streets, Not Mean Streets Compared with apartment buildings that had little or no greenery, buildings with high levels of greenery had roughly half as many crimes (48 percent fewer property crimes and 56 percent fewer violent crimes) as buildings with no greenery. Even buildings with medium amounts of greenery had 42 percent fewer total crimes (40 percent fewer property crimes and 44 percent fewer violent crimes). Apartment buildings landscaped with greenery were clearly less crimeprone than barren ones. The results support prior studies that found that inner-city residents who live in green surroundings experience fewer quality-of-life crimes, such as littering and graffiti, as well as fewer incivilities, such as noisy or disruptive neighbors. The results are also consistent with prior studies in which people reported feeling safer in residential areas that contained greenery. Green spaces are gathering places that create close-knit communities and improve well-being— and in doing so, they increase safety. In innercity neighborhoods, tall trees and open, grassy areas that preserve visibility are recommended as potential deterrents to crime. William Sullivan is an Associate Professor in the HumanEnvironment Research Laboratory at the University of Illinois at Urbana-Champaign.

Think twice before removing trees or greenery for security reasons. Greenery that preserves visibility may promote safety. Landscape urban apartment buildings with tall trees, grass, groundcover, low-growing shrubs and flowers. Such spaces unite neighbors and may inhibit criminals. Spend time daily in the green outdoors. Doing so helps refresh the mind, and dissolve anxiety and tension. Support tree planting and tree care in the inner city. In harsh environments, a little green goes a long way.

More information on the greenery study can be found at www.herl.uiuc.edu or contact the University of Illinois at Urbana-Champaign, Human-Environment Research Laboratory at 1103 South Dorner Drive, Urbana, IL 61801, phone (217) 333-1965.

Will The Pines Still Be Green Next Spring? Protecting Trees and Shrubs from the Wicked Winters of the Upper Midwest By Gary R. Johnson Predict Winter Stress.

Winter damage, to woody landscape plants, trees, and shrubs, happens along three main fronts: Mechanical damage. Most commonly occurs when animals feed on trees and shrubs. Mechanical damage can also occur when melted snow and ice, along with cinders and other abrasive materials, splash the tender bark tissues of young trees and shrubs. Also, the weight of wet snow or ice accumulated on branches may be more than the branches can bear. Wet snow storms and ice storms – especially when accompanied by wind – can tear apart or permanently disfigure branches.

ADVOCATE • Winter 2006

Desiccation of the foliage. Desiccation is usually caused by one of three factors: sunlight exposure, wind exposure, or deicing salt spray. This is a big problem with evergreens and the darker the foliage, the bigger the problem. Imagine a sunny day in January. The sun beats down on the dark green foliage and heats it up. When this happens, the foliage transpires to cool off the surface and cells of the plant. Since the ground is frozen and water isn’t moving readily into the plant roots, sap quickly gets consumed and the leaf tissues begin to dry out. Cold temperature damage. The least cold-hardy part of most woody plants is the root system. Next Will the Pines... continued on p. 14

Will the Pines... from p. 13 in the vulnerability line would be cambial tissue, flower buds and finally vegetative buds. Cold hardiness is an inherent quality and it has a tremendous impact on whether or not there will be damage to the plant from cold temperatures. Wouldn’t it be nice if that was it? Provenance (source of the seed or cutting that began the plant) messes around with species cold hardiness, so if the red maple came from a seed source in northern Alabama (part of its native range), it is likely to be less cold hardy than seed from a red maple growing in Winnipeg (part of its native range). It’s hard to see provenance, so you need to find a reputable supplier of nursery stock that is from seed (or any propagule) sources native to your range. It gets more complicated. Stresses from exposure to sodium and chlorine ions (deicing salts), impacts cold hardiness…and not in a good way. So does any other stress: early defoliation (like from gypsy moths), construction damage to root systems, seasonal drought, over-pruning, and pH extremes. So, cold hardiness is a lot more difficult than opening up some book and reading the assigned hardiness zone.

Do Something About It!

Although not all winter damage can be predicted or avoided, there are some precautions that may be taken to minimize the damage. Most winter damage is the result of a combination of stressful events. Do your best to predict the type/s of winter damage and then focus your efforts on those avoidance techniques. Mechanical damage. Try the following techniques: Stem Protection. To reduce damage from abrasive materials hitting the bark of young, thin barked trees, wrap the stems with crinkled kraft tree paper, plastic spirals, cardboard “sleeves” or tree shelters. Apply these in mid-late autumn and remove in early to mid-spring. To reduce animal damage on tree stems with thin and/or smooth bark, protect the stems with “hardware cloth” (1/4 to 3/8 inch openings). Apply this product as a protective cylinder around the stem and up to the first branches or at least to the point where most of the animal damage is likely to occur. Make the cylinder large enough in diameter to leave at least one inch between the tree bark and the wire.

To prevent stems from splitting out from ice and heavy snow loading events, provide temporary support to the multiple leaders. This is usually a problem with multiple-stemmed evergreen trees and shrubs, most commonly northern white cedar, junipers and yews. Either interior or exterior temporary supports may be used. Interior support can be provided by “tying” the stems together. Materials such as ARBORTIE or tree chain (interlocking plastic chain) are good to use since they are simple to apply and may be re-used. Stem and Foliage Protection. Exterior support can be provided by binding the branches/stems together from the outside of the branches. ARBORTIE, burlap wrapping, green jute rope, or just about anything that is strong enough to hold the branches together may be used. Begin wrapping the supportive material from the bottom of the tree or shrub. Secure the material around the stem at the ground line, and then gently hold the branches in place while you wrap the material around the plant…tight enough to provide support, but loose enough to avoid breaking branches or ruining the form of the plant. Bud capping can be used where the animal damage is to the uppermost, growing shoots of conifers. This technique is very simple and very effective. Simply fold an index card in half, put it over the top shoot of the evergreen tree and staple the ends together so that it stays over that top shoot. Desiccation of the Foliage. Desiccation will result from above ground exposure and below ground water supply. Above Ground Exposure. About the only things that can reduce this type of damage involve either building a screen to slow down the drying winter winds or deicing salt spray drift, or wrapping the plants’ foliage to minimize exposure. Screens may be made with snow fences or some of the “plastic” fences now available. Drive two stakes in a line perpendicular to the prevailing winds on the windward side of the plants and stretch the screening material from one stake to the next. If the screen is placed a few feet away from the plant, closer to the offending exposure, it Will the Pines... continued on p. 16

Winter 2006• ADVOCATE

STAC INFO & NEWS

About MnSTAC The Minnesota Shade Tree Advisory Committee (MnSTAC) was established in 1974 by a group of concerned citizens to address the health and well being of community forests. MnSTAC is recognized throughout Minnesota and the country for its expertise, advice, coordination and support for community trees. It is an organization of diverse individuals who represent a broad spectrum of tree-related interests. It fosters and supports local community tree programs across the state so healthy community forests are fully integrated into community development, infrastructure, education and management. MnSTAC Board of Directors President: Ken Simons—763/717-9366 Vice President: Michael Max, EnvironMentor Systems, Inc. —763/753-5505 Valerie Cervenka, Minnesota Department of Agriculture— 651/296-0591 Jim Hermann, Mpls Park & Rec Board/Forestry—612/370-4900 Ken Holman, DNR/Forestry—651/259-5269 Steve Nicholson, Kunde Company—651/484-0114 Gary R. Johnson, U of M/Forest Resources—612/625-3765 Robert Slater, MN Dept. of Transportation —507/529-6145 Kirk Brown, Tree Trust—651/644-5800

Regional MnSTAC Committees Southeast STAC

Chair: Henry Sorensen—651/388-3625 or 651/385-3674 Sec./Treas.: Katie Himanga, Heartwood Forestry, Lake City —651/380-9680

Northeast STAC

Chair: Kelly Morris, City Forester, City of Grand Rapids —218/326-7481 Secretary/Treasurer/Technical Advisor: Dan Jordan, IRRRA Mineland Reclamation—218/254-7967

URBAN AND COMMUNITY FORESTRY

Calendar

Events

January 4-6, 2006, Minnesota Green Expo, Minneapolis, Minnesota www.minnesotagreenexpo.com

April 10-12, 2006, Trees and Utilities National Conference, Chicago, Illinois, www.arborday.org

January 10-12, 2006, Indiana Arborist Association Annual Conference, Indianapolis, Indiana, www.indiana-arborist.org

July 29-August 2, 2006, International Society of Arboriculture’s Annual Conference, Minneapolis, Minnesota, www.isa-arbor.com

February 1-3, 2006, Missouri Natural Resources Conference, Osage Beach, Missouri, www. mnrc.org February 12-17, 2006, Municipal Forester Institute, Lake Arrowhead Conference Center, California, www.urban-forestry. com February 17, 2006, Minnesota Society of Arboriculture Winter Conference, Rochester, Minnesota, www.isa-msa.org February 28-March 2, 2006, Minnesota Society of American Foresters Winter Meeting, Brainerd, Minnesota, www.mnsaf. org March 4-7, 2006, Conference on University Education in Natural Resources, East Lansing, Michigan, www.for.msu.edu/ UENR March 14-15, 2006, Iowa Shade Tree Short Course, Ames, Iowa, www.ucs.iastate.edu March 21-22, 2006, Minnesota Shade Tree Short Course, Bethel University, Arden Hills, Minnesota March 29-April 2, 2006, American Society for Environmental History/Forest History, Saint Paul, Minnesota. Contact Steve Anderson, email: stevena@duke. edu or phone: 919-682-9319

ADVOCATE • Winter 2006

April 8-12, 2006, The International Symposium on Hydrology and Measurement of Forested Wetlands, New Bern, North Carolina. Contact Sharon McKnight, email: mcknight@asae. org, phone: 269-428-6333

New Publications Cities in the Wilderness. Bruce Babbitt. 2005. Island Press Economics, Sustainability, and Natural Resources: Economics of Sustainable Forest Management. Shashi Kent and R. Albert Berry. 2005. Kluwer Academic Publishers

Websites Forestry Library (Online) http:// forestry.lib.umn.edu/agnic/ index.phtml Global Association of Online Foresters www.foresters.org Minnesota Climatology www.climate.umn.edu Minnesota Native Plant Society www.mnnps.org

Scholarships and Fellowships The Garden Club of America awards scholarships and fellowships to students and researchers in the fields of Urban Forestry, Landscape Architecture, Horticulture, Ecology, Botany, and Environmental Studies. For more information, visit their website at www. gcamerica.org/scholarships

For handy up-to-date links to web sites of interest, be sure to visit

www.mnstac.org 15

Minnesota Shade Tree Advocate A quarterly newsletter published by the Minnesota Shade Tree Advisory Committee. Managing Editorial Group: MnSTAC Education Committee (Emily Barbeau, James Burks, Ken Holman, Gary R. Johnson, Lara Newberger, Jeff Rick, Mark Stennes, and Patrick Weicherding) Editor-in-Chief: Judy Slater judyslater@earthlink.net Design: Creative Services Unit, MNDNR Material in this newsletter is not copyrighted. Reproduction for educational purposes is encouraged. Subscriptions are free. Articles, news items, photos and videos are welcome. This publication was produced with the support of the U.S.D.A. Forest Service, Northeastern Area; State and Private Forestry. Address inquiries to: Minnesota DNR Division of Forestry 500 Lafayette Road St. Paul, MN 55155 Printed on recycled paper using soy-based inks.

Will the Pines... from p. 14 won’t be necessary build a screen as tall as the plant. Winds will be deflected up when they hit the screen; often a four foot high fence will protect a 6-8 foot tall evergreen. Burlap, plastic fencing, bird or deer netting can be used to wrap and protect the foliage if you don’t use a screen. Below Ground Water Supply. Water the plants well into the autumn – water until the ground freezes. YOU WILL NOT FORCE PLANTS OUT OF DORMANCY BY WATERING THEM! (By midautumn, plants are well on their way to full dormancy.) If the landscape is poorly drained, don’t water to the point that the trees are flooded. Correct the drainage problem as soon as possible. Mulch as much of the root system as possible with 2-4 inches of wood chips or some other nice mulch. Don’t apply the mulch if the soil is dry. Make sure the soil is nice and moist before the mulch is laid on the surface. Mulch doesn’t make soil moisture…it conserves it. Antidesiccants are really novel ideas. So are time-machines.

Cold Temperature Damage.

To avoid or minimize cold temperature damage, keep the trees and shrubs healthy during the growing season. Don’t over prune, wound their stems, forget to water them, accidentally spray them with

Minnesota Shade Tree Advocate 500 Lafayette Road St. Paul, MN 55155-4044 RETURN SERVICE REQUESTED

herbicides, plant them in compacted and/or poorly drained soils, mess up the soil’s natural pH, or anything else that would unnecessarily stress the plants. Mulch the root system or as much of it as possible. It’s really amazing just how much mulch insulates and regulates soil temperatures. Just like in a forest! For landscape/patio trees or shrubs that are growing in pots or containers, if possible, bury the containers in the landscape during the winter and mulch over the root system.

Where to find materials.

1. Garden centers and nurseries. Don’t ask for advice. Ask for the product. 2. Home improvement centers, neighborhood hardware stores, feed and grain stores. Don’t ask for advice. Ask for the product. Also, ask for any extra burlap that they may have and want to discard. 3. Fabric stores. Great places to buy bolts of burlap. 4. Mail order companies that specialize in gardening, forestry, nursery and landscape supplies. Don’t assume that these places will be less expensive than your local hardware store. Gary R. Johnson is a Professor of Urban and Community Forestry in the Department of Forest Resources, University of Minnesota.

Presorted Standard U.S. Postage PAID Permit No. 171 St. Paul, MN

Winter 2006 • ADVOCATE