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VOL. 6, NO. 4

Fall 2004


Citizen Forester Program Rochester, Minnesota By Jacob Ryg

he city of Rochester has a need for boulevard trees. With the onslaught of Dutch elm disease and the plague of stem girdling roots, Rochester’s city streets are looking bare. Fortunately, Rochester received a Minnesota Re-Leaf grant to address the need for a healthy, diverse, properly planted street tree population. With the assistance of the grant and other city entities, the citizen forester program was established. In these difficult times of budget cuts and hiring freezes, trees and green spaces seem to take the brunt of the cutbacks. Many small communities have been forced to leave diseased trees standing for years, until they can find budget dollars for tree removal. Planting trees is completely out of the question. Rochester needed a way to continue to replace many of the “high risk” boulevard trees in order to restore the once plentiful city tree cover that is being diminished each year. The intent of the citizen forester training is to give the average citizen a stake in their community’s “green utility”. Trees are an important part of a city’s living legacy. When cared for properly, trees can provide gratification to countless generations of city residents. Trees are the only thing that a city can routinely buy that increases in value over time. The public showed great interest in the Citizen Forester Program. We had people come from communities fifteen miles away, but the vast majority of the trainees were from Rochester. Their commitment included attending four mandatory training sessions. Many of the participants were drawn in by the promise of free trees to plant on their city boulevards. In honor of the City of Rochester’s 150th birthday, we decided to give away 150 trees that will be planted on a community-wide planting day. Citizen Forester Program continued on p. 3



Inside THIS ISSUE 2 Perspectives Column 4 Dispel-A-Myth: Giving the Gingko a Second Look 5 Urban Forest Health: Using Bio-stimulants in the Urban Landscape 8 Clip & Save: How to Kill a Tree - Herbicide Advice for Homeowners 12 MnSTAC Celebrates 30 Years 14 Landscaping With Native Trees 15 STAC Info and Calendar

Visit MnSTAC on the Web at

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 • Fall 2004



ETERNAL VIGILANCE: THE PRICE OF GOOD URBAN FORESTS by Donald C. Willeke Thomas Jefferson often quoted John Curran’s famous phrase, “Eternal vigilance is the price of liberty.” Eternal vigilance is also the price of good urban environments and their principal element: our urban forests. On this, the thirtieth anniversary of the founding of Minnesota’s urban forest council and the commencement of the battle against Dutch elm disease and oak wilt, it is sad to note, but clear that we are no longer as vigilant as we once were. Dutch elm disease is rising in a major way throughout many parts of Minnesota. Any knowledgeable observer over the past several years could have predicted that (and many of us did). For example, in the Seven County Metropolitan Area, the amount of dead and dying elms left standing for long periods has obviously increased significantly in the past five years. Many metropolitan municipalities have cut their tree budgets in an effort to save money, and have cut back on enforcement of removals. Minneapolis has reduced the frequency of its trimming of large elms. The Department of Transportation has done a poor job of removing dying elms along highway right of ways. Did any knowledgeable “tree person” think anything different than the present increased losses would result sooner or later? And have we been vigilant in using the present renewed crisis to educate as we once did? What handouts have been prepared for homeowners (and nailed to each condemned tree) telling where Dutch elm disease comes from, and why trees must be removed promptly and why elm wood must not be stored with the bark on? I’ve never even seen even one such “broadside” in any major city or suburb in recent years! We have very laxly ignored these “teachable moments”. In similar fashion, those of us who care for our urban forests have not continued our past vigilance in educating the public to care for its present stock of large trees (mainly big elms and oaks) and to take care of new trees. When was the last time anyone saw a “Water me every week!” tag on a newly planted municipal tree? What “new tree care” leaflets are given to homeowners when new trees are planted in neighborhoods? I have seen few or none. They should be used everywhere new public trees are planted. Even the care of new trees is obviously lax. For two years we have had summer droughts. But watering newly planted trees (and even those planted several years ago) seems to be an afterthought (at best) in our governmental planning? Vigilance? Hardly. It is my fear—and my conclusion—that far too many urban forestry officials have retreated into the same old “professional cocoons” in which they existed when we started to publicize the dangers of Dutch elm disease and oak wilt in 1974. They have forgotten that they have to be “politicians” for trees, and that they have to be walking “Extension Departments”—never missing an opportunity to educate the public, and never missing opportunities to get to the public through many types of media now available. Why this should be true is a mystery to me, because everyone knows that when we “shouted” we “succeeded.” I wish, on the thirtieth anniversary of our common Minnesota effort that succeeded very well for years, that I could be more up-beat, but I do not think any realistic appraisal of our urban forests in the Twin Cities and throughout Minnesota’s other communities permits it today. Our vigilance for our urban forests cannot be either low-key or intermittent. It must be eternal.

No shade tree? Blame not the sun but yourself. – CHINESE PROVERB

Donald C. Willeke is the former Chair of the National Urban Forest Council and the Minnesota Shade Tree Advisory Committee.


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Citizen Forester Program from p. 1 In session one of the mandatory training, we dove right into tree basics. We asked the most fundamental question every forester should ask: Why are trees important? We also studied local issues such as deforestation, stem girdling roots, and identifying high quality nursery stock. The most important part was teaching the citizens how much they can do to take care of trees. I also shared my goals for the city forestry program: plant more trees, maintain existing trees, tree protection and educating the public. Session two was devoted to discussing physical tree needs and features. Countless people still think that tree roots go straight down, or that it’s always right to plant the tree at the same depth as it was planted at the nursery. Our mantra became “plant trees at the correct depth” (With the trunk flare above ground)!! During the third session, our last indoor class, we taught specifics that included long-term plant health care and maintenance. We created and followed a stepby-step process of choosing the right tree for the right spot, including considerations such as species, form, and quality. I personally think it helped the trainees when we spoke in detail about how trees form their roots, how they utilize elements and why most trees have a majority of their root systems within the top eighteen to twenty inches of soil. This type of factual information helps dismiss many of the myths associated with trees. In our fourth and final session, we had a field day. Everyone was ready to get outside and see the things we had discussed in the classroom put into practical application. The city and its NeighborWoods partner purchased T-shirts and “Official Citizen Forester” certificates for each participant. During the field day, we planted a dozen trees in an older city park to commemorate the beginning of a new era of forestry in Rochester. Everyone got their hands dirty digging holes and finding the first lateral root (for correct planting depth). We provided a packet of materials, purchased from the International

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Society of Arboriculture, which had information about planting trees properly, buying high quality trees and proper mulching techniques. We even brought along some tree climbing equipment and convinced some brave people to climb a large Norway maple which was standing in the shadow of a 50-inch diameter Dutch elm diseased tree. It was great to talk about the impact of the huge tree losses we have each year and how much of these losses can be avoided through education, protection and having a basic understanding of how trees grow. Each new citizen forester has received a letter in the mail with a copy of their local (three block radius) tree inventory and empty planting space map. They have also received a list of tree species that they will be planting. All of the stock, which the city purchased with grant dollars, consists of bare root stock from cold hardy seed sources. The citizen foresters will contact each property owner that has open planting spaces to see if the owner wants a free tree planted on the boulevard. Each citizen forester is then required to obtain a utility locate and follow city planting guidelines to reduce infrastructure conflicts. PHOTO BY JACOB RYG Rochester’s community tree planting day is scheduled for October 23, 2004. Each citizen forester has the option of having me present for the tree plantings on a staggered schedule. They can also choose to have free woodchips, donated by the city, dropped off at their home for distribution to each new tree owner. Implementing a citizen forester training program provides a great way to get additional support within the community. How many people do you have in your community who want to actively do something with trees? It is nice to know that we have a great group of people in the Rochester area who are willing to give something back to their community’s urban forest. I encourage other municipalities to get their citizens involved in tree planting and taking pride in their community tree heritage. Jacob Ryg is the Forestry Supervisor for the City of Rochester, Minnesota.



GIVING THE GINKGO A SECOND LOOK New Cultivars Make This Awesome Urban Tree Even Better

By Eric Mader


For More Information Boyd Nursery homepage. 2003. http://www. Cochran, K. 1998. Ohio State University Cooperative Extension Service homepage. The Marketing Potential of Ginkgo biloba in the United States. http://ohioline. 13.html Kwant, C. 2000. The Ginkgo Pages Website. http://www. Major, R.T. 1967. The Ginkgo, the Most Ancient Living Tree. Science. Vol. 157, No. 3794: 1270-1273. Michigan State University Extension Website. 1999. Ginkgo biloba—The Maidenhair Tree. http://www.msue. modzz/00000667.html Ohio State University Extension website. 2004. Ginkgo biloba. Plantlist/gi_iloba. html

h no. Not another stinkgo! Don’t With striped leaves, and horizontal or unusual you know those things have terrible growth habits, these are not your typical boulevard smelling berries?” When city foresters plant a ginkgoes. ginkgo these days that is the reaction they often Among the most exciting of these new get. cultivars are ‘Rainbow, ‘Streamside’ and Unfortunately ‘Variegata,’ three many people mistakenly Table 1. Common Ginkgo Cultivars. selections with striped assume that all ginkgoes or variegated foliage. produce foul smelling Both Rainbow and NAME COMMENTS fleshy seeds, but in Streamside are striped fact only the female with yellow bands, Autumn Gold Deeper golden-yellow fall trees do. Unscrupulous while Variegata is a color, with broad pyramidal or inattentive nursery true green and white growth habit at maturity. owners occasionally sell variegated variety. Chase Manhattan Compact with tiny dark leaves. female trees, and new Some people have Fairmount Tall, spindly form. research indicates that in reported problems with rare instances ginkgoes individual branches Fastigia Extremely tall, narrow. may actually switch on Variegata reverting Globus Column shaped with very large genders! Despite the back to all green leaves leaves. occasionally annoying so regular monitoring Horizontalis Spreading, less upright form. smell, ginkgo seeds and occasional pruning provide food for wildlife, is required with this Jade Butterfly Dense, dark foliage in clumps, and are prized as a shrubby appearance, semivariety. dwarf. food source in Asia. In Additional addition, recent medical foliage variations Lacinata Fringed and deeply divided research has identified a are available with leaves. series of chemicals called ‘Tubifolia, ‘Laciniata,’ Lakeview Compact, broad pyramid ginkgolic acids which and ‘Saratoga.’ shape. may have potential for Tubifolia is the most Mayfield Extremely tall, narrow. new cancer treatments. striking of these Weeping form. With all of these benefits, Pendula cultivars with distinctly the occasional weird tubular leaves, curled Princeton Sentry Nearly columnar form, being smell really is pretty to resemble small slightly wider at the base. inconsequential. funnels. Lanciniata Prague Low, spreading, umbrellaThe other objection features deeply divided shaped. people often have to leaves with a fringed Rainbow Striped yellow/green leaves. the ginkgo is the gangly appearance, and appearance of young Saratoga Narrower leaves. Saratoga produces trees. Young ginkgoes narrower, more Spring Grove Very dwarfed, less than 3 do have a spindly triangular leaves than meters tall. appearance, but mature other cultivars. Streamside Yellow and green variegated trees normally have a Other cultivars leaves with little tendency broad vase-shaped form are variations on towards reversion. similar to the American the ginkgo’s normal Tremonia Extreme columnar form like elm. shape and growth Lombardi poplar. While some people habit. ‘Pendula’ is a Tubifolia Tubular curled leaves. would like to see the weeping variety that ginkgo gone, new resembles a willow. Variegata Variegated leaves. cultivars are causing ‘Horizontalis’ is a Witch’s Broom Irregular, deeply lobed leaves. other people to give the massive spreading tree ginkgo a second look. with extremely long


Fall 2004 • ADVOCATE

horizontal branches. ‘Fastigia’ and ‘Mayfield’ are both extremely tall, columnar trees that resemble certain conifers in the landscape. Additional cultivars are described in Table 1 (see page 4). The fact that the ginkgo can tolerate poor conditions like soil compaction, high soil pH, heat, drought, salt, and air pollution, makes it the ideal urban tree. Even more impressive, a mature ginkgo can live for thousands of years, and has virtually no insect or disease problems. In municipal settings, city foresters already know the ginkgo is unmatched as a boulevard tree. In the home landscape, creative gardeners will discover the ginkgo is easily trained into a variety of forms, from espaliers and hedges, to climbing shrubs which resemble vines. With all these options, the ginkgo is not simply another urban tree—it is a conversation piece.


Eric Mader is a Student at the University of Minnesota.


Using Bio-stimulants in the Urban Landscape By Cindy Buschena

If you think all that’s needed to grow a tree in the urban landscape is soil, sun, water, and maybe some fertilizer, think again! Most, if not all, urban landscapes are quite different from a tree’s natural habitat - making it a challenge to grow healthy, vigorous trees. Urban soils have been disturbed by cuts and fills, are compacted, have abrupt or no soil horizons, and possible contamination from pesticide residues or heavy metals. These unnatural conditions result in interrupted soil biological cycles and low organic matter–making urban soil a poor habitat for trees. If a soil is not “healthy”, can adding missing components make it healthy? First, how do the biological and organic components of healthy soil work?

Humus, Humate, Humic acid

Humus makes up the largest component of the bio/organic soil and is the result of decomposition of dead organisms. Both ‘humate’ and ‘humic’ refer to soil organic compounds. The humic layer is the rich, brown to black layer usually found in the uppermost part of a natural soil profile. Humate and humic acid have generally the same chemical properties, as humates are mineral salts of humic or fulvic acids. Humic acid can be extracted from any material containing well decomposed organic matter, thus

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humic substances differ depending on their origin. Because humic acid is a result of the biological decay of organic matter, it is resistant to further decomposition. Humus helps improve soil structure, increases soil water holding capacity, and improves the solubility of some soil nutrients. Some other benefits of humic acids, as extolled in the promotion of commercial biostimulants, are not well documented, therefore uncertain.

Bacteria and Fungi

Even though they make up a small percentage of the soil ecosystem, living soil organisms carry out numerous beneficial functions. They help in the decomposition of organic matter, formation of soil humus, improve some soil properties, and suppress some plant pathogens. The rhizosphere, the thin layer of soil area around roots, can contain 100-200 billion microbes! Imbalances in the soil microbial community can result in disease and reduced growth. Soil fungi include symbionts (mycorrhizal fungi), saprophytes, and pathogens. Since fungi don’t possess chlorophyll, they must absorb their carbon from dead or living organic matter, and thus serve as organic matter decomposers. The benefits of mycorrhizal fungi on tree establishment are well documented. Using Bio-stimulants continued on p. 6



Using Bio-stimulants from p. 5 Bacteria are present in vast quantities in the soil and serve many important roles. Various bacteria metabolize phosphorus and iron bonds, create soil carbon, and mineralize nutrients. Some bacteria produce antibiotic substances (streptomycin, terramycin, bacitracin, penicillin, etc.) which inhibit or kill other soil organisms. Other bacteria are responsible for nitrogen fixation - the process of chemically altering free atmospheric nitrogen into a form usable by trees. Some microbes also produce hormones which benefit plants. Humus and living soil microorganisms can be considered biostimulants because they directly or indirectly enhance or stimulate biological processes. However, the term “bio-stimulant” is also a very broad and vague term used to describe certain products applied as soil amendments or sprayed on foliage to enhance plant growth or reduce transplant shock. The term biostimulant has been used to include a large category of materials, resulting in confusion and often false claims. People have used biostimulants for centuries, by incorporating animal and plant material into soil around their crops. No one doubts that soil organic matter is important, though organic matter found in manure and other decayed materials do not directly benefit plants. Rather, organic materials help improve some physical soil properties, and, in the process of decomposition, some nutrients become available to plants. In addition to humic substances and living soil organisms, commercial biostimulant products can include nutrients such as Mg, Fe, B, Cu, Mn, Zn, Mo, S and N; organic substances such as plant extracts, kelp, marine algae, and fermented milk culture; vitamin B complex; amino acids; and enzymes. Commercial biostimulants are touted as having the ability to increase shoot and root development, improve soil texture and soil structure, increase availability of soil nutrients, improve a tree’s ability to bounce back after disease and insect damage, reduce the adverse impact of environmental stresses, reduce transplant shock, improve fertilizer performance, and reduce adverse affects of pH or other soil imbalances. Truly amazing stuff!!!

Why Sea Kelp?!

Nutrient additions have obvious benefits for tree growth. Bacteria and/or fungi are added in case the soil is deficient in them. Plant extracts (simple sugars, protein, and carbohydrates) are


included in biostimulant products as a food source for bacteria in the product until the bacteria become established in the soil. Seaweed or kelp extracts are included in some biostimulant products as a source of plant growth hormones, manitols, and trace elements. These compounds could promote cell division and elongation in tree roots. However, amounts of plant hormones contained in seaweed extracts are small and even if there were hormonal effects, they would be negligible. Is there evidence that addition of biostimulants, in the form of commercial products, can restore the properties of healthy soil and thereby improve tree health? Refereed literature on commercial biostimulant products is limited and without consensus.


Several types of biostimulants were tested on red maple and Washington hawthorn, both with and without irrigation and fertilization. Soil treatments, applied at planting, were: 1) control, 2) compost, 3) sphagnum peat, 4) 100 g/tree granular humate, 5) 200 g/tree granulate humate, and 6) liquid humate + a mixture of humate, kelp extract, thiamine, and intermediate “metabolites.” Soil treatments did not increase height, stem diameter, top dry mass, or root length in red maple. For Washington hawthorn, the results were similar for tree height, stem diameter, and root length, but compared to controls all treatments increased above ground biomass. In particular, the humatetreatment showed a strong effect on tree biomass. In addition, roots of peat treated trees had longer roots than those in other treatments. In hawthorn, but not red maple, granular humate at 200 g/tree increased total root length more than at 100 g/ tree. Nitrogen fertilization at time of planting had no effect on either species. In these experiments, biostimulants resulted in limited improvement on early post-transplant growth. In another study, four major humate-based biostimulants were found to have no effect on root or shoot growth of container grown plants. Products tested were manufactured by Earthgreen Products, GrowplexTM, and RootsTM. Soaking the roots in a humate-based biostimulant actually reduced plant growth. Following transplanting, four biostimulants (trade names ‘Generate’, ‘Crop Set’, ‘Fulcrum’, ‘Redicrop 2000’) were applied as a root drench or foliar spray on three transplant sensitive species, red oak (Quercus rubra), birch (Betula pendula) and beech (Fagus sylvatica) in the UK. Effects were measured at 8 and 20 weeks after application. Generate and Fulcrum increased growth of all three tree species. Applications of Crop Set and Redicrop 2000 significantly Fall 2004 • ADVOCATE

increased growth in red oak growth, but not birch or beech. Generate increased chlorophyll fluorescence in all three species. These results suggest that application of biostimulants following transplanting may be beneficial, but not in all tree species. In another study, biostimulant products were applied to balled and burlapped red maple to test root growth and sapflow. Treatments included: 1) wettable powder of humate applied as a soil drench; 2) liquid formulation of humate with various putative root growth-promoting additives applied as a soil drench; 3) dry granular humate applied as a topdress; and 4) control. Treated trees had no greater root length than controls, and soil drench treatments had the lowest root length throughout the 20 weeks of study. All treatments increased sapflow.

The Bottom Line

Application of some soil amendments (such as peat) and biostimulants (such as granular humate) may increase root growth after transplanting for some species. Some biostimulants have been shown to increase sap flow after transplanting, indicating that some trees might benefit from treatment. However, long-term benefits, and effectiveness under conditions of extreme drought, urban soils, and flooded soils are unknown.

Unfortunately, no equivalent of the Food and Drug Administration exists for biostimulant products. The industry is unregulated and not subject to quality control testing. If the active ingredients of biostimulants are living organisms and organic chemicals, they have a limited shelflife and old products may loose any potential effects. Many complex and interrelated variables operate in soil ecosystems, so no ‘magic potion’ will restore the functions of healthy soil. As a rule, if a product sounds too good to be true, it probably is! Commercial biostimulant products will not correct problems caused by improper planting or poor site or poor species selection. Moreover, biostimulants can not be considered as replacements for lack of soil fertility, water holding capacity or drainage. They are not the solution for compacted and otherwise damaged soil, nor will they compensate for poor cultural practices. The benefits of humus and balanced populations of microbes can be found in good compost. Good compost may also be a more affordable alternative to many biostimulant products. The rationale behind the inclusion of various ingredients in biostimulant cocktails seems reasonable, yet, to date, there is little evidence proving that positive effects will result from their use. REFERENCES: Ferrini. F. and Nicese, F.P. 2002. Response of English oak (Quercus rober L.) trees to biostimulants application in the urban environment. J Arboriculture 28(2):70-74. Fraser, G.A. and G.C. Percival. The influence of biostimulants of growth and vitality of three urban tree species following transplanting. Arboricultural Journal Kelting, M.P., J.R. Harris, J.K. Fanelli, A.X. Niemiera, and B.L. Appleton. 1997. Humate-based biostimulants do not consistently increase growth of Turkish hazelnut. J. Environ. Hort. 15:197-199. Kelting, M.P. 1997. Effects of soil amendments and biostimulants on the post-transplant growth of landscape trees. M.S. Thesis Virginia Polytechnic Institute and State University, Blacksburg, VA. Kelting, M.P., J.R. Harris, J.K. Fanelli, and B.L. Appleton. 1998. Humate-based biostimulants affect early post-transplant root growth and sapflow of red maple. HortScience 33:342-344. Kelting, M.P., J.R. Harris, J.K. Fanelli, and B.L. Appleton. 1998. Biostimulants and soil amendments affect two-year post-transplant growth of red maple and Washington hawthorn. HortScience 33:819-822 Cindy Buschena is a Scientist at the University of Minnesota, Department of Forest Resources.

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“How to Kill a Tree” -

Herbicide Advice for Homeowners By Patrick Weicherding


Herbicide Advice for Homeowners 8

oody plants that are “undesirable” in natural areas of public lands also occur on private property. These may have been planted intentionally or introduced as seeds from other areas by birds and wildlife or they may have spread vegetatively across property lines. Some of these plants are described as being “invasive” and when they are growing on private property can serve as a source of infestation to nearby natural areas. Generally, homeowners are encouraged to remove invasive plant species (local ordinances sometimes require their removal) but sometimes they simply want to get rid of trees or shrubs that have outgrown their usefulness. Control methods that can be used by homeowners are similar to those used in natural resource management by professional land managers. However, the scale of the control effort can be very different, ranging from the removal of a single tree to removal of several acres of woody species. Homeowners with several acres of undesirable plants, especially invasive plants, may use similar methods and herbicides as professional land managers, while those with small areas or a small number of trees can use simpler methods. The principle difference in herbicides used by professional land managers is packaging, where products can be purchased in concentrated form in large quantities. Usually, a pesticide applicator’s license is required to purchase and use these products. This article discusses methods and herbicides that can be readily used by homeowners for removal of undesirable species, and is intended for general information only. Directions for use on the manufacturer’s label of specific herbicides must be

followed. Also note that many cities and counties have tree preservation ordinances that prohibit the random destruction of trees and shrubs. Always check with your local government officials to determine if a permit or permission is required before removing unwanted trees.


Herbicide products can be purchased in many different forms depending for the most part on how they will be applied. Generally, they contain an active ingredient, a diluent (to dilute the product), and sometimes other additives that enhance the performance of the herbicide (such as surfactants). The active ingredient may be either oil soluble (diluted in oil) or water soluble (diluted in water). Active ingredients contained in the majority of herbicide products used by professional land managers are triclopyr amine (water soluble), triclopyr ester (oil soluble), glyphosate (water soluble), and imazapyr (water and oil soluble) (see Table 1). Herbicide products that contain imazapyr are not recommended for use in home landscapes because of the potential for imazapyr to be taken up by the roots of desirable plants that could be injured or killed.

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Table 1. Herbicides used for control of undesirable plant species ACTIVE INGREDIENT



Glyphosate 3 lb/gal

Roundup Pro, Glyphos, Glypro Plus, Touchdown Pro

Farm supply stores. Containers 2½ gallons and up.

Glyphosate 3.7 lb/gal

Roundup Super Concentrate

Retail garden supply stores. Containers as small as 1 quart.

Triclopyr amine 3 lb/gal

Garlon 3A

Farm supply stores. Containers 2½ gallons and up.

Triclopyr amine 0.59 lb/gal

Brush Killer

Retail garden supply stores. Containers as small as 1 quart.

Triclopyr amine 0.54 lb/gal


Retail garden supply stores. Containers as small as 1 quart.

Triclopyr ester 4 lb/gal

Garlon 4

Farm supply stores. Containers 2½ gallons and up.

Triclopyr ester 0.75 lb/gal

Pathfinder II

Farm supply stores. Containers 2½ gallons and up.

Triclopyr ester 0.75 lb/gal


Internet. Pint and 12 ounce containers.

Note: Active ingredient is reported as acid equivalent.

Triclopyr amine – Commonly used herbicide products that contain triclopyr amine are Garlon 3A, BrushB-Gon, and Brush Killer (Table 1). Garlon 3A is a concentrated product (3 lb triclopyr per gal), packaged only in large volume (2.5 gal or larger), and available only at farm supply stores. Brush-B-Gon and Brush Killer are more dilute than Garlon 3A, are packaged in small containers (quart containers), and can be purchased at retail garden supply centers. They are readily available and convenient for the small property owner to use. Triclopyr ester – Commonly used herbicide products that contain triclopyr ester are Garlon 4 and Pathfinder II. Garlon 4 is a concentrated product that is diluted in water or oil before use. Pathfinder II is pre-diluted in oil and ready to use. Both Garlon 4 and Pathfinder II are packaged in no smaller than 2.5 gal containers and available from farm supply stores. Vine-X is a new product that contains triclopyr ester ready-mixed in oil and sold in small applicator containers. It can be ordered on the Internet at Glyphosate – Roundup Super Concentrate is similar to the glyphosate-containing products used by professional land managers. Roundup Super Concentrate can be purchased in small containers from retail garden supply stores. Products that are more dilute than Roundup Super Concentrate also are available (not discussed in this article).

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Methods for Removing Undesirable Plants

HAND-PULLING – Newly emerged seedlings of woody plants, such as ash, elm and maple, frequently appear in home landscapes. Homeowners should be vigilant for these; when discovered early enough, they can be removed by hand pulling. The use of a foliar applied herbicide can make the job easier for large numbers of plants. Small trees in the landscape can be removed with the aid of hand pulling tools like the Weed Wrench™ or the Root Talon. The Weed Wrench™ is a manually operated, all-steel tool designed to remove woody plants by uprooting. The wrench has a vertical handle that is used to gain leverage. The base plate is placed on the ground next to the target plant to act as a fulcrum point. Two short arms with opposed gripping jaws are placed around the stem of the plant to be uprooted. As the woody plant is placed inside the jaws, the operator pulls down on the handle, and the jaws close on the stem. The leverage generated by the wrench pulls the plant and the roots system out of the ground. Mechanical specifications and prices for the various models can be found on the company’s website at The Root Talon is an inexpensive, lightweight alternative to the Weed Wrench™. It is a tool shaped like a pick-axe, but with a specialized fork and gripping flange that will let you grab onto a plant and pull it out of the ground. The Root Talon does not give you the pulling strength of a Weed Wrench™ but its weight and price makes it pretty attractive. Detailed information is available from the manufacturer, Lampe Design, LLC in St. Paul, MN. Phone: (651) 699-4963. STUMP GRINDING – When trees are cut down, the stumps are often ground out below the soil surface with a stump-grinding machine. This serves to remove the stump from view but adds additional costs to the tree removal. Costs for stump grinding are based on size and location of the stump to be removed. Information on sprouting of various tree species following stump grinding is not available but some species may re-grow from the stump or remaining roots. If root sprouts occur, they can be controlled using one of the herbicide application methods listed below. FOLIAR HERBICIDE APPLICATION – Foliar application refers to applying herbicide to the leaves (foliage) of unwanted plants. Seedling trees and shrubs can be controlled in this way with Brush-B-Gon, Brush Killer, or Roundup Super Concentrate. All are diluted in water before application. The herbicide solution should be applied so that it contacts


only the unwanted plant because it will kill most plants that it comes in contact with. CUT STUMP HERBICIDE APPLICATION – Stumps of some undesirable plants will resprout after cutting if not treated with a herbicide. Resprouts can be continually cut off as they appear, but applying herbicide to the stump will kill it and prevent resprouting. Stumps should be cut as close to the ground and as level as possible so that applied herbicide does not run off onto the ground. On large stumps, the herbicide should be concentrated just inside the bark. This is where the living tissue of the trunk is that will carry herbicide into the roots. Products that contain triclopyr amine, triclopyr ester, or glyphosate are effective for controlling regrowth of stumps of many undesirable species. Homeowners with only one or a few stumps to treat can use Brush-B-Gon, Brush Killer, or Roundup Super Concentrate. All three products can be applied undiluted. The stump should be free of sawdust and the herbicide applied as quickly as possible after cutting. BASAL BARK HERBICIDE APPLICATION – Woody plants can be killed without cutting the tree down by applying oil soluble herbicide to the bark of the stem. This is only recommended for trees or shrubs with stem diameters of six inches or less. This method is faster than cutting vegetation down and treating the stumps. It is useful for homeowners with larger numbers of woody plants to kill where it is acceptable to leave dying and dead vegetation standing. An oil soluble herbicide must be used for basal bark application to facilitate movement of the herbicide through waxy substances in the bark. Garlon 4 must be diluted in a penetrating oil that can be recommended where the herbicide is purchased. Pathfinder II is pre-diluted in oil and ready to use. Vine-X can be used for application to small stems (up to ¾ inch in diameter).

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FRILL OR GIRDLE HERBICIDE APPLICATION – Basal bark application will not be effective on trees with bark that is too thick for herbicide to penetrate. In this case, some bark must be removed before application of herbicide. A sharp implement such as a machete or hatchet is used to make cuts through the bark and herbicide is applied into these cuts. Cuts 3 to 4 inches apart (frill) are sufficient for some species, while a continuous cut completely around the trunk (girdle) is necessary for hard to control species such as cottonwood. Either water soluble or oil soluble herbicide may be used.

Herbicide Use and Safety

Anyone who applies pesticides on lawns and ornamentals as a business, or anyone who applies pesticides to their own business property or employees who apply pesticides to their employer’s business property, or any government employee who applies pesticides to lawns and ornamental plants, must be licensed according to the provisions of Minnesota state law. Additional information on pesticide licensing can be obtained at the University of Minnesota Extension Service, Pesticide Safety and Environmental Education web site at A license is not required to purchase or apply on your own (non-business) property any of the herbicides discussed in this article. A yard maintenance person who applies a pesticide to the lawn or ornamental plants of an individual residential property is exempted from licensing and certification requirements if the pesticides are owned and supplied by the individual property owner. Unlicensed yard maintenance people cannot advertise for, or solicit, pest control business and cannot represent themselves to the public as being engaged in pest control. Unlicensed yard maintenance people cannot supply their own pesticide application equipment, use pesticide application power equipment or use any equipment other than a handheld container when applying pesticides.

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It is essential and required by law for anyone using a herbicide (or any pesticide) to follow the “Directions for Use” on the manufacturer’s label. Training and information on pesticide use and safety is recommended for anyone who applies their own pesticides and is provided by the University of Minnesota Extension Service. Check out the web site at Patrick Weicherding is a Regional Extension Educator with the University of Minnesota Extension Service.

ADDITIONAL REFERENCES Hartzler, Robert G. 1999. Chemical Control of Unwanted Woody Vegetation. Iowa State University Extension, Forestry Extension Notes F-341. Heiligmann, Randall B. 1997. Controlling Undesirable Trees, Shrubs, and Vines in Your Woodland. The Ohio State University Extension, Factsheet F-45-97. Howard, Scott W. and Robert Parker. 1995. Chemical Control for Woody Plants, Stumps and Trees. Washington State University Extension, Extension Bulletin EB1551. McNabb, Ken. 2004. Environmental Safety of Forestry Herbicides. University of Alabama Cooperative Extension System, Publication ANR846. Motooka, Philip, Guy Nagai, Lincoln Ching, John Powley, Glenn Teves, and Alton Arakaki. 1999. Woody Plant Control for the Home, Pasture, and Forest. University of Hawaii Cooperative Extension Service, CTAHR Publication WC-4.


Minnesota Shade Tree Advisory Committee Celebrates 30 Years Congratulations to the following 30 people who were honored on MnSTAC’s Birthday for the talents, passion, time and energy they have generously given to MnSTAC over the years. Wendell Anderson John Bernhagen Lisa Burban Dr. David French Katie Himanga Dorothy Johnson Steven J. Kunde Mark C. Schnobrich Mark Stennes Dr. Katharine D. Widin

Peter Bedker Peggy Booth Lloyd Burkholder Peter Grills Ken Holman Gary Johnson Michael Max Glen Shirley Lorrie Stromme Donald C. Willeke

Tom Berg Kirk M. Brown David DeVoto Jim Hermann Skip Humphrey Hon. Henry Kalis Janette Monear Ken Simons Rolf G. Svendsen Michael Zins

Lara Newberger:

I went to my first MnSTAC meeting 12 years ago when I was an intern for the DNR. It was an excellent opportunity to meet people who care about community forestry. Now that I work as a community forester, I still attend MnSTAC meetings. It is a great way to get current forestry information from government agencies and to find out what is happening with the issues at the legislature that may impact community forestry. As the chair of MnSTAC’s awards committee, I have the opportunity to work with some great people within MnSTAC. Perhaps, best of all, I have had the honor of meeting truly dedicated people who have put in many, many hours of their “free time” to improve our world with trees.

Kelly Morris:

For those who may not recognize my name, please allow me to introduce myself. I am Kelly Morris, MnSTAC’s Chair of the Northeast Region. I am honored to be serving in this capacity. Because of my love for the tree, I have continued in education, and became a Certified Arborist for the Northern Minnesota area. Because we have such an abundance of trees in Northern Minnesota, it is becoming second nature to remove a tree without realizing its value. I work to educate my community on the value of keeping existing trees. So often we forget how many years it takes for the oak to mature. So many trees are cleared for construction purposes without realizing the value that trees add to property. When removal is necessary, it is important to plant a variety of different trees so that if disease is introduced, not all trees are lost. Trees are incredibly important for the beautification of Minnesota, so plant a tree or two or three.......


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Jacob Ryg:

As a new member of Minnesota’s Arboricultural community, I am excited about getting involved with MnSTAC. I’ve been on the job for less than a year as the forestry supervisor for the city of Rochester. Previously, I worked in Wisconsin, and being involved in Wisconsin’s arboriculture community was a wonderful experience. I hope that I can bring a fresh outlook to MnSTAC on the rapidly changing field of arboriculture. I think MnSTAC is a great advocate for Minnesota’s tree issues. I look forward to many years of involvement and effort to help drive Minnesota to the forefront of city tree preservation, care and reforestation.

Glen Shirley, a charter member of MnSTAC, shares some remembrances: The eloquence and concern of Don Willeke as he energized the group into the Minnesota Shade Tree Advisory Committee.

The “Minnesota Miracle” of millions of dollars for DED and OW management. Legislative funding - the Bernhagen report - on the conditions of Minnesota’s urban/community forests. The awe of being a young forester and working with the giants - DeVoto, Burkholder, French, Neetzel - to tackle the Dutch Elm Disease problem. Hosting the 1993 National Urban Forestry Conference. MnSTAC as the oldest statewide group in the nation supporting urban/community forestry. A great group of dedicated individuals.

ADVOCATE • Fall 2004


Landscaping With Native Trees

By University of Minnesota Extension Service


innesota has many native trees that can be used for landscaping. While commercial production is limited for many native species, each year nurseries produce more of these plants for sale. Many trees, however, are available only in the wild and must be moved from their native habitats if they are to be planted in the landscape. Legally, plants can only be transplanted from the wild when dug from private land or with permission. Even though they are native to this area, these trees require careful site selection. You must duplicate their natural growing environments as closely as possible if they are to thrive in the home landscape. Native plants are usually dug from the wild without soil on their roots. They should be transplanted in early spring before growth starts. This means they need to be identified in a dormant condition. If you can identify the plants only when they have leaves or flowers, mark them during the growing season, then move them the following spring. It is usually better to move small plants, because even with careful digging, only a small percentage of their roots will remain. Trees that develop a tap root, such as oaks and nut trees, are particularly difficult to transplant and should only be moved as very young plants. Nursery-grown plants typically have better root systems than those dug from the wild. This accounts for the higher percentage of nursery-grown plants that survive transplanting and become reestablished more quickly. Many years ago, it was believed that when woody plants were transplanted, they needed to be pruned above-ground to compensate for roots lost below ground. Do not thin out

branches or leaves to help the tree recover from transplant shock! Experimental research has subsequently dispelled that as a myth – those leaves produce energy for the tree that will help it become established in its new location – but there still may be some pruning required during the transplanting and recovery stages. Prune any broken, diseased, dead branches, and branches that are weakly attached (including bark at the branch attachment). After a year of “transplant recovery”, remove any dead branches that have likely developed and remove any multiple leaders. Young trees should only have one leader, so if there are two or more leaders fighting for control, leave the best one and remove the rest. Planting seed is another method of obtaining hard-to-find native plants. However, woody plants are more difficult to start from seed than most herbaceous plants. Some seeds may be viable for only a short time; some might require two or more years to germinate. Oak and nut tree seeds will not germinate if they are dried prior to planting. Most woody plant seeds require a period of cold and moisture, called stratification, before they can germinate. You can stratify the seeds indoors by placing them in moist sand at 32 to 40 degrees F for three or four months prior to planting. Planting stratified seed directly outdoors in spring is generally more satisfactory than attempting to start them indoors. You can also plant tree seeds outdoors in fall so they are stratified “naturally” over the winter. You must protect the seed bed from rodents by covering the area with mesh hardware cloth. Remember to remove the mesh in the spring before seedlings emerge.

They should be transplanted in early spring before growth starts. This means they need to be identified in a dormant condition. If you can identify the plants only when they have leaves or flowers, mark them during the growing season, then move them the following spring.

Landscaping with Native Trees continued on p. 16


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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 Kimberly Thielen-Cremers, Minnesota Department of Agriculture— 651/296-6692 Jim Hermann, Mpls Park & Rec Board/Forestry—612/370-4900 Ken Holman, DNR/Forestry—651/296-9110 Fletcher Johnson, Xcel Energy—651/639-4590 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 —651/345-4976

Headwaters-Agassiz STAC (HASTAC) Chair: John Johnson, City Forester, City of Thief River Falls—218/681-1835 Sec./Treas.: Jeff Edmonds, DNR Forestry, Bemidji —218/755-2891

West Central STAC

Chair: Bob Fogel, Director of Parks, City of Moorhead —218/299-5340 Sec./Treas.: Dave Johnson, DNR Forestry, Detroit Lakes —218/847-1596

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





November 8-11, 2004 The 2004 Annual Gypsy Moth Review, Indianapolis, Indiana. Contact Phil Marshall,

Great River Greening

November 9, 2004 Turf and Ornamentals Workshop, Andover, Minnesota. Contact Ruth Martin, 612-624-3492 or

Lake States Forest Health Watch Newsletter newsletters/lsfhw/index.html

January 5-7, 2005, Minnesota Green Expo, Minneapolis Convention Center www.minnesotagreen February 18, 2005, Rochester Urban Forestry Workshop, Rochester, Minnesota Contact Jay Maier 507-286-8733 March 23-24, 2005 Minnesota Shade Tree Short Course, Saint Paul, Minnesota

New Publications Emulating Natural Forest Landscape Disturbances: Concepts and Applications. Ajith H. Perera, Lisa J. Buse, and Michael G. Weber. 2004. Columbia University Press. Molecular Genetics and Breeding of Forest Trees. Sandeep Kumar and Matthias Fladung. 2004. Haworth Press.

Heat Island Effect

Minnesota’s Woody Plants treekey/navikey.html Public Gardens of Minnesota http://horticulture.coafes.umn. edu/gardens/home.htm Tree Link Tree Search Trees Are Good University of Minnesota Forestry Library Wetland Plants and Plant Communities of Minnesota and Wisconsin resource/1998/mnplant/ mnplant.htm

Native Trees for North American Landscapes. Guy Sternberg and Jim Wilson. 2004. Timber Press. Planting Nature: Trees and the Manipulation of Environmental Stewardship in America. Shaul E. Cohen. 2004. University of California Press. Red Sky at Morning: America and the Crisis of the Global Environment. James Gustave Speth. 2004. Yale University Press.

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

Wildland Recreation Policy. J. Douglas Wellman and Dennis B. Propst. 2004. Krieger Publishing. ADVOCATE • Fall 2004


Minnesota Shade Tree Advocate A quarterly newsletter published by the Minnesota Shade Tree Advisory Committee. Managing Editorial Group: MnSTAC Education Committee (Gary R. Johnson, Mark Stennes, Jeff Rick, Ken Holman, Patrick Weicherding, James Burks and Emily Barbeau) Editor-in-Chief: Judy Slater 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:

Landscaping with Native Trees from p. 14 Transplant the seedlings in the spring after one or two year’s growth. Choose their permanent site carefully. Soil texture, drainage, and pH should be similar to conditions they experience growing wild. Moisture, temperature and light levels must also be considered. Water young trees weekly (unless there’s ample rainfall) during the first few years after transplanting. Control pests and weeds to reduce competition. Spread three to four inches of woodchip mulch over the root area to help reduce weed growth and conserve moisture. To prevent sunscald, wrap tree trunks each autumn until they develop corky bark, but be sure to remove the tree wrap early each May. Provide rodent protection by encircling young tree trunks with a cylinder of quarter-inch mesh hardware cloth. The mature size of native trees is influenced by many factors including light, water, soil, fertility, competition and length of growing season. They are often taller under forest conditions than when grown in an open area. More information about trees native to Minnesota is available from the Minnesota Landscape Arboretum ( and the University of Minnesota Extension Service ( Reference: Young, J.A. and C.G. Young Seeds of Woody Plants in North America. Dioscorides Press, Portland, OR .1992

Judy Slater Minnesota Shade Tree Advocate 115 Green Hall 1530 Cleveland Ave. N. St. Paul, MN 55108 Printed on recycled paper using soy-based inks.

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