Beginning July 2023, The City of Highland Park will be utilizing a new portal for all permitting applications. CIVIC ACCESS, will act as a one-stop shop for all residential and commercial permitting needs. More information can be found under the "Tree Removal Permit Applications" tab below. Please contact Forestry with any questions.
The Forestry Section maintains approximately 30,000 street and public trees throughout the City of Highland Park. Tree care includes planting, pruning, integrated pest management and removal of hazardous parkway trees. In addition, the Forestry Section manages the landscaping and grounds of over 150 City-owned properties including City Hall, train stations, and business districts. The Forestry Section is also responsible for permitting development to preserve trees during construction and the care of vegetation within ravines and bluffs for compliance with the City of Highland Park Tree Preservation Ordinance.
In 2023, the Arbor Day Foundation named the City of Highland Park a Tree City USA for it's 43rd year! As one of the longest standing members of this group, it shows the city's deep-rooted commitment to the preservation of its urban forest.
For additional information, please review the topics below or contact Forestry Section staff.
Tree Removal Permit Applications
An approved tree removal permit is required for any tree, dead or alive, ≥8" in diameter (measured at ~4.5' above the soil) or ≥15" aggregate diameter for multi-stem trees.
Removal of ANY vegetation within the "Steep Slope Zone" (as defined by Chapter 150 of Highland Park City code) requires an approved tree removal permit application. Please contact Forestry for more information.
Tree Removal Permit Applications may be submitted through Highland Park's online Civic Access Portal.
Civic Access Portal:
The City of Highland Park uses an online permitting and licensing portal for all administrative applications. Residents, property managers and contractors can now complete all permit applications, including tree removal permit applications, using the link above. All permit information can conveniently accessed within the applicant's account.
Please register an account with Civic Access go to www.cityhpil.com/permitsandlicenses to setup your self-service portal account. Once an application is submitted, all future communications (including permit status and the approved permit placard) will be available within the self-service portal.
Construction & Trees
Under City of Highland Park code, any construction project in Highland Park must take the existing landscape into consideration, specifically the trees. Highland Park’s tree preservation ordinance requires that healthy and desirable trees be preserved where possible. This is determined during the review process, before construction is permitted. The Public Works - Forestry Section works very closely with the Department of Community Development - Building Division to review construction projects for tree preservation requirements.
This review includes trees on the subject property, as well as adjacent parcels. A tree preservation plan (including a survey and inventory) is required to ensure any adjacent trees that will be preserved through construction will be excluded from construction activity. This is most often accomplished by creating a “tree preservation area” using wood lathe or chain link fence as a physical barrier. Depending on the extent of construction, this may be supplemented by other mitigation practices such as laying down plywood or a thick layer of much (12-18 inches) where equipment has to pass through a Critical Root Zone.
Trees Preservation & Construction in Highland Park Pamphlet
Below is a list of common construction practices that can damage trees. The Forestry Section reviews construction for all of these items and more:
|Heavy Equipment Operation
|Changing Drainage Patterns
Tree Replacement Requirements:
Removal of healthy trees from private property in Highland Park may require the property owner/developer to plant new trees. Typically, this occurs in conjunction with a re-landscaping or construction project. The required number and specie of replacement trees is dependent on the quantity and type of trees removed.
The City of Highland Park-Code Plant Palette includes species appropriate for Highland Park and accepted as construction replacement.
Please note that this document is updated regularly and may change on a routine basis.
What are "Protected", "Key", and "Heritage" Trees?
Under Chapter 94 of Highland Park city code, three levels of tree preservation are identified and assigned to trees based on specie and size determinations. The tiered structure for this classification reflect the need for added consideration to be given when managing desirable & native trees. Giving preference to tree species that thrive in and have been integral to landscape of this community; as well as mature, established individuals that define urban forest of Highland Park.
Prior to the removal of any Protected, Key, or Heritage tree within Highland Park, requires an submission and approval of a Tree Removal Permit Application. This application is reviewed by the City of Highland Park's Forestry Section of Public Works for compliance with the City's tree preservation ordinance. In addition, an application for the removal of any Heritage tree, must first be reviewed by the City of Highland Park Zoning Board of Appeals.
Although any tree, determined by City staff, to be dead, dying, diseased or hazardous is not be subject to tree removal fees or tree replacement requirement, an approved tree removal permit application is still required.
These classifications are as follows:
"Any Tree having a diameter of eight inches (8") DBH or larger or having an Aggregate Diameter of 15 inches DBH or larger, except any tree in the genera Rhamnus (Buckthorn) or Salix (Willow)."
"Any Protected tree of the following genera or species:
- Acer saccharum (Sugar Maple);
- All trees in the genus Carya (Hickory);
- Taxodium distichum (Bald Cypress);
- Celtis occidentalis (Hackberry);
- Ginkgo biloba (Ginkgo);
- Gymnocladus dioicus (Coffee tree);
- All trees in the genus Juglans (Walnut)
- Pseudotsuga menziesii (Douglas Fir);
- Pinus strobus (White Pine);
- Picea abies (Norway Spruce);
- Quercus velutina (Black Oak);
- Quercus macrocarpa (Burr Oak);
- Quercus alba (White Oak);
- Quercus rubra (Red Oak);
- Quercus bicolor (Swamp White Oak).
"Any Tree of the following genera or species:
- All trees in the genus Quercus (Oaks) greater than or equal to 30" DBH;
- Ulmus Americana (American Elm) greater than or equal to 40" DBH;
- All trees in the genus Carya (Hickory) greater than or equal to 20" DBH;
- All trees in the genus Juglans (Walnut) greater than or equal to 30" DBH
More information on Highland Park's tree preservation ordinances can be found HERE or by contacting the Forestry Section at 847.432.0807.
Tree Preservation Ordinances: Fines/Citations
Compliance with the City's tree preservation ordinance is crucial to maintaining the health and longevity of Highland Park's urban forest.
Failure to do so may result in the issuance of citations by City staff based on the nature of the violation and extent of damage to Protected, Key, and/or Heritage trees. These citations may require the appearance before a judicial officer in conjunction with the City of Highland Park's Administrative Adjudication system. Any fines leveed against a respondent are at the discretion of the judicial officer based on the nature of the infraction and scope of damage.
Example violations may include:
|Removal of Protected, Key, or Heritage trees without benefit of permit
|$1,000 per Protected or Key tree removed
$4,000 per Heritage tree removed
|Failure to maintain tree preservation measures during construction
|$1,000 per violation*
|Excavation, operation of heavy equipment, or material storage within the driplines of trees
|$1,000 per violation*
|Removal or damaging vegetation within the steep slope zone without benefit of permit
|$4,000 per violation
|Failure to remove tree infested with Dutch Elm Disease
|Failure to remove a tree deemed a hazard to the City right-of-way
More information on Highland Park's tree preservation ordinances can be found HERE or by contacting the Forestry Section at 847.432.0807. You can also access the City's Annual Fee Resolution, that includes all Chapter 94/150 (Tree Preservation Ordinances) fees and fines HERE.
Green Dots on Trees
As you travel around Highland Park, you may notice that some trees adjacent to City streets are marked with a green dot. On public streets, the strip of land adjacent to the edge of the street is owned by the City, even on streets without a sidewalk. This strip of land is the public right-of-way and most often referred to as the ‘parkway.’
The green dots are placed on trees to allow Forestry staff and City contractors to better identify publicly maintained trees. Each year, in preparation for routine parkway tree pruning, all trees within a scheduled section of Highland Park are re-inventoried and all "green dot" markings are refreshed. For this reason, some dots in town may appear greener and brighter than others.
For more information on the City's parkway tree pruning program, please see below.
Parkway Tree Pruning
Routine tree pruning is an important component of Highland Park’s tree maintenance program. To maintain a routine pruning cycle, the City is divided into eight regions with each region containing approximately the same number of trees. Each Winter (typically January-April), parkway trees within one of these regions are pruned. Parkway tree pruning is conducted according to ANSI A300 Standards to prune young trees for proper form and structure, to maintain tree health, to reduce risk to life and property, and to provide necessary clearance for vehicular and pedestrian traffic.
2024 Parkway Tree Pruning - Region 2
Tree Pruning Regions
If you have any questions concerning the work or contractors, please contact the Forestry Section at 847.432.0807.
Health & Maintenance of Trees
Mulching & watering are the easiest ways to improve the health of your trees.
- Add mulch to the base of your tree after removing grass within a 3-10' radius of the trunk (based on the size of the tree)
- Place natural mulch (such as wood chips or bark pieces 2-4" in depth in a ring about the trunk
- Do not pile mulch against the trunk, as this will promote rot in the tree (Volcano Mulching)
- Add more mulch every 2-3 years as necessary
- Water the tree until the soil is moist, not soggy. Too much water is just as harmful as too little
- Infrequent, deep watering is better than frequent light watering. Evaporation (especially in hot weather) means most water will not make it to your tree if it isn't deeply watered
- The best time of year to prune is the winter
- The worst time of year to prune is early Fall or Spring, when fungal diseases are most prevalent.
- If you are unsure if your trees need pruning, a Certified Arborist can help.
Tree Planting Guide
Planting Native Species
There are many reasons why your next landscaping projects should include native species. Native species generally require less maintenance as they are adept at dealing with ecological and environmental conditions in this area. Overall, the survivability of natives is higher and requires fewer chemical inputs, such as fertilizer and pesticide, for them to thrive in your garden. Unlike annuals that die each Autumn, native perennials do not require replacement year after year to maintain a well-stocked landscape. In fact, many spread and multiple, saving money. In addition to hosting many of our pollinating insects, mammals, and birds they also aid in combating many conditions of urban development. These include erosion (particularly in ravines and bluffs), flooding/storm water management, and combating invasive species encroachment.
Since 2010, the City of Highland Park has made the use of native species central to our planting initiatives. The McClory Bike Trail Pollinator Garden project aims to replace invasive buckthorn along the trail with native, pollinator friendly species (like Milkweed). Beyond a natural area, natives can also be a staple within formal landscape design. This can be seen in a number of recent City projects such as at City Hall and an increasing number of traffic islands within the Central Business District.
|First Street Island
|McClory Trail Pollinator Garden
|Laurel Avenue Underpass
Invasive species, such as buckthorn and bush-honeysuckle grow vigorously and form dense thickets.These weedy shrubs shade out under story vegetation and out-compete native species for resources. Although these shrubs function as privacy screening between homes, many native shrubs and trees serve the same function without the detrimental side effects to your landscape.The Chicago Region Trees Initiative has compiled a list of "Healthy Hedges"; native alternatives to invasive species that function as excellent vegetative screening.
SELECTING NATIVE PLANTS FOR RAVINE OR BLUFF RESTORATION
North shore ravines and bluffs were historically covered with many plant species. To maximize success of your restoration, choose plants adapted to your local shade, moisture, and temperature conditions. Strive to purchase plants that were grown locally from seeds or stock harvested close to the Illinois Lake Michigan shoreline. Please note that this list is not intended to be exclusive or comprehensive, and it is recommended that you first seek advice from a licensed landscape architect or arborist to determine which plants are most suitable for your property. When planting, please ensure that landscaping debris is hauled off site and not deposited into the ravines.
Select Native Ravine Plants for Restoration
For further information on native species and steep slope restoration, please contact the City Forester at 847.926.1179.
Buckthorn and Other Invasive Plants
Invasive plants are those which are both non-native and that spread aggressively. Norway spruce is non-native, however it rarely or never ‘escapes captivity’ to reproduce freely in the wild (in the Midwest); it usually only grows where we plant it intentionally and thus is not invasive. Norway maple, on the other hand, is an example of a non-native tree that has easily escaped captivity and now reproduces freely here in Highland Park (more on Norway maple below).
Non-native plants spreading through your yard or garden may not be concerning, or may even be a desired trait. However, invasive plants tend to disrupt natural ecosystems such as our ravines and bluffs. Invasive plants often outcompete native plants for space in the environment, and because they are non-native, they almost always provide significantly less ecological benefit. Our native insects have coevolved with many native plants, and in some cases are dependent upon each other. Reducing space for native plants can mean reducing habitat (food and reproduction ability) of native insects such as the Monarch Butterfly.
Invasive plants cause other types of problems in the environment as well such as soil erosion. Listed below are several invasive species common in Highland Park that the Forestry Section is monitoring and in many cases taking action against.
Morton Arboretum invasive plants
The term "Invasive species" is frequently overused. It has become a pejorative phrase, often aimed at non-native flora and fauna, regardless of said species' actual impact on the urban forest.
Each year, the rate at which we hear about novel insects, pathogens, and plants' impacts escalates exponentially. These troublemakers include Garlic Mustard, Emerald Ash Borer, Burning Bush, Dutch Elm Disease, Garlic Mustard, and the newcomer Spotted Lanternfly, to name a few. We face a bombardment of new plants, insects, and diseases threatening our ecosystems and landscapes. The constant influx leads to complacency and acceptance as we become numb to the prospect of managing yet another intruder in our natural world.
Yet, one species truly deserves the label "invasive" and all the stigma it brings. It has become the most abundant and pervasive pest across Lake County. It might even be in your own backyard.
Glossy & Common Buckthorn (Rhamnus sp.) is a woody shrub found in Highland Park and throughout northern Illinois. The City of Highland Park and Park District of Highland Park have worked to eradicate this aggressive shrub from public lands for decades. Affected areas include Gateway Park, "The Preserve", Sesquicentennial Park, Heller Nature Center, and many other parks and preserves. Since 2017, reducing buckthorn populations and reintroducing native, pollinator-attracting species of shrubs, trees, and wildflowers has been at the core of the McClory Bike Trail Pollinator Garden initiative. To date, this project has removed nearly 8 acres of Buckthorn.
However, the majority of Highland Park's Buckthorn resides on private property. As stewards of the urban forest, residents must understand the terrible nature of Buckthorn, recognize it in the wild, and control buckthorn encroachment as part of regular landscape maintenance.
What is Buckthorn?
European settlers brought Buckthorn to North America in the mid-1800s, making it one of the first invasive species introduced to the United States. Its purpose - hedgerows, an integral component of formal European landscaping to which they were accustomed and wished to replicate here. These settlers found that the plant not only filled that role well but thrived in its new climate. Lacking any predators to keep the population in check, Buckthorn quickly escaped the landscape setting and subsumed woodland habitats.
Buckthorn is a cunning species. Often, it quietly grows in forgotten areas of our community, where it can be left alone to thrive. In Highland Park, it flourishes along property lines where minimal or no landscaping is done for fear of losing vegetative screening or because ownership is in question. Larger stands take root in unmanaged or minimally managed landscapes, such as wooded stands, ravines, bluffs, and riparian areas.
Why is Buckthorn a problem?
Buckthorn quickly invades and supplants any understory vegetation. It forms dense thickets that choke out native species with shade. Buckthorn is the first of our woody shrubs to leaf out in the spring and the last to lose foliage. This extended growing season gives it an edge when competing with native flora. Its aggressive growth habits also make maintenance of Buckthorn a costly endeavor, sometimes requiring pruning multiple times within a single growing season to prevent obstructions to sidewalks, driveways, or sight lines in an urban setting.
Even more problematic, Buckthorn exudes allelopathic chemicals from its roots. These compounds alter the chemistry of the soil, curtailing the growth of native vegetation and negatively impacting seed germination adjacent to Buckthorn stands. Unfortunately, the allelopathic effects remain for years after removing the Buckthorn.
Native shrubs serve as food and habitat for 35 times as many North American insects as non-native woodies like Buckthorn. But across the Chicago region, Buckthorn sp. accounts for 52% of the vegetative canopy (Chicago Region Trees Initiative, www.chicagorti.org), far more prevalent than species such as Oaks, Maples, Spruce, or Viburnum. The collapse of native insect populations has been directly correlated to this displacement of native plant communities by invasives like Buckthorn. Many plants, songbirds, and mammals rely on these insects for food and other ecosystem services such as pollination.
Buckthorn sprouts readily from seed. Typically, this spread is accomplished through consumption by birds, but the berries provide little nutritional benefit. The berries are a noxious purgative which is toxic to mammals. The laxative properties ensure that seeds will remain intact once digested and dispersed.
How do I identify Buckthorn?
Buckthorn is a tall, typically multi-stemmed, understory shrub. At maturity, it can reach 20' in height, often with a spreading canopy. Several prominent characteristics can help you identify a buckthorn, including:
Dark green, egg-shaped leaves. Foliage is present before most other plant species in the spring and persists late into fall/winter months
Prominent thorns on the trunk & limbs that give buckthorn its name
Clusters of dark black berries persist into winter on female individuals. Not all specimen have berries
Cambium (or Inner bark) exhibits bright orange color. Unique characteristic, not shown by any other species in our area.
How do I get rid of Buckthorn?
Newly sprouted or recently established populations of Buckthorn may be cut and smothered using opaque materials such as cardboard, garbage bags, or tarps. You can pull or dig out saplings but must remove as much root mass as possible to prevent future re-sprouts.
Well-established, mature populations or thickets of Buckthorn may require additional measures to ensure control methods extend to the roots. Options include stump grinding to weaken the plant further and discourage growth or the application of herbicides for systemic regulation. Large-diameter buckthorn will re-sprout even after cutting, so herbicide is often a necessary component of a management regime. Herbicide must be applied conscientiously to minimize chemical risks and prevent collateral damage to desirable vegetation.
When dealing with any invasive species, it is essential to tailor your management plan to your situation. While minor infestations can be handled by an average homeowner with gardening skills, larger or dense stands may require speaking with a Certified Arborist, landscaper, or Ecological Restoration contractor. These specialists typically have the experience, personnel, equipment, and herbicides to address your situation.
For more information or assistance identifying Buckthorn on your property, contact Ben Miller, City Forester, at email@example.com or 847.926.1179.
Lake County Forest Preserve District: How to identify/eradicate Buckthorn (The Buckthorn Stops Here!)
Chicago Region Trees Initiative: Native alternatives to Buckthorn (Healthy Habitat Series)
City of Highland Park: (Find a Licensed Landscape Professional in Highland Park)
Japanese Knotweed is a perennial herbaceous plant native to Japan, China, and Korea. The hollow stems look like bamboo, but is unrelated. It grows very quickly and spreads horizontally in a very aggressive manner. It is very tough and can grow in disturbed, low quality soils. A piece of the plants stalk or root system only 1” square can be washed down streams and rivers to start a new colony, making it commonly found along rivers where it is spread easily during flood events. It is also commonly spread around by landscapers, hitching a ride on their equipment.
Where Japanese Knotweed grows near the foundation of a home or garage, or the edge of hardscape such as a driveway, the plant can quickly undermine structural integrity of these structures. It does this by exploiting tiny cracks and growing through them, widening them. Its vast underground network of fleshy rhizomes are difficult to eradicate with herbicide and even more difficult to manually dig out. Leaving behind even a small portion of rhizome means the plant will likely grow back.
The World Conservation Union lists it as one of the top 100 worst invasive species in the world. Here in Highland Park, we have found it in ravines, on bluffs, and in vegetative screens between neighbors and along property lines. The ground around knotweed colonies is often barren of organic material, leaving the soil vulnerable to erosion. Considering we often find this plant growing along waterways such as our rivers and ravines (because it is easily moved around in flood events), the potential for soil erosion is very concerning. The City is currently monitoring more than 20 colonies of Japanese Knotweed in Highland Park, and working to eradicate 5-6 of those with herbicide treatment applied by licensed professionals.
Norway maple is native to Northern Europe and is a popular tree in the Chicago area. It is currently ‘not recommended’ by the Morton Arboretum due to its habit of spreading aggressively. Here in Highland Park, they are popular with homeowners who often plant the variety with red leaves (incorrectly referred to as ‘red maples’). The City planted them extensively as street trees in the 1970s through the 1990s. However, we are now systematically removing them and replacing them with other species because of their invasive nature. They are also not long-lived, they are not resistant to rot and decay, and they are not resistant to storm damage.
Norway maple produces numerous wind-borne seeds that have aggressively invaded our ravines where they produce a heavy, dense shade that interferes with and prevents growth of native herbaceous perennials, such as our native grasses and wildflowers. These native grasses and wildflowers are deep-rooted and play an important role in the stability of steep slopes. Norway maple causing the absence of these native plants is a threat to ravine slope stability. Due to the invasive nature of this species and its effect on our ravine ecosystem, Norway maples put on a removal permit will be eligible for reduced replacement requirements and fees.
Ravine & Bluff Restoration
Two unique features of Highland Park's landscape are it's winding ravines and towering bluffs overlooking Lake Michigan. The ravines and bluffs provide invaluable ecological, structural, and financial benefits to the residents of Highland Park.
City code allows for the management and maintenance of the Steep Slope Zone, but there are strict regulations in place to ensure that Best Management Practices are followed. The ravines and bluffs, known as "Steep Slope Zone" under Chapter 150 of Highland Park City code, are sensitive to disturbance and caution needs to be taken when working or planning to work in these areas.
The City, along with the Park District of Highland Park, has developed a guide to Maintaining Ravine and Bluff Vegetation in the Steep Slope Zone.
Before working in the Steep Slope Zone, it is important to consult with a professional and contact the Department of Public Works Forestry Section for permit requirements. An approved permit is required for the removal of any vegetation (includes for landscaping, ecological restoration, or construction purposes) within the Steep Slope Zone. Topping trees to improve a view is forbidden.
For information related to ravine and bluff maintenance work or permit requirements for tree care, please see Tree Removal Permit Applications above.
McClory Bike Trail Pollinator Garden
The Robert McClory Bike Path (a.k.a. The Green Bay Trail) is a 25 mile trail connecting many of the communities along Lake Michigan in the northern suburbs of Chicago. The City of Highland Park has partnered with the Park District of Highland Park to create the McClory Bike Trail Pollinator Garden. The overarching goal of this initiative is the conversion of the primary cover from invasive vegetation to native species of shrubs, wildflowers, and trees. This will greatly improve the ecological value of this land by providing habitat to pollinating insects, birds, and animals while reducing maintenance cost incurred by invasive vegetation encroachment on the trail.
As with many forest patches in the North Shore, the invasive shrub Buckthorn (Rhamnus cathartica) has become the dominant species in the understory, choking out beneficial native shrubs and perennial wildflowers. Buckthorn also influences overstory trees as it forms dense thickets, limiting what tree seedlings germinate and thrive. This has profoundly impacted the regeneration of many of our native hardwood trees in Highland Park’s Oak/Hickory forests.
This invasive shrub spreads readily and quickly forming monoculture stands, shading out and outcompeting natives for light and resources. With its rapid growth habit, additional financial burdens are created by the spread of this vegetation into walking paths, sidewalks and streets. Thereby requiring significant annual expenditures to remediate obstructions. This impact is present in park district properties, forest preserves, City rights-of way, and private property.
Buckthorn can also cause seriously detrimental consequences in our ravines and bluff where limiting the growth of deep rooted natives can compromise structural stability of steep slopes. Recognizing the threat posed by invasive species (such as Buckthorn, Honeysuckle, garlic mustard, Japanese Knotweed, etc...) groups such as the Park District of Highland Park, The Friends of the Green Bay Trail, and Lake County/Cook County Forest Preserve Districts have sought to eliminate invasive species from their public lands.
In 2017, Highland Park received a ComEd Green Region grant to create pollinator friendly habitat along the McClory Bike Trail. Removal of invasive Buckthorn, Honeysuckle, and Norway Maple began Autumn 2017. Planting began Spring 2018 and still occurs each Spring and Autumn. City and Park District staff along with volunteers from Northwood Middle School and Highland Park High School have installed plugs, shrubs, and trees across two acres of the bike trail. A plan is being prepared to extend this effort to all 30 acres of public land adjacent to the bike trail.
For more information on this project or to volunteer at an upcoming event, please contact the Forestry Section at 847.432.0807.
Northwood Gives Back @ Lincoln Place (9.26.2019)
Spring 2018-Summer 2019
City Pesticide Usage
The City of Highland Park has made a commitment, through the Sustainability Plan, adopted by City Council in 2010, to reduce or eliminate the use of synthetic chemicals (e.g., pesticides and fertilizers). Accordingly, no "weed and feed" products or herbicides will be used on City maintained turf, except for those classified by the United States Environmental Protection Agency as exempt materials under 40CRF 152.25, or those pesticides of a character not requiring FIFRA regulation (e.g., horticultural vinegar). City wide, fertilizer use must comply with the City’s ban on phosphorus. Organic fertilizers are preferred as an alternative (e.g., organic compost for turf, mulch for flower beds).
For example, the City no longer sprays turf grass with pre or post-emergent herbicides to prevent dandelions or insecticides to prevent grubs and other ‘turf pests.’ Weed management in turf areas is accomplished by hand-pulling, or spot treating with organic herbicides such as essential oil-based, vinegar-based, fatty acid products, or increasing the frequency of the mowing cycle. Examples of products used include the brands Burnout or Phydura. Spot-treatment of weeds in hardscape areas, such as the brick pavers in the Central Business District, is accomplished by hand-pulling or spraying horticultural vinegar.
The City will use synthetic chemical-based herbicides to control aggressive, invasive species such as Buckthorn, Japanese Knotweed, and Phragmites. The treatments are typically associated with ecological restoration where invasive species need to be controlled for new native vegetation to establish. The application of these chemicals is performed by contractors meeting qualification and reference standards, as well as holding State of Illinois Commercial Pesticide Application/Operation licenses. Notification, application, and rate usage must comply with labelling guidelines and all applicable laws and regulations.
Emerald Ash Borer (EAB)
Emerald ash borer (EAB) is a wood-boring beetle native to Southeast Asia (China and Korea). It was discovered in Michigan in the summer of 2002, having been accidentally introduced via wood packaging materials (e.g., wood shipping pallets). EAB larvae feeds on ash trees, quickly resulting in tree mortality. State and local governments made significant efforts to eradicate and contain the insect. Despite this, EAB has spread to 28 states and the future of our native Ash population appears uncertain.
Ash Tree Removal
The City’s Forestry Section stopped planting ash trees in 2003 once it was understood EAB would not be quarantined in Michigan. Since 2011, when EAB was discovered here in Highland Park, the City has been removing ash trees located on public property. Ash trees made up approximately 15% of our street tree population in 2011, but as of summer 2020 are down to about 1% of street trees. Though treatment to prevent Emerald Ash Borer attack on ash trees is possible, it is not financially feasible on a city-wide scale. However, homeowners should consult a Certified Arborist as preserving their ash may make sense.
Ash that have been attacked and killed by EAB should be removed promptly to reduce risk to life and property. Small dead Ash often fail at ground level and fall over. Large dead Ash can also fail entirely, after first dropping large limbs. The City encourages residents to proactively remove any potentially unsafe tree(s) including those on or very close to property lines. In these situations, it is important to work with your neighbor.
Dutch Elm Disease (DED)
What is Dutch Elm Disease?
Dutch Elm Disease (DED) is a vascular disease affecting all species of elm. However, our native American Elm (Ulmus americana) is most severely affected by this fungus.
American Elm leaf
Identifying Dutch Elm Disease
The most apparent symptom of DED is a characteristic wilting of leaves. These wilting leaves will first turn yellow and hang from the branch (much like a flag without a breeze). The “flagging” leaves will subsequently turn brown and prematurely drop. Often fallen leaves can be found on the ground below infected elm trees, in the late spring and summer months, particularly in hot/humid weather.
In the early stages of infection, flagging is typically isolated to a single branch of the tree. In later stages of infection branch dieback will extend into a larger portion of the tree’s canopy, until eventually the tree will succumb to the disease.
Characteristic wilting leaves on elm trees known as “flagging”, are indicative of Dutch Elm Disease. Flagging appears in hot weather during the growing season, before autumn leaf drop would set in.
Tunnels from the Elm Bark Beetle leave a unique starburst pattern.
Dutch Elm Disease in Highland Park
As trees infected with DED pose a significant likelihood of passing the disease on to adjacent Elm trees, Highland Park City Code requires the removal of DED infested elm trees on private property. This is called a ‘sanitation program’ and it limits the chance that the disease can spread to other healthy Elms on private or public property. Each year the Forestry Section monitors public and private property for signs of trees infected with DED. Once identified, property owners are notified of the infestation.
Despite the presence of DED, Elms are an important component to the urban forest of Highland Park. DED resistant varieties of Elms are routinely incorporated into the Highland Park’s tree planting programs. Although no specie of elm is totally immune to DED, cultivars of the American Elm have been produced that are very resistant to DED.
Preventing Dutch Elm Disease
Most often, the fungus that causes DED is transmitted from an infected tree to other elms by the Elm Bark Beetle. This insect will pick up the fungus after hatching inside an infected Elm or infested firewood and will move on to healthy Elm trees to feed. In the process, infesting a new host with the disease.
Although healthy trees can be treated to prevent DED, there is no cure. Once a tree has been infected, the fungus can persist. Trunk Injection of fungicide and removal of infected branches is the best method to preserve a tree with DED, if diagnosed early on. If you suspect that your tree may be infected, contact a Certified Arborist to discuss your options. If you cut down a tree due to DED, do not store logs from infected elm trees near healthy elms on your property or near your neighbor’s elms. The disease can still spread once the tree is cut down.
A Certified Arborist can help you identify American Elm trees on your property and help you get ahead of possible DED infestations. The City's Landscaper Licensing program includes a list of Certified Arborists licensed to work in Highland Park.
Realtor Guide for Forestry Concerns
BUYING OR SELLING A HOME - DID YOU INSPECT THE TREES?
When marketing a home for sale, most sellers will either disclose any known issues up front, or perform repairs around the house to get the most value out of their home. One area that is often overlooked with a home inspection is the landscaping on the property, in particular, the trees.
The health and proximity of the trees to the house is an important feature not to be overlooked. Any remedial maintenance efforts, after the sale of home, could be costly and potentially dangerous if there are diseased or dead trees on the property.
A good example of this would be standing dead or dying trees that are infested with either Emerald Ash Borer or Dutch Elm Disease. Removal of these trees may involve a significant investment to keep the property safe. And at certain times of the year, identifying these trees may be very difficult by an untrained eye. Both Emerald Ash Borer and Dutch Elm Disease are well established in Lake County and Highland Park.
A careful inspection of the landscaping and trees on a property can help you sell your home or help avert any unexpected future costs. The City recommends contacting a Certified Arborist to assess the trees and identify any potential concerns on the property.
If you are considering the purchase of a new home that would involve significant construction (e.g., additions, demolition and re-development) we strongly recommend you consult us on tree impacts before-hand. As the removal of trees is regulated by Highland Park City Code, please contact the Forestry Section at 847.432.0807 if you have any questions regarding tree preservation or removal.
Value of Trees
Trees Increase Property Values
Real estate values increase when trees beautify a property or neighborhood. Trees can increase the property value of your home by 10-15%.
(Kathleen L. Wolf. 2008. City Trees and Property Values. Facility Management Journal. pp 120 – 124.)
Trees Produce Oxygen
The urban forest acts as a giant filter that cleans the air we breathe. In one season, an acre of trees produce as much oxygen as 10 people inhale in a year.
Trees Are Carbon Sinks
To produce its food, a tree absorbs and locks away carbon dioxide in the wood, roots and leaves. Carbon dioxide is the main greenhouse gas responsible for global warming. A forest acts as a “sink” or storage area to absorb some of our CO2 emissions.
Trees Clean the Soil and Purify Water
Trees can store harmful pollutants or even change the pollutant into less harmful forms. Trees filter chemicals thereby cleaning water runoff that flows into streams.
Trees Control Noise Pollution
Trees are very effective at reducing noise pollution by 5-10 dB or greater.
(https://greenblue.com/na/trees-as-sound-barriers/) (Ow, Lai Fern, and S. Ghosh. "Urban cities and road traffic noise: Reduction through vegetation." Applied Acoustics 120 (2017): 15-20.)
Trees Clean the Air
Trees help cleanse the air through their respiration. They intercept airborne particles and absorb pollutants like CO, SO2, & NO2.
(Nowak, David J., Daniel E. Crane, and Jack C. Stevens. "Air pollution removal by urban trees and shrubs in the United States." Urban forestry & urban greening 4.3-4 (2006): 115-123.)
Trees Fight Soil Erosion
Tree roots hold soil together and their leaves break the force of wind and rain on soil. Trees and grasses are critical to ravine and bluff slope stability.
Trees and Temperature Control
Shade from trees reduces the need for air conditioning. Studies have shown that urban environments without shade trees form "heat islands" where temperatures can be nearly 12°F higher than surrounding areas. In winter, trees act as a wind break, lowering heating costs.
(Edmondson, J., Stott, I., Davies, Z. et al. Soil surface temperatures reveal moderation of the urban heat island effect by trees and shrubs. Sci Rep 6, 33708 (2016). https://doi.org/10.1038/srep33708)