Best Management Practices

Tips to Acquire Desired Tree Species

By: Abby Krause, Western Region Urban Forestry Coordinator,  

Hoping to avoid the repeated destruction from Dutch elm disease (DED) and emerald ash borer (EAB), a new wave of planting initiatives focuses on species diversity. However, acquiring species to meet these diversity goals is often easier said than done. Below are some tips based on comments and feedback from nurseries and other tree managers to help your tree ordering process go smoother in the future.

  • Know B&B (Balled and Burlapped) seasonality. Some species are harvested from the fields in spring only because they do not tolerate having their roots disturbed later in the season. If these species sell out at the beginning of the year, they will not be available again until the following year. Prioritize B&B spring dug species for spring orders or check the availability of container-grown stock for later in the year. Your nursery supplier will be able to elaborate on which of their offerings are exclusively spring dug.
  • Specify (spec) by caliper and not DBH. Both are measures of tree diameter, so what’s the difference? Caliper is predominantly measured at 6 inches above the soil, while DBH (diameter at breast height) is measured at 4.5 feet. While DBH is used in other parts of urban forestry (think inventories, wood volume, etc.), caliper is the go-to when referring to nursery stock. You may have difficulty finding large enough stock if you’re using DBH by mistake.
  • Don’t specify species included in NR 40 (the invasive species rule). First, you don’t want to use species that can become problematic in the natural areas of your community. Secondly, some nurseries cannot bid on proposals that include invasive species because of their company procedures and will end up rejecting your entire proposal.
  • Be flexible (but firm) on species substitutions. What was the main reason behind your original species selection: Do they handle tough soil conditions, maximize stormwater interception, and provide wildlife habitat? Will another species accomplish the same primary goal? Keep in mind the 5-10-15 Diversity Rule. Your urban tree population should include no more than 5% of any one species, 10% of any one genus, and 15% of any one family. Knowing why a tree was selected will allow you to make an informed decision on potential substitutions and prevent you from planting an unsuitable tree for the site simply because it was the only thing available.
  • Be flexible on stock size. Nurseries noted that people tend to prefer 1.75-2.00” caliper stock. Will a slightly smaller or larger stock size work for your planting site? Smaller trees can be easier to work with and additionally establish and start putting on new growth faster. Larger trees need a longer water maintenance plan, but their size can help deter vandalism in high-traffic areas and add instant aesthetics.

Credit: Alfo Medeiros, Pexels

  • Seedlings in natural areas. Response to storms/pests/disease, stormwater mitigation, and the addition of no-mow areas are a few instances that may spur planting in community natural areas. Using bare root seedlings often makes the most financial and logistical sense in these instances. Natural areas also offer locations to plant trees that may be less desirable along roads and trails but still help increase the community’s overall species diversity. Native seedlings are available each spring from private nurseries and the DNR nursery, with orders typically opening each October for spring delivery.
  • When in doubt, call and ask. Calling nurseries to ask about their species availability for the upcoming season and future years can help plan your planting projects. Trees need time to grow to reach their salable size. When a species you’re interested in is not readily available, inquire if it’s currently being grown and when it will be ready for purchase. If it’s not being grown, let the nursery know it’s a species you’d be interested in acquiring in the future. The 2020 Diverse Urban Tree Species Survey results highlight the availability and success rate of lesser-used species in Wisconsin communities.
  • Let nurseries know if you’re open to trying new species. While chatting with your local nurseries about the species you’d like to see available, make them aware if you’re also open to trying new species. Nurseries are interested in the performance of new species in the landscape before they scale up production. The City of Stevens Point’s Forestry Department tests new species in a local park before using them
  • Contract grows for known upcoming projects. Most municipalities don’t meet the minimum quantity requirements for contract grows with their regular annual plantings. However, it may be viable for projects like a new park or major street redevelopment. Exploring the feasibility of splitting a contract grow with a neighboring community may be another way to meet the minimum thresholds.
  • Don’t wait to order. Lastly, a simple tip but perhaps the most important of them all: For the best-guaranteed selection, plan on having your trees ordered they will be going in the ground. The earlier, the better if there are specific species and sizes needed. With the high demand for trees, some communities even order trees in the fall for their spring planting season.  

Twolined Chestnut Borer Attacks On The Rise

By Paul Cigan, DNR Forest Health Specialist, Hayward, or 715-416-4920

Twolined chestnut borer (TLCB) attacks on oak trees have increased in numerous Wisconsin counties, with decline and associated mortality in the last two growing seasons, most noticeably since August.

Symptoms of infestation by this native beetle are initially seen in mid-July on the outer portions of branches in the upper crown. Leaves begin to fade from green to yellow to red. Within a matter of weeks, they turn brown and remain on the branches for weeks to months. Their foliage may also appear sparse or completely bare (Fig. 1).

Trees with twolined chestnut borer symptoms

Figure 1. Northern red oaks with symptoms of twolined chestnut borer, ranging from crown thinning and leaf chlorosis like the tree on the left (early stage) to dead top branches like the tree on the right (intermediate stage). Photo: Wisconsin DNR

Continue reading “Twolined Chestnut Borer Attacks On The Rise”

Look For Spongy Moth Egg Masses – Larger Outbreak Possible in 2023

By: Bill McNee, DNR Forest Health Specialist, Oshkosh or 920-360-0942

Three tan-colored spongy moth egg masses on a single tree branch in Walworth County.

Three spongy moth egg masses on a branch in Walworth County. Photo Credit: Bill McNee, Wisconsin DNR

Now that spongy moth* (formerly known as gypsy moth) egg laying is complete for 2022, it’s a good time to look for and dispose of egg masses produced by adult moths over the past two months.

Spongy moth egg masses are tan-colored lumps about the size of a nickel or quarter, and are found on trees, buildings and other outdoor objects. They may also be found in protected places such as firewood piles and birdhouses. Newly produced egg masses will feel firm and appear darker in color than older egg masses, which appear faded, feel spongy and do not contain viable eggs. The current-year egg masses will not hatch until next spring.

In 2022, Wisconsin’s spongy moth population grew for a third consecutive summer due to favorable weather conditions and limited caterpillar mortality from diseases. The outbreak was most dramatic in opposite ends of the state. In southern and southeast Wisconsin, several thousand oak-dominated acres were heavily defoliated and very large numbers of property owner reports were received by DNR staff. In Bayfield County, about 80,000 acres of rural defoliation was reported from aspen-dominated forests. Smaller patches of defoliation were also reported from several other counties. Continue reading “Look For Spongy Moth Egg Masses – Larger Outbreak Possible in 2023”

Find New Trees to Plant with the Iverson Park Tree Map

A Fort McNair Horse Chestnut. The tree is one of 31 trees identified as underused or uncommon in Iverson Park. Credit: Stevens Point Forestry Department

The Stevens Point Forestry Department has created an interactive GIS map called Iverson Park Trees. This map allows a self-guided tree walk that identifies 31 trees that are underused or not common in the area to help residents learn about uncommon trees they can incorporate in to their private property.

The interactive map focuses on Iverson Park’s value as a tree evaluation site. The Stevens Point Forestry Department test plants specific tree species here for a few years to see how well they do before the department decides to buy large quantities of the species and place them throughout the city. Continue reading “Find New Trees to Plant with the Iverson Park Tree Map”

Studies Find Small Urban Forests Can Help Cool Cities

Heat waves are no joke. Temperatures can increase to a dangerous level, exacerbating existing health issues, induce heat stroke, and can even result in death. Increased temperatures do not affect all communities evenly, however.

Studies have found that the highest temperatures and the most heat-related deaths occur in urban areas. Concrete, asphalt, and other paved surfaces often readily absorb and release heat, causing a phenomenon known as an urban heat island effect.

Urban land managers have the potential to mitigate some of this heat island effect with the types of foliage they incorporate into their landscape designs.  Studies find that tree canopy cover can provide shade that reduce the heat absorbed in paved surfaces and lower surface temperature in general. However, many policies that try to implement urban forests as cooling effects focus on large green spaces, which are often not feasible in urban areas. Continue reading “Studies Find Small Urban Forests Can Help Cool Cities”

EAB Identified For The First Time In Forest And Ashland County

By Linda Williams, DNR Forest Health Specialist, Woodruff,, 920-360-0665 & Paul Cigan, DNR Forest Health Specialist, Hayward,, 715-416-4920

Emerald ash borer (EAB) has been detected for the first time in Forest County in the Town of Armstrong Creek and Ashland County in the City of Ashland. The Forest County detection was most likely a natural expansion of other infestations in Florence and Marinette counties.

Bark has been removed from an ash tree to show EAB tunnels present near the base of the tree.

This Forest County tree was infested with EAB top to bottom. Photo: Wisconsin DNR

The Ashland County detections appear to be isolated infestations likely spread through the transportation of firewood or logs. Several large green ash stands in the City of Ashland show advanced infestation signs.

EAB was first found in Wisconsin in 2008. There are now just seven counties where EAB has not yet been identified. EAB was federally deregulated as of January 2021. In 2018, Wisconsin instituted a state-wide quarantine. This discovery in Forest and Ashland counties will result in no regulatory changes.

Please visit the interactive Wisconsin EAB detections map to see where EAB has been reported. Follow the map’s instructions if you know of an infested area not on the map. Continue reading “EAB Identified For The First Time In Forest And Ashland County”

Invasive plant management on roadsides workshops

Invasive plants have been shown to impact Wisconsin’s economy, environment and human health. Roadsides are a key area where these unwanted plants establish and spread. These right of way habitats are challenging to work in but focused efforts can be successful in preventing spread and reduce invasive plant populations.

To help educate and jumpstart management, The University of Wisconsin-Madison Extension along with 4-Control are conducting roadside invasive plant workshops throughout the state. We invite you to attend one of these five regional workshops. While this training is available to anyone interested, the focus will be on training staff of municipalities that manage vegetation on roadsides. Continue reading “Invasive plant management on roadsides workshops”

Public comment period for EAB silviculture guidelines revision closes October 9

By Bill McNee, forest health specialist, Oshkosh.; 920-360-0942

Ash trees dying from an EAB infestation. Photo: Troy Kimoto,

Ash trees dying from an EAB infestation. Photo: Troy Kimoto,

The Wisconsin DNR is seeking public comments on a proposed revision to silviculture guidelines for emerald ash borer (EAB). Stand-level EAB silviculture guidelines were originally released in 2007, with periodic reviews and updates. A DNR technical team and stakeholder advisory committee prepared the current version using multiple sources of information, including recent research findings, identification and locations of new EAB infestations, economic considerations, and experience gained from implementing previous versions of the guidelines.

The draft document and information about the public comment process can be found at through Tuesday, October 9, 2018. All comments must be submitted by that date.

BMPs found to protect water quality

Map of 2015 BMP Monitoring Sites on private, nonindustrial forestland in Wisconsin

The Wisconsin forestland sites monitored by the 2015 BMP teams. Coniferous trees represent sites that were in the Managed Forest Law (MFL) program and deciduous trees represent sites not in the MFL program. Note: Some dots are close together making the total number of sites difficult to determine on this map.

Newly-released results from 2015 monitoring for the application and effectiveness of Wisconsin’s Forestry Best Management Practices (BMPs) for Water Quality show excellent results. The effectiveness of BMPs that were applied correctly was extremely high (99.6%) at protecting water quality, but when BMPs were applied incorrectly or not applied, BMP effectiveness rates woefully dropped (6.3% and 9.4% respectively).  Even with the low water quality protection of BMPs that were applied incorrectly and not applied, no major impacts were reported on any of the monitored sites.   Read more details about the results from the monitoring of 36 non-industrial private forestland (NIPF) sites (26 of the landowners are enrolled in the MFL program) in the 2015 BMP Monitoring Report.

For more information, contact Forest Hydrologist Dave Kafura,, (715) 416-4140