Purdue University - Extension - Forestry and Natural Resources
Meet the Hawthorns, a family of small trees with wide-ranging features that make it difficult to tell various species apart. Learn about this group of native Indiana trees, which produce beautiful spring blooms, from Purdue Extension forester Lenny Farlee in this episode of ID That Tree.
If you have any questions regarding wildlife, trees, forest management, wood products, natural resource planning or other natural resource topics, feel free to contact us by using our Ask an Expert web page.
Resources:
ID That Tree, Playlist, Purdue Extension – Forestry and Natural Resources YouTube Channel
A Woodland Management Moment, Playlist, Purdue Extension – FNR YouTube Channel
Shrubs and Woody Vines of Indiana and the Midwest, Purdue University Press
Native Trees of the Midwest, Purdue University Press
Investing in Indiana Woodlands, The Education Store
Forest Improvement Handbook, The Education Store
Lenny Farlee, Sustaining Hardwood Extension Specialist
Purdue University Department of Forestry and Natural Resources
Starting in May, the Indiana Department of Natural Resources (DNR) began to receive reports of sick and dying songbirds from several counties around the state. As of now, the cause of the illness remains a mystery although submitted specimens have tested negative for avian influenza and West Nile virus according to the DNR. Affected birds have white crust and discharge around the eyes and damage to their nervous system. Reports of sick birds have expanded to many more counties in Indiana.
Several diseases that affect songbirds are transmitted from one animal to another. Bird feeders can increase the likelihood of disease transmission by facilitating close contact among birds. Even though the disease and its mode of transmission in this case is unknown, the DNR is recommending all Hoosiers remove their birdfeeders.
Officials recommend the following steps:
The Audubon Society recommends the following best practices:
Resources:
DNR recommends removal of birdfeeders statewide – June 25, Indiana Department of Natural Resources
Birdfeeder tips, The National Audubon Society
Birds and Residential Window Strikes: Tips for Prevention, The Education Store, Purdue Extension resource center
Breeding Birds and Forest Management: the Hardwood Ecosystem Experiment and the Central Hardwoods Region, The Education Store
Managing Woodlands for Birds Video, Purdue Extension-Forestry and Natural Resources YouTube Channel
Brian MacGowan, Wildlife Extension Specialist
Purdue University, Department of Forestry and Natural Resources

Question:
I live in central Indiana and have had no cicadas yet. Are they still emerging or is it safe to uncover my tender trees?
Answer:
If you haven’t seen or heard any 17-year cicadas near your trees yet, there probably won’t be any emerging there this year. You should be safe to take off the netting now, but I’d still suggest learning the signs of cicada egg laying damage and keeping an eye on any trees you’re worried about. The damage typically looks like a row of small holes in the bark connected by cracks (exp. periodical cicada (Magicicada septendecim) but it can vary depending on the species of plant. If you see signs of egg laying damage, you can put the netting back on to protect your trees from any additional injury.
Resources:
Billions of Cicadas Are Coming This Spring; What Does That Mean for Wildlife?, Got Nature? Blog, Purdue Extension-Forestry and Natural Resources (FNR)
17 Ways to Make the Most of the 17-year Cicada Emergence, Purdue College of Agriculture
Ask an Expert: Cicada Emergence Video, Got Nature? Blog, Purdue Extension-FNR
Periodical Cicada in Indiana, The Education Store, Purdue Extension resource center
Cicada Killers, The Education Store
Purdue Cicada Tracker, Purdue Extension-Master Gardener Program
Elizabeth Barnes, Exotic Forest Pest Educator
Purdue University Department of Entomology
The swallow-worts (also called dog strangling vine) are perennial, herbaceous, twining vines. The two species of principal concern in North America are black and pale swallow-wort. Black swallowwort is native to southwest Europe; pale swallow-wort is native to Ukraine and parts of Russia. Both were introduced to North America in the 1800s as potential ornamental plants.
Although swallow-worts are not yet well established in Indiana, their vines are highly invasive and grow vigorously, quickly twining around, and will climb anything nearby such as trees and shrubs or even man-made structures. This can overwhelm nearby plants by physically shading them, weighing them down, causing stem breakage, and forcing them to compete for moisture and nutrients.
At the time of writing, nine counties in central and northern Indiana reported small populations of black swallow-wort ranging in size from 10 square feet to 2,500 square feet of the infested area. Along Indiana’s border, two Michigan counties and the Chicago area report significant populations of black swallow-wort. No records of pale swallow-wort have been reported for Indiana. Two Michigan counties bordering northern Indiana and a central Illinois county are the nearest reported populations of pale swallow-wort.
This publication, Invasive Plant Series: Swallow-worts, aids in identifying these swallow-worts and provides management recommendations focused on prevention of spread, early detection, and properly timed and targeted control measures.
Resources:
Invasive Species, Playlist, Purdue Extension YouTube Channel
Invasive Plants Threaten Our Forests Part 1: Invasive Plant Species Identification, Webinar, Purdue Extension – Forestry and Natural Resources YouTube Channel
Invasive Plants Threaten Our Forests Part 2: Control and Management, Webinar, Purdue Extension – FNR YouTube Channel
Indiana Invasive Species Council
Report Invasive, Purdue Extension
The GLEDN Phone App – Great Lakes Early Detection Network
EDDMaps – Early Detection and Distribution Mapping System
Indiana Department of Natural Resources: Invasive Species
Indiana Invasive Species Council
Cooperative Invasive Species Management Area (CISMA)
Invasive plants: impact on environment and people, The Education Store, Purdue Extension resource center
Invasive Plant Species Fact Sheets: Poison Hemlock, The Education Store
What are invasive species and why should I care?, Got Nature? Blog, Purdue Extension – Forestry and Natural Resources
Ronald Rathfon, Regional Extension Forester Southern Indiana Purdue Agriculture Center (SIPAC)
Purdue Department of Forestry and Natural Resources
In this episode of ID That Tree, Purdue Extension forester Lenny Farlee introduces you to the flowering dogwood, which blooms in April and May, and is a great alternative to the invasive callery pear. Learn more about this small tree and its growing preferences inside.
If you have any questions regarding wildlife, trees, forest management, wood products, natural resource planning or other natural resource topics, feel free to contact us by using our Ask an Expert web page.
Resources:
ID That Tree, Playlist, Purdue Extension – Forestry and Natural Resources YouTube Channel
A Woodland Management Moment, Playlist, Purdue Extension – FNR YouTube Channel
Shrubs and Woody Vines of Indiana and the Midwest, Purdue University Press
Native Trees of the Midwest, Purdue University Press
Investing in Indiana Woodlands, The Education Store
Forest Improvement Handbook, The Education Store
Flowering Dogwood, The Purdue Arboretum Explorer
Flowering Dogwood, Native Trees of Indiana River Walk, Purdue – Fort Wayne
Lenny Farlee, Sustaining Hardwood Extension Specialist
Purdue University Department of Forestry and Natural Resources
In this episode of A Woodland Management Moment, Purdue Extension forester Lenny Farlee shares about some of the spring ephemeral plants, as well as shrubs, trees and even invasive species you may find in the forest understory.
If you have any questions regarding trees, forests, wildlife, wood products or other natural resource topics, feel free to contact us by using our Ask an Expert web page.
Resources:
A Woodland Management Moment, Playlist, Purdue Extension – Forestry and Natural Resources (FNR) YouTube Channel
ID That Tree, Playlist, Purdue Extension – FNR YouTube Channel
Invasive Species, Playlist, Purdue Extension – FNR YouTube Channel
Garlic Mustard, Purdue Extension – FNR YouTube Channel
Invasive plants: impact on environment and people, The Education Store, Purdue Extension resource center
Shrubs and Woody Vines of Indiana and the Midwest, Purdue University Press
Native Trees of the Midwest, Purdue University Press
Investing in Indiana Woodlands, The Education Store
Forest Improvement Handbook, The Education Store
Woodland Invaders, Got Nature? Blog
Resources and Assistance Available for Planting Hardwood Seedlings, The Education Store
Woodland Stewardship for Landowners Video Series, Playlist, Indiana Department of Natural Resources YouTube Channel
Lenny Farlee, Sustaining Hardwood Extension Specialist
Purdue University Department of Forestry and Natural Resources
A program launched across the U.S. on June 1st by the company NCX (formerly called SilviaTerra) is enrolling woodland owners at no cost. The company pays landowners for the carbon captured through postponing harvest for one year.
Landowners can go to the NCX landowners website to learn more about the program and enroll. Simply create an account and identify your property boundaries and submit your application for an analysis of your land’s potential.
NCX uses a large database of US forest inventory to analyze and model harvesting and market information, and will determine the risk of harvest for your property in the next year. If their data shows there is “X” tons of carbon in your trees at risk of harvest in the next year, and you sign up and defer that harvest for a year, you can be paid for the carbon captured by that deferment. If they determine there is no harvest at risk, a landowner can’t participate. A landowner can also choose to defer a portion of the total, which would allow them to thin or harvest some of the property, while deferring other areas.
When considering whether to sign up for this or any carbon payment program, landowners should consider a few factors:
Resources:
A New Carbon Program for Hardwood Landowners, June 15th, 2021, Webinar, Walnut Council YouTube Channel
An Introduction to Forest Carbon Offset Markets, Publication, North Carolina State Extension
NCX carbon program for landowners, NCX Carbon Exchange – Landowners
Family Forests Carbon program, American Forest Foundation
Carbon market policy initiatives, American Forest Foundation
Liz Jackson, Manager Walnut Council / IN Forestry Woodland Owners Association (IFWOA) & Engage Specialist
Purdue University Department of Forestry and Natural Resources
Purdue Landscape Report: Pruning is an important maintenance practice on trees that is discussed a great deal. An essential part of making the pruning cut properly is the ability to identify the parts of a branch. Identification of the branch bark ridge and branch collar are vital to severing the branch in a place that facilitates fast and effective wound closure, reducing decay in the location of the cut.
Branches on trees arise from lateral buds present in leaf axils. Initially, lateral shoots (branches) grow in length and diameter at approximately the same rate as the parent stem. As branches become shaded naturally by crown expansion, photosynthesis is reduced in that location and growth slows to a lesser rate than the parent or main stem. A swollen area or collar develops at the junction of branch and stem because of their differential growth rates and by the intermingling of vascular tissues from both the branch and the stem or trunk.
This swollen area is commonly referred to as a branch collar and often present in many branches on the underside of the branch. This specialized location on the branch is composed of trunk (parent stem) wood. The branch collar contains a protective chemical zone that inhibits the movement of decay organisms from dead or dying branches into healthy tissues of the parent stem. As branches begin to die from shading, pests or storm damage, for examples, they usually are walled off (compartmentalized) by tissues in the branch collar which prevents movement of decay organisms into the parent stem.

Identify the branch collar and branch bark ridge to perform a good cut, which is just outside the line.
Another important branch component to identify in tree branches is the branch bark ridge. This part of the attachment is composed of rough, usually darkened, raised bark formed at the union where the branch meets the parent stem. The ridge extends from the top of the branch down both sides of the branch union. Together with the branch collar, the portion of the ridge pushed up in the union provides our target for the pruning cut. The BBR is present on every branch union and is an important identifying feature for determining tool placement.

An internal view of the branch collar and branch bark ridge revealing the intermingled stem and branch wood fiber.
The combination of the branch collar, branch bark ridge, and the overlap between the branch and stem are the branch components that form what is called the branch protection zone. This zone contains specialized chemical compounds that help resist the spread of disease in the tree and facilitate wound-sealing. Always avoid damaging the area within the branch collar and branch bark ridge to help the tree recover from the pruning cut as quickly as possible.

The Branch Protection Zone is an area that contains specialized chemicals to assist with the healing process after pruning.
For the best advice on tree maintenance and care, seek out a tree care professional with the experience and expertise to care for your trees. Search for a tree care provider in your area. Also, consider hiring an ISA Certified Arborist which can be found here.
Resources:
Planting Your Tree Part 1: Choosing Your Tree, Purdue Extension YouTube Channel
Tree Planting Part 2: Planting a Tree, Purdue Extension YouTube Channel
Tree Selection for the “Un-natural” Environment, The Education Store, Purdue Extension resource center
Tree Installation: Process and Practices, The Education Store
Tree Pruning Essentials Video, Purdue Extension YouTube Channel
Purdue Landscape Report
Lindsey Purcell, Urban Forestry Specialist
Purdue Department of Forestry and Natural Resources
Purdue Landscape Report: While fungi are responsible for many of our foliar disease problems, different fungal pathogens present as problems throughout the country, depending upon the host plant grown and the environmental conditions. This is a brief overview of several common types of fungal leaf diseases that occur in Indiana and throughout North America (and Europe). Recognizing the symptoms and signs is an important first step to diagnose a disease problem, followed by how to manage these diseases by combining cultural and chemical controls.
Common fungal leaf diseases of deciduous trees and shrubs
Anthracnose. Anthracnose diseases probably are the best-known foliar fungal diseases of deciduous trees. They affect many ornamental trees including major shade-tree genera such as sycamore (Platanus spp.), oak (Quercus spp.), maple (Acer spp.), elm (Ulmus spp.) and ash (Fraxinus spp.) (Fig. 1). Anthracnose actually is a general term describing symptoms such as dead irregular areas that form along and between the main vein of the leaf. The leaves may also become curled and distorted and twigs may die back. The fungus overwinters in infected twigs and the petioles of fallen leaves, and the spores disseminate in the spring by wind and splashing rain. The disease, while unsightly, rarely results in the tree’s death. Sycamores and other trees often withstand many years of partial defoliation. However, one anthracnose disease is more serious. Dogwood anthracnose (Discula destructiva) is a devastating problem on the Eastern seaboard, but has not been a significant issue here in Indiana.
Leaf blisters result in the blistering, curling and puckering of leaf tissue. Oak leaf blister (Taphrina caerulescens) is a common blister disease of oaks (Fig. 2)., particularly the red oak subgenus, which includes Northern red oak (Q. rubra) and pin oak (Q. palustris) among others. The symptoms begin as a slight yellowing of the infected leaf followed by round, raised blisters. These turn brown, and the infected leaves fall prematurely. This fungus overwinters as spores on the buds.
Leaf spot is a general symptom caused by a multitude of pathogens and infect all deciduous trees and shrubs, and include dead spots with a defined boundary between living and dead tissue. The dead tissue often separates from the surrounding living tissue creating a “shot-hole” appearance on the infected leaves. Common hosts include dogwood, maples, hydrangea, rose, holly, and Indian-hawthorn.
Tar spot (Rhytisma spp.) is a leaf disease with initial symptoms similar to leaf spot. The disease is most common on red (Acer rubrum) and silver maple (A. saccharinum) (Fig.3), but it can occur on a wide range of maple species from sugar (A. saccharum) and Norway (A. platanoides) to bigleaf maple (A. macrophyllum). The symptoms begin in the spring as small greenish-yellow spots on the upper leaf surface that, by mid-summer, progress to black tar-like spots about 0.5 inch in size. The disease is not fatal to the tree, but the appearance of the tar spots alarms some tree owners. A major outbreak in New York about 10 years ago left many maples completely defoliated by mid-August.
Resources:
Diplodia Tip Blight of Two-Needle Pines, The Education Store, Purdue Extension resource center
Boxwood Blight, The Education Store
Disease of Landscape Plants: Cedar Apple and Related Rusts on Landscape Plants, The Education Store
Planting Your Tree Part 1: Choosing Your Tree, Purdue Extension – Forestry & Natural Resources (FNR) YouTube Channel
Tree Planting Part 2: Planting a Tree, Purdue Extension – FNR YouTube Channel
Find a Certified Arborist, Trees are Good-International Society of Arboriculture (ISA)
Video: Step by Step to Find an Arborist, Trees are Good-International Society of Arboriculture (ISA)
Professional Forester, Indiana Forestry Woodland Owners Association
District Forester, Indiana Department of Natural Resources, 10+ acres
Trees and Storms – The Education Store
Why Is My Tree Dying? – The Education Store
Tree Risk Management – The Education Store
Tree Pruning Essentials, Publication & Video, The Education Store
Tree Wound and Healing, Got Nature? Blog, Purdue Extension – FNR
What are Invasives Species and Why Should I Care?, Got Nature? Blog, Purdue Extension – FNR
Subscribe – Purdue Extension-FNR YouTube Channel
Janna Beckerman, Professor of Plant Pathology
Purdue Department of Botany and Plant Pathology
Question: My hackberry trees are dropping leaves for no apparent reason. The leaves look fine, no bugs or mold spots or discoloration of any kind. Do you have any idea what might be causing the leaf drop?
Answer: The loss of leaves on hackberries in spring is an occasional phenomenon in the Midwest. The exact cause has never been determined. In past years, no association was found between the leaf drop and insects or diseases. The most popular theory is that cold spring temperatures may have damaged the leaf buds or newly developing leaves, causing the leaf drop. Remember that blast of winter in April!? It’s likely the loss of leaves in spring is temporary. In past years, affected hackberries quickly developed new leaves and recovered completely. Just be patient and wait for the reflush of growth.
Leaves may be falling from your maple trees right now. This is a common spring issue caused by the maple petiole borer. Look closely at the fallen leaves for abnormally short petioles and examine the tree canopy for broken petioles that have remained attached. Although sugar maples are generally preferred, other maples may occasionally be infested. Fortunately, while the leaf drop may appear dramatic, the actual impact on the overall health of affected trees is minimal, so controls are not necessary. Also, a re-flush of leaves may be expected.
Resources:
Will My Tree Recover After Losing Their Leaves, Purdue Landscape Report
Planting Your Tree Part 1: Choosing Your Tree, Purdue Extension YouTube Channel
Planting Your Tree Part 2: Planting A Tree, Purdue Extension YouTube Channel
Tree Installation: Process and Practices, The Extension Store, Purdue Extension resource center
Ask an Expert: Tree Selection and Planting, Purdue FNR Extension YouTube Channel
Find a Certified Arborist, International Society of Arboriculture (ISA)-Trees Are Good
Lindsey Purcell, Urban Forestry Specialist
Purdue Department of Forestry and Natural Resources