Got Nature? Blog

Welcome to “ID That Tree.” In this edition, Purdue Extension Forester Lenny Farlee introduces us to an autumn olive shrub found across Indiana. This dense shrub requires extensive control and management due to its effects on the habitat. Watch the video to learn about its aggressive growth, wildlife impact, leaf pattern, and other features!

 

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 – Video Playlist, Purdue Extension – Forestry and Natural Resources (FNR) YouTube Channel
Purdue Arboretum Explorer
Conservation Tree Planting: Steps to Success, Purdue Extension – FNR YouTube Channel
A Woodland Management Moment, Playlist, Purdue Extension – FNR YouTube Channel
Woodland Stewardship for Landowners, Playlist, Purdue Extension – FNR YouTube Channel
Indiana Department of Natural Resources: Invasive Species
Indiana Invasive Species Council
Cooperative Invasive Species Management Area (CISMA)
Report Invasive, Purdue Extension
101 Trees in Indiana, Amazon
Episode 11 – Exploring the challenges of Invasive Species, Habitat University-Natural Resource University
Shrubs and Woody Vines of Indiana and the Midwest, The Education Store
Native Trees of the Midwest, The Education Store
Professional Forester, Indiana Forestry Woodland Owners Association
Forest Improvement Handbook, The Education Store
Find an Arborist, International Society of Arboriculture

Lenny Farlee, Extension Forester
Hardwood Tree Improvement and Regeneration Center
Purdue Department of Forestry & Natural Resources

---

The Purdue Plant and Pest Diagnostic Laboratory (PPDL) proudly presents its latest Annual Report, offering a comprehensive overview of the year’s most significant insights, diagnostics, and trends. This essential document covers critical topics such as spruce-tordon uptake, hosta virus X, ophiostoma ulmi, diamond back moth, lettuce slime mold, and bentgrass dollar spot. As an indispensable resource for growers, researchers, and the public, PPDL remains at the forefront of providing expert analysis on plant diseases, insect identification, and environmental concerns throughout Indiana and beyond.

Visit the PPDL Annual Reports webpage to find the 2024 report and view past reports.

About PPDL:
The Plant and Pest Diagnostic Laboratory (PPDL) remains dedicated to helping protect Indiana’s agriculture, the green industry, and individual landscapes, by providing rapid and reliable diagnostic services for plant disease and pest problems. PPDL also provides appropriate pest management strategies and diagnostics training. They are a participating member lab in the National Plant Diagnostic Network (NPDN), a consortium of Land Grant University diagnostic laboratories established to help protect our nation’s plant biosecurity infrastructure.

Resources:
Find an Arborist, International Society of Arboriculture
Diseases in Hardwood Tree Plantings, The Education Store, Purdue Extension’s resource center
Fifty Common Trees of Indiana
An Introduction to Trees of Indiana
Shrubs and Woody Vines of Indiana and the Midwest, The Education Store
Tree Installation: Process and Practices, The Education Store
Forest Improvement Handbook, The Education Store
Invasive Species, Playlist, Purdue Extension – FNR YouTube Channel
Report Invasive Species, Purdue Invasive Species
What are invasive species and why should I care?, Got Nature? Blog, Purdue Extension – Forestry and Natural Resources
Indiana Department of Natural Resources: Invasive Species
Indiana Invasive Species Council
ID That Tree, Purdue Extension-FNR YouTube playlist
Tree Defect Identification, The Education Store
Tree Wound and Healing, Got Nature? Blog, Purdue Extension – Forestry and Natural Resources

Purdue Plant & Pest Diagnostic Laboratory (PPDL)
Purdue Botany and Plant Pathology

---

Join David and Mary Ray on a tour of their award winning forest in southwest Jackson County! The Rays are hands-on managers of their beautiful southern Indiana oak forest, and are excited to share the results of their management strategies with you!

Registration is required for this FREE EVENT. To register call or email Let the Sun Shine In – Indiana, Judi Brown, coordinator, 812-631-4904, JBrown@abcbirds.org. Registration is due April 3rd. Please share any dietary restrictions if needed.

Date: April 5, 2025
Time: 9:30am to 1:00pm EDT
Location: David & Mary Ray Property, Southwest Jackson County, 5 miles SW of Medora, event signs will be posted

Schedule:
Onsite Registration: 9:00 AM
Forestry Tour: 9:30 to Noon
Lunch: 12 to 1 PM, sponsored by Indiana Forestry and Woodland Owners Association (IFWOA)
Maple Sap Gathering 1 PM, optional

Speakers Include:
David Ray, Property Owner
Dan McGuckin, ACF, CF, CWB
Dan Shaver, NRCS State Forester
Judi Brown, LSSI IN

Take note: This is a walking tour in a hilly forest. Be prepared for rough terrain; please wear appropriate clothing and footwear. Limited on-site transportation assistance available, if needed. In the event of storm rain date is April 12, 2025.

To print flyer and view large map visit: Indiana Forestry & Woodlands Owners Association (IFWOA): Oak Management Forestry Field Day: Jackson County flyer (pdf).

For all IFWOA events and woodland resources view Indiana Forestry & Woodlands Owners Association (IFWOA) website.

Resources:
Indiana Forestry & Woodland Owners Association (IFWOA) YouTube Channel
Deer Impact Toolbox, Purdue Extension Pond and Wildlife Management
District Forester, Indiana DNR Division of Forestry, for over 10 acres of woodlands
Directory of Professional Foresters, Indiana Forestry & Woodland Owners Association (IFWOA)
Indiana Woodland Steward E-newsletters, Eleven Member Organization
A Woodland Management Moment, Playlist, Purdue Extension – Forestry and Natural Resources (FNR) YouTube Channel
Conservation Tree Planting: Steps to Success, Purdue Extension – FNR YouTube Channel
Forest Improvement Handbook, The Education Store
Invasive Species, Playlist, Purdue Extension – FNR YouTube Channel
Woodland Stewardship for Landowners, Playlist, Purdue Extension – FNR YouTube Channel
Invasive Plant Species Identification, Video, Purdue Extension – FNR YouTube Channel
Report Invasive Species, Purdue Invasive Species
ID That Tree – Video Playlist, Purdue Extension – Forestry and Natural Resources (FNR) YouTube Channel
Subscribe – Purdue Extension-FNR YouTube Channel

Liz Jackson, IFWOA engagement specialist & Walnut Council Manager
Indiana Forestry & Woodlands Owners Association (IFWOA)

---

Invasive species are any plant, animal, insect or plant disease not native to a specific location that can cause harm to the environment, impact the diversity of native species, reduce wildlife habitat or disrupt important ecosystem functions.

Why should you care about invasive species? Invasive species limit land use, degrade natural resources and inhibit recreational pursuits such as hunting, fishing, bird watching, and foraging. They also negatively impact fisheries, agricultural and forestry industries, destabilize soil and alter water resources. Invasive species also out compete natives and are costly to control with estimates showing that the U.S. spends $137 billion/year to control/manage invasive species.

As spring approaches, many invasive plants will begin to leaf out in woodland areas. Spring is a good time to stop them in their tracks so they don’t overtake native plants, affect water availability or damage the quality of soil among other potential impacts.

Here are some resources to help you identify various invasive plants in woodland areas near you, to know when to report them and also what you can do help control their spread.

Videos on Purdue Extension – Forestry and Natural Resources (FNR) YouTube Channel, Invasive Species Playlist

• Asian Bush Honeysuckle
• Burning Bush
• Callery Pear
• Multiflora Rose
• Invasive Plants Threaten Our Forests Part 1: Invasive Plant Species Identification
• Invasive Plants Threaten Our Forests Part 2: Control and Management

Don’t miss this YouTube Shorts video, Lenny Farlee Talks About Invasive Plants Emerging in Early Spring

More Purdue Extension-FNR YouTube Video Series –
Woodland Management Moment Videos:

• Against Invasives
• Garlic Mustard
• Autumn Olive

Woodland Stewardship for Landowners Videos:

• Common Buckthorn
• Japanese Barberry

ID That Tree Videos:

• Invasive White Mulberry
• Invasive Siberian Elm
• Invasive Tree of Heaven
• Invasive Amur Honeysuckle
• Asian Honeysuckle

FNR Extension Publications, The Education Store:

• Invasive Plant Species: Oriental Bittersweet
• Invasive Plant Species: Wintercreeper
• Japanese Chaff Flower
• Kudzu in Indiana
• Mile-a-minute Vine

Purdue Landscape Report:

• Alternatives to Burning Bush for Fall Color
• Now is the Time to Identify Callery Pear
• Keyword search: Invasive

FNR Extension Got Nature? Blog:

• Woodland Invaders
• Invasive Species: the Good News and the Bad News

When and how do I report an invasive species?
The Purdue Invasive Species website will help you identify invasive species and explain how to send in your findings. If you notice something is killing an otherwise healthy stand of trees or shrubs, you will want to identify it and report it if it is on the invasive list. If you see a plant that is taking over an area where it doesn’t belong, you will want to identify it and report it if it is on the invasive list.

• The GLEDN Phone App – Great Lakes Early Detection Network
• EDDMaps – Early Detection and Distribution Mapping System
• 1-866 No EXOTIC (1-866-663-9684)
• depp@dnr.IN.gov – Email Indiana Department of Natural Resources (DNR)

More Resources
Indiana Department of Natural Resources: Invasive Species
Indiana Invasive Species Council
Cooperative Invasive Species Management Area (CISMA)
Aquatic Invasive Species, Illinois-Indiana Sea Grant (IISG)
Episode 11 – Exploring the challenges of Invasive Species, Habitat University-Natural Resource University
Emerald Ash Borer Information Network, Purdue University and Partners
What Nurseries Need to Know About the Invasive Species Regulation, The Education Store, Purdue Extension’s resource center
Invasive plants: impact on environment and people, The Education Store, Purdue Extension’s resource center

Diana Evans, Extension and Web Communication Specialist
Purdue University Department of Forestry and Natural Resources

Lenny Farlee, Extension Forester
Hardwood Tree Improvement and Regeneration Center
Purdue Department of Forestry & Natural Resources

---

Purdue Landscape Report: Dieback and canker diseases caused by Botryosphaeria, Sphaeropsis, Diplodia and other closely related fungal pathogens are exceptionally common on woody landscape plants. This group of diseases are often referred to collectively as Botryosphaeria diseases and this article will follow that convention to discuss them as a group. Examine any mature oak tree long enough and you’re likely to find at least some stems dying due to Botryosphaeria. Check the base of dying stems of cranberry bush viburnum and you’re likely to find a Botryosphaeria canker. Look closely at sunken cracked stems and dieback on redbud and, you guessed it, more Botryosphaeria.

Botryosphaeria is opportunistic and is often seen killing individual branches that have been wounded or attacked by other diseases, providing an entry point for the fungus. (Fig 1) Stress factors like drought, freezing or defoliation due to disease or insect attack increases susceptibility to infection, and reduces plant defenses so that existing infections often move faster down the stem. However, wounds are not required for infection. In susceptible trees and shrubs, the fungus may attack the smallest twigs and later spread to larger branches where they cause cankers.

Symptoms:
Discoloration and death of leaves on individual stems may point to Botryosphaeria canker at the base of the dying stem (Fig 2). As the canker girdles a stem, the portion of the stem above the canker gradually dies. Smaller twigs with immature bark may become discolored as the pathogen spreads. Symptoms may vary depending on the plant species infected. In many cases the infection fails to completely encircle the stem, resulting in stems with half necrotic and half living stem tissue (Fig 3).

Botryosphaeria cankers usually cause bark to be cracked, sunken and discolored (Fig 4). Fruiting bodies of the fungus appear as pinhead-sized black specks embedded in the bark, which may be raised in small bumps covering the cankers.

Management:
Prevention of infection depends mainly upon avoiding unnecessary wounding and minimizing environmental stresses that induce susceptibility. Avoid allowing trees and shrubs, especially those recently transplanted, to become drought stressed. Keep plants in good condition and in moderate growth. Avoid high fertilizer rates that induce rapid, succulent growth that may be more susceptible to infection.

Prune out and destroy any dead branches at least six inches below discoloration in the bark or sapwood. Be sure to clean pruning tools with a disinfectant after working on infected plants.

Fungicides have not been effective at preventing infections, and once the fungus is inside the wood fungicides can’t touch it, so they are generally not recommended in the landscape.

Avoid using highly susceptible plants, such as Viburnum trilobum or Salix spp., in drought prone sites.

Resources:
Botryosphaeria Canker, Purdue Plant Doctor
Beat Back Borers Attacking Pines, Purdue Landscape Report
Black Spot of Elm, Purdue Landscape Report
Inonotus Dryadeus – Butt and Root Rot of Oaks, Purdue Landscape Report
Stories in the Bark – Patterns and Growth, Purdue Extension – Forestry & Natural Resources Got Nature? Blog
Root Rot in Landscape Plants, The Education Store, Purdue Extension resource center
Dead Man’s Fingers, Purdue Landscape Report
ID That Tree Fall Color: Sugar Maple, Purdue Extension – Forestry and Natural Resources (FNR) YouTube Channel
ID That Tree Fall Color Edition: Black Gum, Purdue Extension – FNR YouTube Channel
An Introduction to Trees of Indiana, The Education Store
Tree Defect Identification, The Education Store
Tree Wound and Healing, Got Nature? Blog, Purdue Extension – FNR
Shrubs and Woody Vines of Indiana and the Midwest, The Education Store
Ask an Expert: Tree Selection and Planting, Purdue Extension – FNR YouTube playlist
ID That Tree, Purdue Extension – FNR YouTube playlist
Invasive Species, Playlist, Purdue Extension – FNR YouTube Channel
Report Invasive Species, Purdue Invasive Species
Find an Arborist, International Society of Arboriculture
Subscribe, Purdue Extension – FNR YouTube Channel

Tom Creswell, Plant & Pest Diagnostic Laboratory Director
Purdue Botany and Plant Pathology

---

Weekly Review, Division of Entomology & Plant Pathology, Indiana DNR: Will Drews, Indiana Department of Natural Resources (DNR) Nursery Inspector & Compliance Officer with the DNR Division of Entomology & Pathology shares in September Weekly Review e-newsletter how staff will continue to help coordinate kudzu control throughout the state and expands upon the state funded kudzu control program.

As some of you may know, kudzu (Pueraria montana var. lobata) is an invasive woody vine that can now be found throughout the state of Indiana. It is referred to colloquially as “the vine that ate the south,” and if you took a drive through some southern states (e.g. Tennessee, Georgia, the Carolinas, etc.) right now, you’d see why. Kudzu has tremendous growth potential, sometimes as much as 1 foot per day. Some vines reach lengths of up to 100 feet. Because of this it is a detriment to Indiana’s natural resources, kudzu has been listed as a prohibited invasive plant under the DNR’s Administrative Code as per 312 IAC 18-3-16 Control of kudzu.

While part of the language includes that the landowner “must take efforts to eliminate this species in such a manner as is consistent with federal and state law,” the Division of Entomology & Plant Pathology have been leading a state funded control program where sites are treated on a rotating, priority basis to eradicate or suppress further spread with no cost to the landowner. Over the last month, around 40 kudzu sites in Indiana have been treated and we have seen some great progress from last year.

If you think you have seen a new kudzu population, please send me that information (photos and GPS coordinates or address) at my email address provided below. A couple of the sites treated this year are new reports from last year that we were able to address. With your help, we can try to reduce the impact of this incredibly invasive vine and protect our natural resources.

For more information regarding this invasive vine Kudzu see the Indiana Department of Natural Resources, Division of Entomology & Plant Pathology, Kudzu.

Subscribe: Entomology Weekly Review.

Resources:
Indiana Department of Natural Resources-Division of Entomology & Plant Pathology
Indiana Department of Natural Resources-Natural Resources Conservation Service Plants Profile
Indiana Department of Natural Resources-National Invasive Species Information Center
Indiana Department of Natural Resources-Kudzu Alert & Identification Sheet
Indiana Department of Natural Resources-Kudzu Fact Sheet
Indiana Department of Natural Resources-Kudzu Before & After Treatment Photos
Invasive Species, Playlist, Purdue Extension – FNR YouTube Channel
Report Invasive Species, Purdue Invasive Species
What are invasive species and why should I care?, Got Nature? Blog, Purdue Extension – Forestry and Natural Resources
Indiana Department of Natural Resources: Invasive Species
Invasive Plant Species Identification, Video, Purdue Extension – FNR Youtube Channel
Mile-a-minute Vine, The Education Store
Invasive Plant Series: Swallow-worts, The Education Store

Will Drews, Nursery Inspector & Compliance Officer, Division of Entomology & Plant Pathology, WDrews@dnr.IN.gov
Indiana Department of Natural Resources (IN DNR)

---

Purdue Landscape Report: As summer comes to a close, plants are rapidly releasing seeds and the most noticeable are the flying fluffy type. Thistles, asters and milkweed are just a few of the summer-flowering plants that depend on the wind to disperse their seeds, sometimes carrying them miles away to potentially suitable locations, though seeds typically land within a few meters of the mother plant. This may not be a concern if it’s a desirable plant, but can become extremely problematic when that seed comes from Canada Thistle (Cirsium arvense) (Fig. 1).

Canada thistle is found on the list of Indiana Noxious Weeds (IC 15-16-7-2), which mandates that landowners take necessary steps to control and contain the spread of this highly invasive species. Formal enforcement of this Indiana Code falls to Township Trustees, though weed control is a responsibility that is often overlooked. Landowners and homeowners shouldn’t wait for a notice, or knock at the door, from a Township Trustee to begin controlling Canada thistle. It’s listed as a noxious weed for good reason.

Canada thistle is a perennial plant that can reproduce from seed or rhizomes making it difficult to control and contain. Each plant can produce thousands of wind-blown seeds that may remain viable for up to 20 years in the soil. Rhizomes are horizontal underground stems that can grow several feet and put out new shoots (Fig. 2). To add insult to injury, if a rhizome is cut or tilled, a separate plant may grow from each piece of rhizome.

Mechanical and cultural control options for Canada thistle are limited and may reduce plant density, but are not effective at eradicating large, established populations in a landscape. A new population, without an established root system, may be controlled with frequent mowing to deplete food reserves and prevent seed production.Small, isolated populations may be controlled with hand-pulling, but this will need to be repeated every few weeks.

Chemical control options include pre- and post-emergent herbicides and, in many cases, applications of both types are needed for complete eradication. A pre-emergent herbicide, with an active ingredient of dichlobenil, is effective at preventing seed from germinating, but will not control established plants. A post-emergent herbicide with the active ingredient of clopyralid is the most effective option for home gardeners. Clopyralid is a selective herbicide for broadleaf weeds, but most vegetable and ornamental plants are susceptible. Precautions should be taken to avoid off-target damage. Read and understand the herbicide label before use. The label is the law.

Regardless of the method used, complete control of an established Canada thistle population will take persistence over multiple seasons. If the fluffy seed is beginning to fly from your thistle patch, it will likely take many more seasons to rid the garden of this pest, but it is possible. To win the battle against Canada thistle, it takes serious grit and an effective herbicide, or a good realtor.

View the original article here: What the Fluff?!

Subscribe and receive the newsletter: Purdue Landscape Report Newsletter.

Resources:
ID That Tree, Playlist, Purdue Extension – FNR YouTube Channel
Find an Arborist video, Trees are Good-International Society of Arboriculture (ISA)
A Woodland Management Moment, Playlist, Purdue Extension – FNR YouTube Channel (Against Invasives, Garlic Mustard, Autumn Olive)
Woodland Stewardship for Landowners, Playlist, Purdue Extension – FNR YouTube Channel (Common Buckthorn, Japanese Barberry)
Planting Your Tree, Video, The Education Store
Tree Installation, The Education Store
Indiana Invasive Species Council
Indiana Department of Natural Resources: Invasive Species
Purdue Extension Pond and Wildlife Management Website
Control of Canada Thistle in CRP and Other Noncrop Acreage, The Ed Store
Invasive Thistles
Report Invasive Species, Purdue Invasive Species
Understanding and Controlling Thistle in the Nursery and Landscape, Purdue Landscape Report
Subscribe – Purdue Extension-FNR YouTube Channel

Karen Mitchell, Consumer Horticulture Extension Specialist
Purdue Horticulture & Landscape Architecture

---

Purdue Landscape Report: There have been a significant number of questions and problems regarding triclopyr that have come up this growing season.

Several of these problems have come through the Purdue Plant and Pest Diagnostic Laboratory from landscapers, nurseries, and property managers.

General Information about Triclopyr
Triclopyr is a selective systemic herbicide belonging to the pyridine class. It is primarily used to manage woody plants, vines, and some broadleaf weeds. Unlike glyphosate, a broad-spectrum herbicide, triclopyr specifically targets the growth hormones in dicotyledonous plants, making it effective in controlling species that are difficult to manage with other herbicides. It works by mimicking plant hormones, disrupting normal growth processes, and leading to the death of the treated plant (Fig. 1).

What Triclopyr Controls
Triclopyr is utilized in various settings to control unwanted vegetation. It is effective against species such as:

• Woody Plants: Includes trees like tree of heaven and callery pear and shrubs like autumn olive and honeysuckle (Fig. 2).
• Vines: Particularly those that can outcompete native flora, such as kudzu or English ivy (Fig. 3).
• Broadleaf Weeds: Some herbaceous plants that pose ecological or agricultural problems.

 

 

 

 

 

 

 

 

Where and When Triclopyr is Used
Triclopyr is applied in a range of environments, including:

• Forestry: To clear invasive species and manage forest regeneration.
• Agriculture: To control weeds and shrubs that interfere with crop production.
• Aquatic Areas: Formulations that are safe for aquatic environments help manage invasive species near water bodies.
• Rights-of-Way: To maintain clear paths and prevent the spread of invasive plants.

Timing of application is crucial. Triclopyr is most effective when applied during the growing season when plants are actively taking up nutrients and can transport the herbicide throughout their system.

Movement in the Plant
Triclopyr is absorbed through foliage and roots and is translocated systematically within the plant. Once inside, it moves upward through the xylem and downward through the phloem (ambimobile). This systemic movement allows triclopyr to affect not just the treated areas but also parts of the plant that are not directly sprayed. This attribute makes it effective for managing large, established plants, specifically through hack and squirt treatments (Fig. 4).

For the full article and conclusion sharing how Triclopyr is a valuable tool for managing invasive and woody plants view: The Summer of Triclopyr: Mounting evidence for off-target damage.

Subscribe and receive the newsletter: Purdue Landscape Report Newsletter.

Resources:
Find an Arborist video, Trees are Good-International Society of Arboriculture (ISA)
ID That Tree, Playlist, Purdue Extension – FNR YouTube Channel
Invasive Species Playlist, Playlist, Purdue Extension – FNR YouTube Channel
A Woodland Management Moment, Playlist, Purdue Extension – FNR YouTube Channel (Against Invasives, Garlic Mustard, Autumn Olive)
Woodland Stewardship for Landowners, Playlist, Purdue Extension – FNR YouTube Channel (Common Buckthorn, Japanese Barberry)
Report Invasive Species, Purdue Invasive Species
The GLEDN Phone App – Great Lakes Early Detection Network
Invasive Plants of the Eastern U.S.: An Introduction to the Problematic Non-Native Species, The Education Store, Purdue Extension’s resource center
EDDMaps – Early Detection and Distribution Mapping System
Episode 11 – Exploring the challenges of Invasive Species, Habitat University-Natural Resource University
What Are Invasive Species and Why Should I Care?, Purdue Extension-FNR Got Nature? Blog
Emerald Ash Borer Information Network, Purdue University and Partners
Aquatic Invasive Species, Illinois-Indiana Sea Grant (IISG)
Invasive plants: impact on environment and people, The Education Store, Purdue Extension’s resource center
Subscribe Purdue Extension-Forestry and Natural Resources YouTube Channel

Kyle Daniel, Commercial Landscape and Nursery Crops Extension Specialist
Purdue Horticulture & Landscape Architecture

---

Purdue Landscape Report: Most people these days have, at the very least, heard of Callery and Bradford pear trees and know something about the invasiveness of this ornamental street tree.  But I still get questions about what it is and why it’s so bad. So, I’d like to offer a little history of this infamous tree.  Where did it come from, why is it so popular, why is it such an awful tree to plant, and some suggestions for better species to plant in its place.

Pyrus calleryana, the Callery pear (Fig. 1), was originally introduced from Asia to the United States in 1908.  This was done in an attempt to breed pear trees that were resistant to fire blight, a bacterial disease that can spread rapidly causing leaves and branches to blacken as if burnt by fire, eventually resulting in death.  Along with its resistance, the Callery pear was tested as a rootstock for the edible European pear (Pyrus communis) and its vigor in growth.

Callery Pear grows to a height of 30 to 50 feet with a spread up to 30 feet wide.  Thick leaves grow alternately, are dark green, grow with sharp spurs along branches, and turn reddish-purple in the fall.  They are one of the first trees to bloom and begin to grow in the spring and one of the last to drop their leaves in the fall.  They produce a beautiful show of white flowers in the spring that have an unfortunate odor and an abundance of small fruits in the fall that are spread by birds and other wildlife.  In fact, invasive European Starlings are one of the primary species that feed on and spread the fruits and seeds.  Stems are smooth with light-colored lenticels while more mature stems are light to medium grey with fissures along the bark. Branching is usually upright in structure leading to poor branch unions that are weak and prone to failure.  They grow quickly and tolerate a wide variety of planting locations and conditions, which led to the widespread use as both street and ornamental trees in urban plantings.

The Bradford pear tree is a variety of Callery pear cultivated in the early 1950s as a sterile tree without sharp spurs.  Unfortunately, it cross-pollinated with other varieties leading to the rapid spread and out-competing of native species that we see in fields, along roadsides, and in forests today (Figs. 2 & 3).  As awareness of the environmental issues of Callery pear spreads, local and state governments are working on removing them from the landscape.  It is often joked that pruning these trees is extremely simple, involving a single cut at the base of the tree.

Due to the extensive use of these trees over the past 7 decades though, removals can lead to a large loss of existing canopy, especially with mature trees.  This loss is worth negating the ecological damage they cause and with patience can be replaced with more appropriate species.  Suggestions include serviceberry (Amelanchier laevis), flowering dogwood (Cornus florida), redbud (Cercis canadensis), and crabapple (Malus sylvestris).

For more information on invasive pear trees or on how to remove them see the links below.

To view this full article and other Purdue Landscape Report articles, please visit: Invasive Bradford/Callery Pear: Why it is so detrimental and what to plant instead.

Subscribe and receive the newsletter: Purdue Landscape Report.

Resources:
ID That Tree: Invasive Callery Pear, Purdue Extension – Forestry and Natural Resources (FNR) YouTube Channel
The Rise and Fall of the Ornamental Callery Pear Tree, Arboretum of Harvard University
Find an Arborist video, Trees are Good-International Society of Arboriculture (ISA)
ID That Tree, Playlist, Purdue Extension – FNR YouTube Channel (Invasive White Mulberry, Siberian Elm, Tree of Heaven)
Invasive Species Playlist, Playlist, Purdue Extension – FNR YouTube Channel (Asian Bush Honeysuckle, Burning Bush, Callery Pear, Multiflora rose)
A Woodland Management Moment, Playlist, Purdue Extension – FNR YouTube Channel (Against Invasives, Garlic Mustard, Autumn Olive)
Woodland Stewardship for Landowners, Playlist, Purdue Extension – FNR YouTube Channel (Common Buckthorn, Japanese Barberry)
Report Invasive Species, Purdue Invasive Species
The GLEDN Phone App – Great Lakes Early Detection Network
EDDMaps – Early Detection and Distribution Mapping System (Report Invasives)
How long do seeds of the invasive tree, Ailanthus altissima remain viable? (Invasive Tree of Heaven), USDA Forest Service
Indiana Department of Natural Resources: Invasive Species
Indiana Invasive Species Council
Cooperative Invasive Species Management Area (CISMA)
Aquatic Invasive Species, Illinois-Indiana Sea Grant (IISG)
Episode 11 – Exploring the challenges of Invasive Species, Habitat University-Natural Resource University
What are invasive species and why should I care?, Got Nature? Blog, Purdue Extension – FNR
Trees and Storms – The Education Store, Purdue Education’s resource center
Planting Your Tree, video, The Education Store
Tree Installation, The Education Store
Subscribe – Purdue Extension-FNR YouTube Channel

Ben McCallister, Urban Forestry Specialist
Purdue Forestry & Natural Resources

---

Governor Eric Holcomb has proclaimed February 25th to March 2nd as 2024 Invasive Species Awareness Week in Indiana.

This serves as an important reminder for Hoosiers to be aware and report potentially devastating invasives.

This proclamation states “invasive aquatic, riparian and terrestrial species influence the productivity, value and management of land and water resources in Indiana and the cost to prevent, monitor and control invasive species costs Indiana millions annually and after habitat destruction, invasive species are a great threat to biodiversity and threaten the survival of native plants and animals and interfere with ecosystem functions by changing processes like fire, nutrient flow and flooding”.

It continues with “invasive species impede industry, threaten agriculture, endanger human health and are becoming increasingly harder to control as a result of rapid global commercialization and human travel; and invasive species are as significant threat to almost half of the native species currently listed as federally endangered.”

As Invasive Species Awareness Week starts Sunday, February 25th, the Indiana Department of Natural Resources (IN DNR), Purdue Extension-Forestry and Natural Resources and the Indiana Invasive Species Council will answer any questions you may have.

For Questions:
Ask an Expert, Purdue Extension-Forestry and Natural Resources
Invasive Species – Indiana Department of Natural Resources (IDNR)
Indiana Invasive Species Council – Includes: IDNR, Purdue Department of Entomology and Professional Partners
Cooperative Invasive Species Management Area (CISMA)

Report and Learn More About Invasive Species –
Great Lakes Early Detection Network App (GLEDN) – The Center for Invasive Species & Ecosystem Health
EDDMaps – Early Detection and Distribution Mapping System
Purdue University Report Invasive Species, College of Agriculture

Check Out Our Invasive Species Videos –
Subscribe: Purdue Extension-Forestry and Natural Resources (FNR) YouTube Channel
Invasive Species YouTube Video Playlist includes:

• Asian Bush Honeysuckle
• Burning Bush
• Callery Pear
• Multiflora Rose
• Invasive Plants Threaten Our Forests Part 1: Invasive Plant Species Identification
• Invasive Plants Threaten Our Forests Part 2: Control and Management

More Purdue Extension-FNR YouTube Video Series –
Woodland Management Moment:

• Against Invasives
• Garlic Mustard
• Autumn Olive

Woodland Stewardship for Landowners:

• Common Buckthorn
• Japanese Barberry

ID That Tree:

• Invasive White Mulberry
• Invasive Siberian Elm
• Invasive Tree of Heaven

More Resources –
FNR Extension Publications, The Education Store:

• Invasive Plant Species: Tree of Heaven
• Invasive Plant Species: Oriental Bittersweet
• Invasive Plant Species: Wintercreeper
• Japanese Chaff Flower
• Kudzu in Indiana
• Mile-a-minute Vine

Purdue Landscape Report:

• Alternatives to Burning Bush for Fall Color
• Now is the Time to Identify Callery Pear

FNR Extension Got Nature? Blog:

• Woodland Invaders
• Invasive Species: the Good News and the Bad News

Don’t Miss These Resources:
Episode 11 – Exploring the challenges of Invasive Species, Habitat University-Natural Resource University
What Are Invasive Species and Why Should I Care?, Purdue Extension-FNR Got Nature? Blog
Emerald Ash Borer Information Network, Purdue University and Partners
Aquatic Invasive Species, Illinois-Indiana Sea Grant (IISG)
Invasive plants: impact on environment and people, The Education Store, Purdue Extension’s resource center

Purdue Extension-Forestry and Natural Resources

 

---