Got Nature? Blog

Purdue Landscape Report: We have received a few elm tree samples this year with a disease we do not often see, but which is relatively common: black spot of elm. This disease, also called elm anthracnose, is caused by the fungus Stegophora ulmea and can affect most species of elm with American elm varieties being more susceptible.

The fungus becomes active in the spring at temperatures of 45 deg F or above. It can release spores that will infect newly unfolding leaves leading to chlorotic leaf spots or blotches on the upper leaf surface. Black fungal fruiting bodies will develop within the affected tissue, making it seem like the leaves have been dotted with tar. These fungal structures are raised and will give the leaf a bumpy texture. As more spots develop and coalesce, they will create white areas of dead tissue that can eventually turn brown.

The black fungal stromata can produce asexual spores (conidia) which can cause new infections during the growing season. Conidia are produced in a mucilage which becomes loose in humid conditions and can be spread by water splash (rain or irrigation). While leaf infections are the most commonly observed symptom, Stegophora can also infect leaf petioles and twigs. Premature leaf drop due to severe leaf spotting can occur, but significant defoliation may also develop when petioles are infected. Stem infections can lead to shoot blighting and small limb dieback.

Black spot is generally worse when the weather is cool and moist over an extended period of time. The fungus can reinfect the tree throughout the season during rainy. When the summer turns hot and dry, disease development will slow down and trees with twig blighting may show some recovery by pushing out new growth from dormant buds below affected shoots. Please note that twig blighting may look similar to flagging branches associated with Dutch elm disease (DED), so we recommend pruning off the branch and looking for internal vascular streaking to rule out DED.

Fungicides are not normally recommended to manage this disease for mature trees in landscapes since it is impractical to get full coverage of the foliage and damage is not usually severe. However, preventative applications may be warranted in nursery settings when the disease is severe to protect new growth and slow down disease spread until drier weather occurs, especially where overhead irrigation is used. Raking up leaf litter and pruning out infected stems will remove inoculum for the following season and help prevent existing infections from spreading.

Click here for more information on Dutch elm disease and view this original article here: A New Threat to Elms in North America

Subscribe and receive the newsletter: Purdue Landscape Report Newsletter.

Resources:
Intro to Trees of Indiana: American Elm, Got Nature? Blog, Purdue Extension – FNR
Intro to Trees of Indiana: Slippery Elm, Got Nature? Blog, Purdue Extension – FNR
ID That Tree, Playlist, Red Elm, Siberian Elm, Winged Elm, Purdue Extension – Forestry and Natural Resources (FNR) YouTube Channel
Invasive Species Playlist, Playlist, 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
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
Native Trees of the Midwest, The Education Store
Investing in Indiana Woodlands, The Education Store
Forest Improvement Handbook, The Education Store

John Bonkowski, Lead Extension Administrator
Purdue Department of Botany and Plant Pathology

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“Right now, we’re seeing a mix of fall coming in and shifting temperatures, which is causing trees to respond. This back-and-forth hot weather is creating some color changes related to drought and stress. This can be expressed as brown color where leaves are starting to wilt and look a little crunchy from exposure to heat and drought stress,” McCallister explains.

Devyn Raver, Media Relations and Content Development Specialist
Purdue Forestry & Natural Resources

Ben McCallister, Urban Forestry Specialist
Purdue Forestry & Natural Resources

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Question: We have a large 60+ foot mulberry tree in our backyard that is located by our pond. This is the first year I have seen these dark streaks on the bark of the tree. Should I have concerns?

Answer: From the photos, it looks like wet wood/slime flux is affecting your tree. It is a bacterial infection on trees and in most cases is not a serious issue, but unfortunately, there is nothing to be done about it. Many years ago they used to drill holes to try and allow gases and liquids drain from an area with the slime flux but through research and experience this practice is not recommended.

The Purdue Landscape Report titled Slime Flux of Trees shares more about this disease:
Slime flux (also known as wet wood) is a dark, foul-smelling and unsightly seepage of sap from tree trunks. The disease is not usually a serious problem but the appearance can be alarming. Slime flux is caused by common surface-inhabiting bacteria or yeast fungi that enter the trunk through wounds associated with improper pruning, stem breakage, injections, cracks from freeze injury or weak limb crotches. The bacteria and yeast may live on sap nutrients within injured trees for many years without any outward evidence.

Symptoms
The main symptom is the appearance of the dark sap oozing on the trunk exterior which happens when gasses produced by growth of the bacteria and yeast cause the internal pressure of the sap to become high enough to force the sap out through cracks in the bark. The dark streaks usually turn light gray or white upon drying. Oozing sap may be frothy and white at the point of exit. Airborne bacteria, yeasts, and fungi often colonize the wet oozing material, which ferments and releases a foul odor. Slime flux may delay wound healing (callus formation).

For prevention and other resources view: Slime Flux of Trees.

Resources
Purdue Landscape Report
Find an Arborist video, Trees are Good-International Society of Arboriculture (ISA)
Tree Pruning Essentials, Publication & Video, The Education Store, Purdue Extension resource center
Tree Pruning: What Do Trees Think?, The Education Store
Tree Installation Process and Practices, The Education Store
Tree Pruning for the Landscape, Webinar, Purdue Extension – Forestry and Natural Resources YouTube channel
Tree Wounds and Healing
Why Is My Tree Dying?, The Education Store
Tree Risk Management, The Education Store
What Are Invasive Species and Why Should I Care?, Got Nature? Blog Post, Purdue Extension – FNR
Purdue Plant & Pest Diagnostic Lab (PPDL)
Subscribe – Purdue Extension-FNR YouTube Channel

Ben McCallister, Urban Forestry Specialist
Purdue Forestry & Natural Resources

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Lenny Farlee, sustaining hardwood Extension specialist for Purdue’s Department of Forestry and Natural Resources (FNR), has been named a 2024 Fellow of the Society of American Foresters (SAF). The SAF Fellow Award, one of the highest honors bestowed on an SAF member by their peers, recognizes long-standing service to forestry at the local, state, regional and national levels.

Farlee was honored with the award during the 2024 SAF National Convention, which took place in Loveland, Colorado from Sept. 17-20.

“Being named a Fellow of the Society of American Foresters is particularly meaningful to me since it originates from a nomination by my peers at the state level,” Farlee said. “I am very grateful that my colleagues in forestry here in Indiana considered my service worthy of recognition, and I owe much of the credit to them for their support of me through my career. It has been my privilege to serve the people and the profession as an Extension forester here at Purdue.”

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Morning AgClips — Nestled within the cool, flowing waters of Indiana’s Blue River, the elusive hellbender thrives under big, flat rocks, seeking refuge from predators and finding the perfect conditions to lay their eggs. But in recent years, they have become increasingly difficult to find.

Morning AgClips interviews Purdue hellbender team for details regarding Farmers Helping Hellbenders Project, aimed at restoring Indiana’s endangered hellbender salamander population by improving water quality in the Blue River-Sinking watershed. Learn more about this initiative by hearing directly from the people involved, with the two overarching goals being about improving hellbender habitat and also enhancing local farming operations. Particularly, the project engages farmers in adopting sustainable practices as well, while strengthening conservation efforts for hellbenders.

Hellbenders used to have a much larger range, occurring in most of southeast Indiana’s tributaries to the Ohio River and in the Wabash River. Sadly, its population has dropped drastically due to modification of stream habitats including the accumulation of sediment, agricultural and industrial pollution, warming waters and the channelization of streams and rivers. Because of their decline, these endangered ancient amphibians, with their large, unique flat bodies, have become the focus of an ambitious conservation effort led by Purdue University.

“The significance of the hellbender and its conservation extends beyond the species itself,” Purdue Extension Wildlife Specialist, Nick Burgmeier explains. “Hellbenders are an indicator species; their presence reflects the health of the water quality. Historically common and a top predator in streams, their decline has ecological repercussions, particularly on crayfish populations, which can disrupt food webs.”

Read more on the Morning AgClips website at Rebuilding Indiana’s Hellbender Habitat.

Resources:
Farmers Helping Hellbenders RCPP Program Accepting Applications, Purdue Forestry and Natural Resources News
USDA Awards Farmers Helping Hellbenders Project in Funding, Purdue Extension – Forestry and Natural Resources (FNR) Got Nature? Blog
Improving Water Quality by Protecting Sinkholes on Your Property, Purdue Extension – FNR YouTube Channel
Improving Water Quality Around Your Farm video, Purdue Extension – FNR YouTube Channel
Adaptations for Aquatic Amphibians, The Education Store, Purdue Extension’s resource center
Hellbenders Rock! Nature of Teaching Lesson Plan, The Education Store
Nature of Teaching – Hellbenders Rock Sneak Peek video, Purdue Extension – FNR YouTube Channel
Nature of Teaching – Hellbenders Rock webinar video, Purdue Extension – FNR YouTube Channel
Learn about hellbenders and take a tour of Purdue’s hellbender rearing facility video, Purdue Extension – FNR YouTube Channel
Learn about the hellbender work at Mesker Park Zoo video, Purdue FNR Facebook
Learn about hellbender work at The Wilds video, Purdue FNR Facebook
Dr. Rod Williams’ 2017 TEDx Talk Help the Hellbenders video, Purdue Extension – FNR YouTube Channel
A Moment in the Wild – Hellbender Hides video, Purdue Extension – FNR YouTube Channel
A Moment in the Wild – Hellbender Release video , Purdue Extension – FNR YouTube Channel

Morning AgClips

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Purdue Landscape Report: August was National Check Your Tree Month, but this is something that every tree owner/manager should be doing year-round.  As the last hot days of summer are finishing up and we look forward to cooler fall days, we can look to our trees for different signs of trouble.

Most people tend to look up at the canopy before anything else in trees. Check leaves for dieback, discoloration, stickiness or signs of chewing. Check branches and the main stem for damage like splits and breaks, peeling bark, tunneling patterns under the bark, oozing wet spots, or sawdust around the tree. These could be signs of issues in the root system, pathogens like bacteria or fungal organisms, insect problems, or structural damage.

This is not an exhaustive list and if you notice these or anything else that seems off, it could be time for a deeper dive into what might be wrong. If you know the species of your tree the Purdue Plant Doctor is a great tool to narrow down a diagnosis. You can also contact your local Extension office or an ISA Certified Arborist.

On a more positive side, you don’t have to be on the lookout for damage, decline, or signs of pathogens and pests. It is also a matter of enjoying the trees in your landscape. Take some time out of your day to sit in the shade especially as we transition from hot summer temperatures into the cooling of autumn. Revel in the color changes as chlorophyll production slows revealing the carotenoids (that give us yellows, oranges, and browns) and anthocyanin (that produces reds and purples). In winter, not only can you better see damage in the canopy hidden by leaves in the growing seasons, but also the structure and architecture of the canopies in different tree species and the differences in bark textures. And in Spring, new growth of leaves and flowers shows us Winter is nearing its end, bringing warmer days.

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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

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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

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MyDNR, Indiana’s Outdoor Newsletter: As a result of Indiana’s positive detection of chronic wasting disease (CWD) in LaGrange County in April, Indiana DNR has restricted moving deer from any CWD Positive Area for rehabilitation purposes.

With the change, an individual who finds an orphaned, sick, or injured deer in a CWD Positive Area may only surrender the deer to a DNR-permitted wild animal rehabilitator that is located within a CWD Positive Area. This restriction is to help minimize the spread of CWD to new parts of the state, as deer can carry this disease without appearing sick.

Currently, there is one CWD Positive Area in Indiana. It includes LaGrange, Steuben, Noble, and DeKalb counties. While no CWD positive deer have been documented in Steuben, Noble, or DeKalb counties, those counties are considered part of the CWD Positive Area because of their proximity to where the state’s first CWD-positive deer was found in LaGrange County.

During their first few weeks of life, fawns often hide by themselves and stay motionless to avoid predators while the mother is looking for food. If you find a fawn alone, you can help it by letting it be, giving it space, and leaving the area. Its mother is likely nearby.

For more information visit DNR: Chronic Wasting Disease (CWD).

To subscribe to the newsletter visit MyDNR Email Newsletter.

Resources:
Chronic Wasting Disease, USDA Animal and Plant Health Inspection Service (APHIS)
Bovine Tuberculosis in Wild White-tailed Deer, The Education Store, Purdue Extension resource center
Hunting & Trapping, Indiana Department of Natural Resources (DNR)
Designing Hardwood Tree Plantings for Wildlife , The Education Store
Wildlife Habitat Hint: Trail Camera Tips and Tricks, Got Nature? Blog
How to Score Your White-tailed Deer, video, The Education Store
White-Tailed Deer Post Harvest Collection, video, The Education Store
Age Determination in White-tailed Deer, video, The Education Store
How to Build a Plastic Mesh Deer Exclusion Fence, The Education Store
Ask the Expert: Hardwood Ecosystem Experiment – Birds and Salamander Research, Purdue Extension – FNR
A Template for Your Wildlife Habitat Management Plan, The Education Store
Managing Your Woods for White-Tailed Deer, The Education Store
Deer Impact Toolbox, Got Nature? blog, Purdue Extension-Forestry and Natural Resources (FNR)

Indiana Department of Natural Resources

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The Indiana Natural Resources Teacher Institute (NRTI) is an annual multi-day conservation education workshop and tour of forest management, forest industry and forestry research in Indiana. The purpose of the institute is to provide an introduction to the impact sustainable forestry has on our state’s environment, economy, and quality of life, and to equip teachers to apply that knowledge in the classroom.

The 5-day workshop advances effective teaching and learning about Indiana’s forest resources and their management. Participants will learn how to approach the teaching of STEM (science, technology, engineering and math) concepts and principles from a natural resource perspective through exposure to professionals, researchers, and industry leaders and hands-on experiences in the field. Participants develop a curriculum project to be implemented with their students, bringing natural resource science and management topics and activities into the classroom.

Several partners and many sponsors and supporters facilitate this program. The Indiana DNR Division of Forestry Project Learning Tree Coordinator, Lexi Eiler, serves as the lead on this project, and the Division provides housing for the participants at the Morgan Monroe State Forest Training Center. Donna Rogler, the originator of the Indiana NRTI, Lenny Farlee, Purdue Forestry and Natural Resources Extension Forester, and Mary Cutler, Tippecanoe County Parks and Recreation Naturalist, serve as Instructors/facilitators with Lexi for the week of activities and tours. Each of these individuals is also an alumnus of Purdue Forestry and Natural Resources!

Presenters from several agencies, organizations, and companies assist with field tours and presentations, including a tour and activities on the Hardwood Ecosystem Experiment site at Morgan Monroe State Forest. The connection with this long-term, large-scale research project provides a unique STEM application teachers can take back to their classrooms.

The NRTI program can accommodate up to 16 teachers, with emphasis on primary educators, but welcoming to educators from all ages and backgrounds. Many past participants have called this week the best professional development training they have attended. Some comments from our most recent class in June of 2024:

“It was amazing. I am grateful for the activities and all the fantastic materials provided.”

“I learned so much about forestry and forest ecology. I can’t wait to share my lesson with the students.”

“Loved my time at the Indiana Natural Resources Teacher Institute! I learned so much and can’t wait to share and do activities at school this year.”

Educators interested in the workshop can visit this DNR website to find out more about schedules and applications – https://www.in.gov/dnr/forestry/programs/education/

Resources:
Purdue Forestry and Natural Resources Facebook Page
Project Learning Tree
Indiana Department of Natural Resources Division of Forestry
The Nature of Teaching, Purdue Department of Forestry and Natural Resources
The Nature of Teaching: Trees of the Midwest, The Education Store
The Nature of Teaching: Adaptations for Aquatic Amphibians, The Education Store
Trees of the Midwest Webinar, Nature of Teaching YouTube channel
Indiana Forestry Educational Foundation, Indiana Forestry & Woodland Owners Association
Forest/Timber, Playlist, Purdue Extension – Forestry and Natural Resources YouTube Channel
Natural Resources Teacher Institute Takes Forestry to the Classroom, Purdue FNR News
Purdue Extension

Lexi Eiler , Coordinator
Indiana Project Learning Tree

Lenny Farlee, Sustaining Hardwood Extension Specialist
Purdue University Department of Forestry and Natural Resources

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