Got Nature? Blog

Sudden oak death, as the name suggests, is a disease that is capable of rapidly killing certain species of oaks.  It was first identified in California, in 1995. Two years earlier it was identified in Germany and the Netherlands, killing rhododendron. Because the pathogen originally infected and killed tanoaks, an undesirable, understory scrub tree, it generated little interest until other, more desirable oaks species began dying.  However, by this point, the disease was well established and eradication no longer an option, with millions of oak trees killed by the disease.  Currently, over 120 hosts in addition to oaks have been identified, and more continue to be added to this list.  What is most unusual about sudden oak death is the severity of disease symptoms coupled with the broad host range of the pathogen. This leads to difficulty in diagnosing and managing this disease.

What causes this disease?
The pathogen that causes SOD is Phytophthora ramorum (pronounced Fī-toff-thor-ă  ră-mor-ǔm).  This pathogen belongs to a group of organisms in the Kingdom Chromista, and has characteristics similar to fungi, plants and animals.  It spreads throughout the plant by hyphal threads (like fungi), produces spores (like fungi) that have flagella and swim through water (like animals), but its cell wall is made up of cellulose (like plants). When conditions dry up, Phytophthora can produce thick walled sexual spores called oospores, or asexual chlamydospores. Because P. ramorum is not a ‘true’ fungus, many fungicides labeled for control of other fungal diseases are not effective against it.

With such a broad range of plant hosts, it is important to stress that P. ramorum affects different species in different ways. Identification must be confirmed in the laboratory and cannot be identified on field symptoms alone. Many common landscape shrubs are also infected by other endemic Phytophthora species, and symptoms look similar. Boring insects and other root rots may be mistaken for this disease. For this reason, all Phytophthora infections should be screened by the Purdue Plant and Pest Diagnostic Laboratory.

What are the symptoms of SOD?
To understand this disease, it is important to recognize that there are two categories of hosts: bark canker hosts and foliar hosts. Further complicating this is the fact that oaks are divided into three subgroups, and only the red oak group are susceptible to this pathogen. Of our 17 oak species in Indiana, half are potentially, or known to be susceptible, and include black, blackjack, cherrybark, Northern pin, pin, red, scarlet, and Shumard oaks. Diagnostic symptoms of infected red oaks include oozing sap and red-brown cankers that often leading to death.

Our concern right now is on ‘the other’ hosts. Despite its name, sudden oak death primarily spreads through foliar hosts that are sold throughout the United States. Foliar hosts include rhododendrons, azalea, viburnum, lilac, and periwinkle (Vinca minor).

These hosts (and many others) are infected via the leaves and small branches. These infections rarely cause death, and can be mistaken for sunscald, twig canker, and dieback caused by other pathogens, including native Phytophthora species. Although symptoms from these infections are not severe, and are rarely fatal, the infections produce enormous numbers of spores that can infect neighboring, susceptible oaks—and other plant species. For this reason, we are asking people to examine any rhododendrons (or other co-mingled hosts like azalea, viburnum and lilac) purchased this spring from Walmart and Rural King, while the disease may still be controlled and the pathogen contained. Although this disease doesn’t look like much on rhododendron or lilac, its ability to spread to oaks and kill them is what makes it so devastating. These shrubs play a key role in the spread of P. ramorum, acting as a breeding ground for spores (inoculum) that can spread through water, wind-driven rain, plant material, or human activity. Oaks are considered terminal hosts, since the pathogen does not readily spread from intact bark cankers; they become infected only when exposed to spores produced on the leaves and twigs of neighboring plants.

For full article and photos view: Purdue Landscape Report

Other resources:
Sudden Oak Death, California Oak Mortality Task Force
Sudden Oak Death, Indiana Department of Natural Resources
White Oak, The Education Store, Purdue Extension resource center
Planting Forest Trees and Shrubs in Indiana, The Education Store
Successful Oak and Hickory Regeneration, The Hardwood Ecosystem Experiment: 2006-2016, The Education Store
Find a Certified Arborist, International Society of Arboriculture

Janna Beckerman, Professor
Purdue Botany and Plant Pathology

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Question: I have noticed that a lot of very mature (> 80 ft) sycamore trees look ill. They don’t seem to have as many leaves, or as large as they usually get and some have already turned brown and died. There are at least 2 in my 5 acres of woods and have noticed the same with other sycamores while driving from Mooresville to Indianapolis. Is there a certain blight/canker/pest that is damaging sycamores this year?

Answer: I have also noticed that many sycamores appear relatively bare and may have brown or wilted leaves on the stems and littering the ground around the trees. The culprit is sycamore anthracnose, a fungal disease that causes damage and death of leaves as well as stem cankers. Sycamore anthracnose symptoms can be severe when we have cool, moist spring weather at the time of bud-break and leaf emergence , but healthy trees generally recover and put on new leaf area once the environmental conditions that favor the disease change to the warmer, drier conditions of late spring and summer.

Normally, the best management practices for sycamore anthracnose are patience and maintaining good tree health. The disease cycle is dependent on cool, moist spring weather, so it will run its course by late spring or summer when the average temperatures rise. Trees that are repeatedly defoliated could be reduced in vigor and be more susceptible to other problems, so steps to promote good tree health can be used as a preventative measure.

Resources:
Fertilizing Woody Plants – The Education Store, Purdue Extension Resource Center
Diseases of Landscape Plants (leaf diseases) – The Education Store
Sycamore – The Education Store
Hardwood Lumber and Veneer Series – The Education Store
Anthracnose of Shade Trees – Purdue Plant and Pest Diagnostic Laboratory
Purdue Plant Doctor App- Purdue Extension

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

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The Invasive Terrestrial Plant Rule was signed by Governor Holcomb and published on March 18, 2019. the rule goes into effect 30 days after publishing, so it will be effective in April.

The Rule States that a person must not:

• sell, offer or grow for sale, gift, barter, exchange, or distribute a species;
• transport or transfer a species;
• introduce a species

with respect to the 44 invasive plant species (see full list in the Landscape Report).

Note: Selling, offering, distributing and transporting doesn’t go into effect until April of 2020, so nurseries will have some time to sell down their stock. This is an important component of the rule to minimize economic loss to nurseries that grow and/or sell the few commercially available species that are on the list. Currently there is no mandate to eradicate existing plantings in nurseries, landscapes, or forested areas

To learn more about what an invasive species is, what damage they do, what Indiana is doing, and more please read the Landscape Report, Terrestrial Invasive Species Rule Signed by Indiana Governor.

Resources
Mile-a-Minute Invasive Vine Found Indiana, Got Nature? Blog
Invasive plants: impact on environment and people, Purdue Extension The Education Store
Invasive Plant Species in Hardwood Tree Plantations, The Education Store
Invasive Plant Species: Callery Pear, Purdue Extension The Education Store
Invasive Plant Species: Wintercreeper, Purdue Extension The Education Store
Invasive Plant Species Oriental Bittersweet, Purdue Extension The Education Store
Report Invasive Species, Purdue Invasive Species
The GLEDN Phone App – Great Lakes Early Detection Network
EDDMaps – Early Detection and Distribution Mapping System (Report Invasives)
Cooperative Invasive Species Management Area (CISMA)
Indiana Department of Natural Resources: Invasive Species
Indiana Invasive Species Council

Indiana Department of Natural Resources (IDNR)

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Purdue University’s Tick INsiders program is looking for Indiana high school students and other Indiana residents willing to roll down their sleeves to get involved in a citizen science project.

Cate Hill, a Purdue professor of entomology, leads this effort to analyze the bacteria and viruses in Indiana’s ticks to build an understanding of what they are carrying and how that might impact human health. To do that, she needs volunteers to collect ticks from all over the state.

This year the Tick INsiders program will provide training for up to 50 students. Citizen scientists are also now welcome to collect and send ticks to Hill’s lab.

“It’s really important work. The Centers for Disease Control and Prevention reports that human cases of tick-borne diseases doubled from 2004 to 2016. If we’re going to get a handle on that and develop strategies for reducing tick bites and treating patients, we need to know where our ticks are and what our ticks are carrying around inside them,” Hill said. “That means we need a lot of ticks, and we need help collecting them.”

Three species of ticks – the blacklegged or deer tick, the lone star tick and the American dog tick – are found in Indiana. These ticks can transmit multiple pathogens, nine of which are known to cause human illnesses, though not all have been identified in Indiana. The Indiana State Department of Health reports more than 100 cases of Lyme disease each year and dozens of cases of Ehrlichiosis, anaplasmosis and Rocky Mountain spotted fever.

Research suggests that ticks can carry a cocktail of microbes – bacteria and viruses – that can sicken bite victims and may work in concert to affect the severity of an illness and human immune response.

“Not all tick bites are the same. We don’t know what is passed from a tick to a human each time someone is bitten, which means that health care professionals may need to consider multiple tick-borne pathogens in a person who has been bitten by a tick,” Hill said. “This program improves our knowledge so that we can improve our outcomes.”

Indiana residents interested in participating can collect ticks and send them to Hill’s lab for analysis. Videos on safe and proper collection techniques, as well as how to send ticks will be at Tick INsiders.

For full article, see Purdue Agriculture News.

Resources

Ticks 101: A Quick Start Guide to Indiana Tick Vectors, The Education Store – Extension Resource
The Biology and Medical Importance of Ticks in Indiana, The Education Store
Mosquitoes, Purdue Extension Entomology
One Small Bite: One Large Problem, Got Nature?, Purdue Extension-Forestry and Natural Resources
Mosquitoes and ticks – little pests carry big risks, Got Nature?

Catherine A Hill, Professor of Entomology/Vector Biology
Purdue University Department of Entomology

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Having raccoon, groundhog, or other bothersome wildlife problems? Thinking about setting traps to catch these animals? There is much to consider when using traps. Take a look at the latest publication for best results.

Wildlife specialists Brian MacGowan and Rick Shadel have collaborated to bring you this new publication: Considerations for Trapping Nuisance Wildlife with Box Traps.

Homeowners commonly set traps to capture and remove wildlife from their home or yard. Setting a box trap improperly can decrease their effectiveness and even lead to safety risks to both people and wildlife. The purpose of this publication is to 1) outline the legal and ethical factors homeowners should consider before setting a trap, 2) review the basic procedure for effectively trapping wildlife, and 3) help you to determine the fate of the captured animal.

If you have a serious, dangerous, or a nuisance wildlife issue, you may want to consider hiring a professional. Consider reading this publication before deciding whether or not you need to hire a professional: Selecting a Nuisance Wildlife Control Professional.

Resources
Preventing Wildlife Damage – Do You Need a Permit? – The Education Store, Purdue Extension resource center
Selecting a Nuisance Wildlife Control Professional, The Education Store
How to Construct a Scent Station, The Education Store
Question: How do I properly relocate raccoons from my attic?, Got Nature? Blog, Purdue Extension FNR
Nuisance Wildlife – Indiana Department of Natural Resources

Brian MacGowan, Wildlife Extensions Specialist
Purdue Forestry and Natural Resources

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Kristol from Tippecanoe County, IN, sent in question to the Purdue Extension-Forestry and Natural Resources experts (Ask an Expert) asking what resources are available to help with landscaping for a front yard and sidewalk area that accumulates water after a hard rain. She also asked for resources to improve drainage.

Purdue Extension has several articles and resources to help with this type of situation.

The resources in our Rainscaping and Master Gardeners Program shares several neat options:
Rain Gardens Go with the Flow, Indiana Yard and Garden, Purdue Horticulture
Rainscaping Program
Master Gardeners Program

Don’t miss the publications located in the Purdue Extension resource center, The Education Store, relating to the topic:
Tree Installation: Process and Practices
Planting Forest Trees and Shrubs in Indiana
Climate Change: How will you manage stormwater runoff?

For Midwest Landscapes, have a look at the Purdue Landscape Report:
Purdue Landscape Report

Check out upcoming workshops available for land and woodland owners, to talk with an expert:
Purdue Extension-Forestry and Natural Resources Calendar

Check out our Got Nature? posts as well, as this is always a great resource for new information:
Got Nature?, Forestry and Natural Resources-Purdue Extension

These resources give you lots of options that match what your looking for along with experts in the field to contact if needed.

We always appreciate the questions coming in, so keep them coming. Our experts will respond quickly and give you the guidance you need for your next steps.

Diana Evans, Extension Information Coordinator
Purdue Forestry and Natural Resources

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This looks to be shaping up as a tough winter for us and our trees. Lots of snow and ice are predicted for the Hoosier state and this can be a challenge for our trees and shrubs.

After a heavy snowfall, protect your trees and property with these simple tips:

Do not shake limbs to try to remove snow or ice.
When you find your trees are bending or drooping as a result of ice or snow accumulation, your first instinct is probably to shake the branches or knock the weight off with a broom or something similar. This may cause worse damage or actually cause the branch to snap off. Stop right there! Healthy tree branches are flexible, so knocking off the accumulation of snow or ice accretion may cause them to “snap” back, potentially damaging their food and water transport system. The results of the damage may not be evident until next spring.

Trees that tend to suffer the worst damage as a result of snow and ice are upright evergreens, like arborvitae and juniper, and clump trees, like birch. And, when it comes to ice, age does not make a tree stronger; younger trees are better at actually overcoming damage in ice storms.

Hire a Professional.

Safely remove broken limbs.
Broken and hanging branches can be a threat to people and property. If a limb breaks off from the weight of ice or snow and remains in the tree canopy, have it removed and the remaining stub properly pruned to the branch collar as soon as weather allows. The tree will recover better when properly pruned. For undamaged limbs bending under the weight of ice or snow, don’t prune as a means of correcting the situation. Be patient. It takes time for wood fibers in the limbs to return to its natural position.

Always be mindful of walking or parking under branches loaded down by snow or ice as they may snap and fall, causing injury or damage. If a limb breaks and becomes entangled in power lines, notify your utility company immediately. Never approach a downed power line or a branch touching a utility line.

If there is substantial damage to your tree, have an arborist examine damaged branches and limbs for signs of weakness and injury for reparations. It is best to always hire an ISA Certified Arborist. To find an arborist in your area, visit the website, www.treesaregood.org

How can you help prevent ice damage to trees? Proper pruning is one way. Particularly important is the removal of poor branch attachments and weak branch structure in the tree, prior to winter. For more information on pruning, download the publication, Tree Pruning Essentials.

Full article published in the Purdue Landscape Report.

Resources
Avoid Deadly Risk of Dying Ash Trees with Timely Tree Removal, Got Nature? Purdue Extension-FNR
New Hope for Fighting Ash Borer, Got Nature? Purdue Extension-FNR
Invasive Pest Species: Tools for Staging and Managing EAB in the Urban Forest, Got Nature?
Emerald Ash Borer, Purdue Extension-Entomology
Emerald Ash Borer Tools & Resources – Purdue Extension Entomology
Corrective Pruning for Deciduous Trees, The Education Store, Extension Publications

Lindsey Purcell, Chapter Executive Director
Indiana Arborist Association

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Groundhogs are good at many things, said Brian MacGowan, Purdue University Extension wildlife specialist and Forestry and Natural Resources Extension coordinator, but predicting the weather definitely isn’t one of them.

The lore surrounding Groundhog Day originated in Germany where people used the reactions of badgers and hedgehogs to gauge weather patterns. When the tradition eventually migrated to America, Jarred Brooke, Extension wildlife specialist, said hedgehogs, which can be found throughout the United States, became the mammalian forecaster of choice.

“They’re crafty little critters,” McGowan explains, “which is why they’re found in so many different places. They’re habitat generalists and can live in open woodlands, grasslands, what have you.”

While MacGowan and Brooke agreed groundhogs don’t have a great track-record of weather prediction, other facts make groundhogs one of the more interesting members of the squirrel-family.

For full article see: Groundhogs can’t predict the weather but they do poop underground.

Resources:
Selecting a Nuisance Wildlife Control Professional – The Education Store, Purdue Extension Resource Center
Preventing Wildlife Damage – Do You Need a Permit? – The Education Store
The Basics of Managing Wildlife on Agricultural Lands – The Education Store
Nuisance Wildlife – Indiana Department of Natural Resources
Dealing with nuisance geese this spring – Got Nature?
Animal Damage Management: Woodchucks, The Education Store

Brian MacGowan, Wildlife Extension Specialist
Purdue University, Forestry and Natural Resources

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How do I remedy poor branching? Is my tree at risk of splitting, and how can pruning prevent that? Corrective pruning has many implications for tree structure, health, and longevity. Developing a strong, central branch structure in a deciduous tree is critical for preventing structural failure caused by storms, wind, and ice. This 8-page publication explains the problems resulting from a co-dominant stem structure and addresses pruning strategies for correcting poor structure.

To view this full publication please go to Corrective Pruning for Deciduous Trees located in The Education Store, Purdue Extension’s resource center.

Resources
Preparations to Prevent Southwest Tree Injury, Got Nature? Blog
When do you stake a tree?, Got Nature? Blog
Top 5 List for Tree Selection and Planting, Got Nature? Blog
Tree Selection for the “Un-natural” Environment, The Education Store, Purdue Extension
Tree Support Systems, The Education Store, Purdue Extension
Tree Installation: Process and Practices, The Education Store, Purdue Extension
Planting Your Tree Part 1: Choosing Your Tree, video, The Education Store, Purdue Extension

Lindsey Purcell, Urban Forestry Specialist
Purdue Forestry and Natural Resources

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The latest Wildlife Bulletin, provided by the Indiana Department of Natural Resources-Division of Fish and Wildlife, has all the Indiana hunting information you need to know along with upcoming events and resources. Topics include: Get your deer licenses now; Deer hunting checklist; Deer processing videos on YouTube; Hunting seasons dates; Four options to check in game; Sandhill crane migration at Jasper-Pulaski; and much more.

The Wild Bulletin is a free email newsletter offering information about Indiana’s fish and wildlife resources and recreation opportunities. Subjects covered include profiles, information about hunting and fishing season dates, regulation updates, wildlife and fisheries research status reports, tips on wildlife watching and reminders about important dates for Hoosier outdoor enthusiasts.

To subscribe to this free e-newsletter visit Wild Bulletin, Indiana Department of Natural Resources.

Other resources:
State Parks, Indiana Department of Natural Resources (IN DNR)
Outdoor Indiana, Indiana Department of Natural Resources (IN DNR)

Indiana Department of Natural Resources

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