Purdue University - Extension - Forestry and Natural Resources
On May 5th, we held a Facebook LIVE: Ask an Expert with several FNR specialists and one of the questions that came in is a question I receive often.
One of the many benefits of interacting with farmers and land managers is I learn about the problems you face. A question came in around the 17:30 minute mark of how to deal with vole damage problems in their 3- to 5-acre pumpkin patch. I didn’t have an answer regarding registered pesticides (including taste repellents and toxicants) that are labeled for voles in pumpkins. Doing a broad search on the internet is helpful but it is hard to figure out what you can use in your state. Pesticides are often labeled for use in one state but not others. Luckily, anyone can search for registered pesticides online at on the National Pesticide Information Retrieval System. Most states, including Indiana, are included. You can search by EPA registration number, product name, company name, or active ingredient. A particular search can still yield many choices but this is a helpful way of finding out what is available. Each product has a link to the EPA website that includes product labels.
Since our program last week, I did some checking and found a product registered in Indiana labeled for voles in pumpkins as well as many other crops. Millers Hot Sauce is a taste repellent with an active ingredient of capsaicin (2.5% by weight), which is an irritant to animals, but one some people enjoy in hot peppers. Per label instructions adding an antitranspirant film former or a sticker may prolong the effectiveness of the product. Mix the product and additives with water according to label instructions. For heavy damage, start treatment after first true leaves appear and continue treatment every 7 days. If applying to transplants, start application one week after transplanting and continue every 7 days.
Always read the label completely before applying any pesticide. The efficacy of any repellent depends on a number of factors including animal population size and density, available food, and availability of cover. With voles, the year can be key because their populations tend to cycle. Combining other methods with repellents can often increase success. For example, soil cultivation within plant rows and in adjacent habitat can help reduce the habitat quality for voles. Cultivation can also directly kill some voles. There are of course tradeoffs and every situation is unique. Soil cultivation would not be an option in some cases (e.g., adjacent to water, steep slopes). I was unable to find a toxicant registered for voles in pumpkins. But depending on what the land cover is adjacent to the pumpkin patches, some of these may be appropriate in those areas.
With face-to-face Extension programs on hold for the foreseeable future, look for more live Q&A sessions and other programs on Facebook (PurdueFNR) or Twitter (@PurdueFNR).
Resources
National Pesticide Information Retrieval System
Midwest Fruit Pest Management Guide, The Education Store, Purdue Extension resource center
Hops Production in Indiana: Integrated Pest Management Guide for Hops in Indiana, The Education Store
Turfgrass Insects: Managing Black Cutworms in Turfgrass, The Education Store
Applied Research in Field Crop Pathology for Indiana – 2019, The Education Store
Managing Alfalfa Autotoxicity, The Education Store
Brian MacGowan, Wildlife Extensions Specialist
Purdue Forestry and Natural Resources
Resourceful Animal Relationships is one unit in a series available from The Nature of Teaching – the place to go for teaching resources that focus on wildlife, food waste, health and wellness. In this series teachers can find free lesson plans, printables, posters, a photo library, information on upcoming workshops and more.
This lesson will teach third- through fifth-grade students about different kinds of organism interactions and how those interactions affect the ways in which organisms gain or lose resources. Students will learn how to describe the differences between mutualism, parasitism,
and competition along with how to explain the different effects that relationships have on an organism and their resources.
It meets several grade-appropriate Next Generation Science Standards, English/Language Arts Standards, and Math Standards. This 19-page pdf is written by Dr. Rod Williams.
For more resources, please check the Education Store.
Resources
Benefits of Connecting with Nature, The Education Store, Purdue Extension resource center
The Nature of Teaching: Ecotoxicology and Environmental Health, The Education Store
The Nature of Teaching: Disease Ecology, The Education Store
The Nature of Teaching: Adaptations for Aquatic Amphibians, The Education Store
Adaptations for Aquatic Amphibians Activity 2: Water Quality Sneak Peak, Video, Purdue Extension YouTube channel
Rod Williams, Professor of Wildlife Science
Purdue University Department of Forestry and Natural Resources
With large amounts of white-tailed deer populating the area around forest land, getting your hardwood seedlings established can be difficult.
Purdue Extension forester Lenny Farlee, sustainable hardwood extension specialist, offers some tips on how to protect newly planted seedlings from browsing deer using plastic mesh fencing to exclude the animals from the area. He also mentions tree tubes and electrified fencing as potential options. Learn more in the video below.
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
USDA Cost Assistance Programs for Conservation Practices
How to Build a Plastic Mesh Deer Exclusion Fence, The Education Store, Purdue Extension Resource Center
Electric Fences for Preventing Deer Browse Damage by White-Tailed Deer, The Education Store
Managing Your Woods for White-Tailed Deer, The Education Store
How to Score Your White-Tailed Deer, Video, Purdue Extension Youtube Channel
Lenny Farlee, Sustaining Hardwood Extension Specialist
Purdue University Department of Forestry and Natural Resources
Purdue Forestry & Natural Resources extension specialists gathered for a Facebook LIVE event held May 5th to answer questions on a wide range of topics from woodland management to wildlife habitat, ponds to invasive species and more.
Topics ranged from what to do about moles, voles and Canada geese causing damage in your yard, to how to pick the right tree for your landscape and how to measure the worth of your trees. The presentation also included segments on what to do about algae in your pond to how to know if you need to restock it as well as what to do about invasive plant species and how to protect your trees from deer damage.
Get advice from extension specialists Jarred Brooke, Lenny Farlee, Brian MacGowan, Lindsey Purcell, Rod Williams and Mitch Zischke in the video below.
If you have any further questions feel free to send your questions by submitting our Ask An Expert form.
Resources mentioned:
Purdue Extension – The Education Store
Purdue Report Invasive Species Website
Midwest Invasive Species Network Database
TreesAreGood.org
Find a Forester in Indiana
Improve My Property for Wildlife, Purdue Extension
Online Mole Program, Event May 14th, Purdue FNR Extension
Have you seen a hairless squirrel, Got Nature? Blog, Purdue FNR Extension
Stocking Fish, The Education Store, Purdue Extension Resource Center
Tree Selection for the “Un-natural” Environment, The Education Store
Selecting a Nuisance Control Operator, The Education Store
Forest Products Price Report (pdf), Indiana Department of Natural Resources (IDNR)
Indiana DNR Nuisance Goose Control Options (pdf), Indiana Department of Natural Resources (IDNR)
Turtles of Indiana, The Education Store
Salamanders of Indiana, The Education Store
Frogs and Toads of Indiana, The Education Store
Snakes and Lizards of Indiana, The Education Store
Aquatic Plant Management, The Education Store
Native Grasses, The Education Store
Preventing Deer Browsing on Trees/Shrubs, Video, Purdue Extension Youtube Channel
Brian MacGowan, Wildlife Extension Specialist
Purdue University, Department of Forestry and Natural Resources
Our recent cold mornings resulted in late freeze damage to many trees and shrubs. This damage to newly emerging shoots and leaves follows a few hours of temperatures below the freezing mark. Damage is usually characterized by wilting browning of new growth, particularly leaves and needles. It may take a few days, or until temperatures begin warming again, for damage to become evident.
The photos below reveal some late freeze damage in southern Indiana, shared by a concerned tree owner. It is often dramatic and can cause concern for homeowners and landscapers. Fortunately, the damage is largely aesthetic, and plants will quickly resume growth.
What can you expect? Typically, the damaged or dead leaves will fall and new leaves will emerge, although somewhat slowly. A reduction in growth and leaf size can be anticipated as well. Just remain calm and wait for the tree to recover. If the tree was vigorous going into winter and had a good store of carbohydrates, it can withstand an environmental hit such as these cold extremes.
If branches or stems don’t show any evidence of bud or leaf emergence, lightly scratch the bark with your thumbnail. If the green cambial layer is revealed, the tree is likely just slowly emerging from dormancy. If there is no green tissue evident, it is likely dead. Prune out the dead branches to a living later branch and assess the plant.
Resources
Question: What are these pretty green flower shaped growth spots? Will they damage the tree?, Got Nature? Post, Purdue FNR Extension
Iron Chlorosis of Trees and Shrubs, The Education Store, Purdue Extension resource center
Tree Diseases: Oak Wilt in Indiana, The Education Store
Tree Diseases: White Pine Decline in Indiana, The Education Store
Mechanical Damage to Trees: Mowing and Maintenance Equipment, The Education Store
Surface Root Syndrome, The Education Store
Tree Appraisal and the Value of Trees, The Education Store
Lindsey Purcell, Urban Forestry Specialist
Purdue University, Department of Forestry and Natural Resources
For such a small creature, moles can cause big headaches. Their tunneling behavior can cause extensive damage to turf areas if left unchecked. While the damage is easy to identify, solving it can be tricky.
Purdue wildlife specialist, Brian MacGowan, shared tips and control techniques including trapping, repellents, toxicants, and cultural methods as well as answer your questions on the topic on Facebook LIVE, Thursday, May 14th.
You can view this topic along with question and answer time on the Purdue FNR Facebook page: https://www.facebook.com/PurdueFNR/videos/3372718849422210/.
If you have any further questions feel free to place your question in the comment section on our Purdue FNR Facebook page on the video link above or you can send your question by submitting an Ask An Expert form.
Resources
Moles, The Education Store, Purdue Extension resource center
Adjuvants and the Power of the Spray Droplet: Improving the Performance of Pesticide Applications, The Education Store
Preventing Wildlife Damage – Do You Need a Permit?, The Education Store
Attract Hummingbirds to Your Yard, Video, Purdue Extension Youtube Channel
How to Stop Woodland Animals from Digging in Your Flower Pots, Video, Purdue Extension Youtube Channel
Brian MacGowan, Wildlife Extension Specialist
Purdue Forestry and Natural Resources
Question:
Are these pretty green flower shaped growth spots lichens? It just appeared on my tree this year. With this type of fungus should I be worried that it could damage the tree?
Answer:
Lichen is common on trees and not bad either. Those grayish-green patches, come in all sizes and shapes and sometimes covering much of the tree, are not feeding on your woody plants. Lichens grow on the surface of the tree, and do not penetrate any tissue. Instead, they make use of the trunk or branches for support. They can be aesthetically pleasing for many. Lichens play a very significant role as a bio-indicator. They only grow where the air quality is good and have a favorable growing environment. They help filter the air as well… so, don’t worry, be happy!
Resources:
Lichens, Purdue Botany & Plant Pathology
Purdue Plant & Pest Diagnostic Lab, Purdue Botany & Plant Pathology
Diseases of Landscape Plants: Leaf Diseases, The Education Store, Purdue Extension resource center
Surface Root Syndrome, The Education Store
Tree Installation: Process and Practices, The Education Store
Purdue Landscape Report, Purdue University
Lindsey Purcell, Urban Forestry Specialist
Purdue University, Department of Forestry and Natural Resources
While our FNR Purdue Extension specialists can’t be with you in person at workshops, meetings or in the field right now, they are still here to assist you. Don’t hesitate to reach out.
Purdue Extension – Forestry and Natural Resources, purdue.edu/fnr/extension
Ask An Expert
Wendy Mayer, Communications Coordinator
Purdue University Department of Forestry and Natural Resources
Diana Evans, Extension & Web Communications Specialist
Purdue University Department of Forestry and Natural Resources
Many trees, shrubs, and other ornamental plantings in Indiana and throughout the Midwest suffer from iron deficiency caused by high pH (alkaline) soil. Soil pH affects plant growth directly and indirectly by affecting the availability of essential nutrients and microbial activity. One of these nutrients is iron, an essential plant nutrient that is required for the production of chlorophyll. Chlorophyll is necessary for photosynthesis and gives plants their green color. Iron (and manganese) deficiency results in leaf yellowing (chlorosis); over time, scorching of foliage, dieback and even death of the tree or shrub can result.
Iron Chlorosis of Trees and Shrubs talks about the symptoms, the cause and the managing of iron chlorosis. One of the authors is Lindsey Purcell, an urban forestry specialist from the Department of Forestry and Natural Resources at Purdue University.
This 5-page publication is part of the Plant Pathology in the Landscape Series and is a free download from the Purdue Extension resource center, The Education Store. View other tree disease publications and video resources as you place keywords in the search field located on The Education Store website.
Resources
Tree Diseases: Oak Wilt in Indiana, The Education Store, Purdue Extension resource center
Tree Diseases: White Pine Decline in Indiana, The Education Store, Purdue Extension resource center
Mechanical Damage to Trees: Mowing and Maintenance Equipment, The Education Store, Purdue Extension resource center
Surface Root Syndrome, The Education Store, Purdue Extension resource center
Tree Appraisal and the Value of Trees, The Education Store, Purdue Extension resource center
Lindsey Purcell, Urban Forestry Specialist
Purdue University, Department of Forestry and Natural Resources
Purdue Landscape Report: We all have heard about dormancy and the restful time of woody plants in our landscapes. That “chill-out” time is nearing the end and it’s time to think about tree maintenance. Trees and shrubs have actually been growing for quite some time, we just can’t see it… yet. Woody plants begin growth after the chilling requirements have been filled. These requirements are different for every plant. Chilling units are hours of time spent above freezing. The number of hours required for chilling varies for different plants from less than 500 to 1,500 hours or more. Many people think the plant is tracking hours below freezing, but in actuality, hours below freezing has no effect on chilling but does increase cold hardiness. Our mild winter and early spring arrival is playing a role in this process.

Figure 1. These oak tree buds may look dormant but have completed their chilling requirement and are ready to break. Source
An important maintenance task is supplemental fertilization during early spring weather, especially if there wasn’t any type of fall fertilization. Let’s take a look at how a tree uses and gains energy during the year to understand why and when trees need good nutrition. After the leaves have fallen there is no way to generate food because without leaves, there is no photosynthesis. There are huge demands on the carbohydrate reserves due to increased metabolic functions to support new leaves, flowers and fruit. Supplemental nutrition can help if storage levels are low or depleted until the new photosynthates are available. That’s a huge demand on its reserves! The tree must rely on stored carbohydrate reserves in its woody parts such as stems and branches to grow. Hopefully, the tree was healthy and developing those reserves going into fall or supplemental nutrition was offered with fall fertilization. If not, then the tree exhausts much of its energy and is in need of new resources. In some situations, it may be considered safer for the tree to apply fertilizer in the spring. Fall applications, if applied too early in the fall season, can create the risk of forcing the plant into becoming metabolically active right when cold weather hits, creating growth susceptible to freeze damage.
Many woody plants begin the new year’s growth with stored food from the year before. An application of fertilizer in the spring gives an additional boost to this new growth. It is important to note that not all trees and shrubs need fertilization, however, most can benefit from this application, especially the younger actively growing trees. In forests, soils have an abundance of nutrients, but in our landscapes and urban forest areas, that’s not often the case. As we sweep away leaves, twigs and fallen bark, we’re removing potential recycling of nutrients for the soil. Additionally, the grass around our trees is unnatural and often outcompetes trees for available nutrients and water. That’s why we need to fertilize our trees, spring or fall. Look for signs that your tree is lacking nutrients in the soil. If you see these signs, fertilization may be necessary.

Figure 2. The graph shows the starch loss or energy used during various growing stages for the tree during the year. Most energy is depleted after leaf emergence and then regained as leaves begin photosynthesizing new resources. Source
However, never fertilize without getting a soil test. If your trees are experiencing any of the above symptoms, have your local arborist inspect the tree to determine the best treatment. Also, Review Consumer Horticulture: Fertilizing Woody Plants (pdf) for more details on fertilizer application techniques and rates.
Now for just a little about tree pruning. All of that new tree growth is going to prompt the pruning activities… be patient! Once trees start budding and blooming in the spring hold off until after the flush. Pruning in the spring can limit bloom potential and remove newly expanding leaves that will be needed to produce new food products for energy.
Generally, the best time to prune is several weeks after the spring flush or during the summer months. Early spring pruning should focus primarily on pruning for safety to remove any dead, dying or decayed branches. Aesthetic or structural pruning can be completed much later and when the tree is better prepared to seal those pruning wounds with energy reserves. For more information refer to the publication Tree Pruning Essentials from the Education Store on pruning topics.
Resources
Consumer Horticulture: Fertilizing Woody Plants, The Education Store, Purdue University
Tree Planting Part 1: Choosing a Tree, Video, The Education Store
Tree Installation: Process and Practices, The Education Store
Tree Pruning Essentials, Video
Corrective Pruning for Deciduous Trees, The Education Store
Tree Pruning: What Do Trees Think?, The Education Store
Lindsey Purcell, Urban Forestry Specialist
Purdue University, Department of Forestry and Natural Resources