Got Nature? Blog

Purdue Landscape Report: Just after the browned leaves on branches of trees attacked by periodical cicadas began to disappear from view, webworms and their associated browning started to spread through the landscape. Two of the more common webworms I have been seeing are the mimosa and the fall webworm. While neither of them can outright kill trees, they are unsightly, especially at the end of the summer when substantial portions of the tree are disfigured. Treatment late in the summer does little to reduce injury, because it can be difficult to penetrate the webs with insecticides, and because most of the damage has already been done. The best course of action is to plan on managing these insects next year, when they are more easily controlled with insecticides.

Fall webworm attacks a wide range of deciduous trees including flowering fruit trees, black walnuts, elm, hickory and bald cypress. They are most common in suburban areas, roadsides and forest edges that lack the predators and parasites the webworms encounter in the forest. In June adults emerge from wintering sites to lay eggs in the canopy. Eggs hatch into caterpillars that encase branches in webs as they feed. By the end of the second generation in late August webs can cover substantial portions of trees. Caterpillars are yellowish-green with black spots and long white hairs, and grow up to 1.5″. Caterpillar feces falling from trees can be a problem during heavy infestations.

Unlike fall webworm, the mimosa webworm only attacks honeylocust and mimosa trees. Leaves on ends of branches become webbed together and turn brown as lime-green caterpillars skeletonize leaf tissue. Heavily infested trees appear frosted brown. In early June, adults emerge and lay eggs on trees. First webs can be seen on ends of branches in mid-June when oak leaf hydrangea and tree lilac are in bloom. The second generation of adults fly and lay eggs starting in late July. A third generation occurs in the fall. The dangling caterpillars can be a nuisance under heavily infested trees. We are seeing an uptick in the abundance of this pest because the last two winters have not been cold enough to kill them.

Full Article >>>

Resources:
Purdue Landscape Report
Ask an Expert, Purdue Extension – Forestry and Natural Resources
Purdue Plant Doctor App Suite, Purdue Extension – Entomology
Landscape & Ornamentals: Bagworms, The Education Store, Purdue Extension
Bagworm caterpillars are out feeding, be ready to spray your trees, Got Nature? Post, Purdue Extension – Forestry and Natural Resources
Fall Webworms: Should You Manage Them, Got Nature? Post, Purdue Extension – Forestry and Natural Resources

Purdue Extension – Entomology

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On this edition of ID That Tree, meet the American hornbeam, also known as the musclewood or the water or blue beech. This native Indiana understory tree stands out due to its gray bark and striations that resemble muscles and sinews as well as its doubly toothed leaves.

If you have any questions regarding wildlife, trees, forest management, wood products, natural resource planning or other natural resource topics, feel free to contact us by using our Ask an Expert web page.

Resources:
ID That Tree, Playlist, Purdue Extension – Forestry and Natural Resources Youtube Channel
A Woodland Management Moment, Playlist, Purdue Extension – FNR Youtube Channel
Shrubs and Woody Vines of Indiana and the Midwest, Purdue University Press
Native Trees of the Midwest, Purdue University Press
Investing in Indiana Woodlands, The Education Store
Forest Improvement Handbook, The Education Store
American Hornbeam, The Purdue Arboretum Explorer

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

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In this edition of ID That Tree, Purdue Extension forester Lenny Farlee introduces you to a member of the Indiana maple family that doesn’t follow the rest of its family’s traditions. Learn about the boxelder and its unique traits inside.

If you have any questions regarding wildlife, trees, forest management, wood products, natural resource planning or other natural resource topics, feel free to contact us by using our Ask an Expert web page.

Resources:
ID That Tree, Playlist, Purdue Extension – Forestry and Natural Resources Youtube Channel
A Woodland Management Moment, Playlist, Purdue Extension – FNR Youtube Channel
Shrubs and Woody Vines of Indiana and the Midwest, Purdue University Press
Native Trees of the Midwest, Purdue University Press
Investing in Indiana Woodlands, The Education Store
Forest Improvement Handbook, The Education Store
Boxelder, The Purdue Arboretum Explorer

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

 

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In this episode of A Woodland Management Moment, Purdue Extension forester Lenny Farlee talks about a variety of hand tools you can use to assist with invasive species control and timber stand improvement on your property if you choose not to use power tools.

If you have any questions regarding trees, forests, wildlife, wood products or other natural resource topics, feel free to contact us by using our Ask an Expert web page.

Resources:
A Woodland Management Moment, Playlist, Purdue Extension – Forestry and Natural Resources (FNR) YouTube Channel
Shrubs and Woody Vines of Indiana and the Midwest, Purdue University Press
Native Trees of the Midwest, Purdue University Press
Investing in Indiana Woodlands, The Education Store
Forest Improvement Handbook, The Education Store
Woodland Stewardship for Landowners Video Series, Playlist, Indiana Department of Natural Resources YouTube Channel

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

 

 

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In this edition of ID That Tree, Purdue Extension forester Lenny Farlee introduces you to a common understory shrub that features clusters of flowers and simple leaves reminiscent of red maple. Learn more about this native Indiana species inside.

If you have any questions regarding wildlife, trees, forest management, wood products, natural resource planning or other natural resource topics, feel free to contact us by using our Ask an Expert web page.

Resources:
ID That Tree, Playlist, Purdue Extension – Forestry and Natural Resources Youtube Channel
A Woodland Management Moment, Playlist, Purdue Extension – FNR Youtube Channel
Shrubs and Woody Vines of Indiana and the Midwest, Purdue University Press
Native Trees of the Midwest, Purdue University Press
Investing in Indiana Woodlands, The Education Store
Forest Improvement Handbook, The Education Store
Mapleleaf Viburnum, The Purdue Arboretum Explorer

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

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Purdue Landscape Report: Dead leaves covering trees (image 1) or on the ground beneath them (image 2) in July would normally be a worrying sign for tree health, but this year much of the damage can be blamed on 17-year cicadas. This damage is unlikely to cause serious trouble for healthy, large trees and management is relatively simple. The choice to prune or not to prune comes down to cost, aesthetics, and concern for the next generation of cicadas.

How Cicadas Damage Plants

Cicada damage is similar to a light pruning and should not be an issue for healthy, mature trees. Cicadas damage trees when they lay their eggs in small twigs (3/16 to 1/2 inch in diameter) on deciduous trees and shrubs. They have a long, thin body part called an ovipositor that resembles a sewing needle that they stab into plants to lay their eggs. This action creates small holes and cracks in the bark (image 3). If enough cicadas lay their eggs in a twig, it can damage the bark enough to kill the twig (image 1).

Recognizing Cicada Damage
The degree of cicada damage depends on insect density and the number of trees in the area. To determine if a tree or bush has been damaged by cicadas, ask the following questions:

1.  Were there 17-year cicadas within 50 meters (~164 ft) of the tree this year? Cicadas do not travel very far. If there weren’t noticeable numbers of 17-year cicadas nearby the damage was likely caused by something else.
2.  Is the damage on a deciduous tree or bush? Cicadas rarely lay their eggs on evergreen trees and herbaceous plants. Damage on these types of plants is likely caused by something other than the cicadas.
3.  What size of branches and twigs are damaged? Cicadas show a strong preference for small twigs (3/16 to 1/2 inch in diameter). As a result, damaged trees may appear as though their outer layer of leaves is dead while the inner leaves remain healthy (image 2). If larger branches are dead, the damage was probably not caused by cicadas.
4.  Does the bark have typical egg laying damage? If you can reach the damaged twigs, look for a row of puncture wounds often connected by cracks length-wise along the branch. Their appearance may vary between tree species (image 3), but they will almost always be length-wise.

Full Article >>>

Resources:
17 Ways to Make the Most of the 17-year Cicada Emergence, Purdue College of Agriculture
Ask an Expert: Cicada Emergence Video, Got Nature? Blog, Purdue Extension-FNR
Periodical Cicada in Indiana, The Education Store, Purdue Extension resource center
Cicada Killers, The Education Store
Cicada, Youth and Entomology, Purdue Extension
Purdue Cicada Tracker, Purdue Extension-Master Gardener Program
Purdue Landscape Report

Elizabeth Barnes, Exotic Forest Pest Educator
Purdue University Department of Entomology

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In this episode of A Woodland Management Moment, Purdue Extension forester Lenny Farlee talks about the process of invasive species control in woodland areas from the combination of various treatments methods to the timing of those treatments.

If you have any questions regarding trees, forests, wildlife, wood products or other natural resource topics, feel free to contact us by using our Ask an Expert web page.

Resources:
A Woodland Management Moment, Playlist, Purdue Extension – Forestry and Natural Resources (FNR) Youtube Channel
Invasive Species, FNR Playlist
Report Invasive Species, Purdue Invasive Species
The GLEDN Phone App – Great Lakes Early Detection Network
EDDMaps – Early Detection and Distribution Mapping System
Indiana Department of Natural Resources: Invasive Species
Indiana Invasive Species Council
Cooperative Invasive Species Management Area (CISMA)
Woodland Stewardship for Landowners: Environmental Quality Incentives Program (EQIP) -helping with invasive species
Invasive plants: impact on environment and people, The Education Store
What are invasive species and why should I care?, Got Nature? Blog, Purdue Extension
Woodland Invaders, Got Nature? Blog

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

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In this edition of ID That Tree, Purdue Extension forester Lenny Farlee introduces you to a native Indiana shrub that brings explosions of blossoms in the form of white flower clusters in the spring. Meet the blackhaw and learn more about how to identify this shrub inside.

If you have any questions regarding wildlife, trees, forest management, wood products, natural resource planning or other natural resource topics, feel free to contact us by using our Ask an Expert web page.

Resources:
ID That Tree, Playlist, Purdue Extension – Forestry and Natural Resources Youtube Channel
A Woodland Management Moment, Playlist, Purdue Extension – FNR Youtube Channel
Shrubs and Woody Vines of Indiana and the Midwest, Purdue University Press
Native Trees of the Midwest, Purdue University Press
Investing in Indiana Woodlands, The Education Store
Forest Improvement Handbook, The Education Store
Blackhaw, The Purdue Arboretum Explorer

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

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Purdue Landscape Report: Finally, spring has sprung and summer is on its way. The hot days and warm nights are welcome for us, but summer isn’t always so kind to our trees, especially in our urban forests and landscapes. Trees are dynamic living organisms that respond to external stimuli in very strategic ways and each season presents its own challenges and summer is no different.

During the summer, growth slows as some resources become limited and typically, this is water. As the summer season progresses, the likelihood of less rain means potential drought conditions. The primary responses of a tree to heat and drought are a reduction in photosynthesis and carbon assimilation rates. This translates to a reduction in energy production and food reserves. This reduction can increase vulnerability to health issues and reduced defense mechanisms against pests.

There are some key steps to summer tree care which can help trees through potentially challenging conditions in the summer.

1. Watch the water; be sure to supplement trees with additional watering when there isn’t adequate rainfall that measures at least an inch per week. Mature trees need supplemental watering just as the younger, newly established trees. Be sure to know the symptoms of dry conditions and how much to water with more information here.
   

   Drought symptoms should be monitored weekly to prevent decline and dieback during the dry months.

2. Refresh your mulch; adding mulch to tree rings or even better, expanding them is a great way to reduce water requirements and competition for water and other resources. As trees grow, so do the roots under the tree and expanding mulching rings outward to the dripline of the crown is a great way to keep trees healthier. Also, this helps with those surface root issues as well.
   

   Expanding mulch rings is a great way to improve tree root health and reduce surface root issues.

3. Don’t get bugged too much; summer brings out the best in pests too! Many mite and scale species love the heat and can cause major damage and even death to your trees. Look for signs and symptoms of scale infestations and mite damage on your trees and shrubs now. More information on scales can be found here.  Additional details on mite damage can be found here.
4. A nip and tuck are fine; summer is actually a good time to prune as needed to meet objectives such as reducing risk, improving branch structure, and removing conflicts or improving aesthetics. Be sure to only remove what is necessary and reduce the amount of live, green tissue removal. Remember, this is what produces food for the tree. Additional tree pruning techniques are discussed in this publication.
   

   Proper pruning during the summer is a good way to improve aesthetics and stability during stormy weather.

5. Call in a professional; it is always a good idea to consult an ISA Certified Arborist for answers to tree questions. A reputable arborist trained in best practices and current research can provide the best solutions to keeping trees healthy and reduce potential risk for damage during those summer storms. Finding a qualified arborist can be a challenge itself. Refer to this website to find an ISA arborist near you.

For additional information on urban tree care, check out all the publications at the Purdue Education Store.

Resources:
Planting Your Tree Part 1: Choosing Your Tree, Purdue Extension YouTube Channel
Tree Planting Part 2: Planting a Tree, Purdue Extension YouTube Channel
Tree Selection for the “Un-natural” Environment, The Education Store, Purdue Extension resource center
Tree Installation: Process and Practices, The Education Store
Tree Pruning Essentials Video, Purdue Extension YouTube Channel
Tree Defect Identification, The Education Store
Tree Wound and Healing, Got Nature? Blog, Purdue Extension – Forestry and Natural Resources
Surface Root Syndrome, The Education Store
Purdue Landscape Report

Lindsey Purcell, Urban Forestry Specialist
Purdue Department of Forestry and Natural Resources

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