Got Nature? Blog

In this webinar, hosted by Indiana Forestry & Woodland Owners Association (IFWOA), presenter LeAnne Barta of Indiana Lyme Connect shares strategies for preventing tick bites and discuss the ticks found in Indiana, their life stages, and symptoms of tick-borne illnesses like Lyme disease.

Check out the Indiana Forestry & Woodland Association YouTube Channel for videos including: What is IFWOA?; A New Carbon Program for Hardwood Landowners Webinar, Indiana’s Native Orchids, Magnificent Trees of Indiana, Observing Seasonal Changes in Nature and much more.

The Indiana Forestry & Woodland Owners Association (IFWOA) was founded in 1977 and is a non-profit organization dedicated to conservation and sustainable management of woodlands in Indiana. IFWOA advocates for scientific best practices for management to achieve objectives of clean water, wildlife habitat, soil protection, native species diversity, timber production, recreation, carbon sequestration and many others.

IFWOA is an affiliate of the National Woodland Owners Association. IFWOA is a partner, collaborator or is represented on leading National and State organizations. These memberships or collaborations are selected to advance Indiana Woodland owner’s interests. IFWOA monitors and influences legislation and economic trends impacting Indiana woodlands and landowners for our members. Membership in IFWOA provides a valuable network linkage to information and resources at the leading edge of science, industry and politics impacting Indiana woodlands.

Resources:
Find an Indiana Professional Forester, Indiana Forestry & Woodland Owners Association (IFWOA)
Purdue Arboretum Explorer
Native Trees of the Midwest, Purdue University Press
Shrubs and Woody Vines of Indiana and the Midwest, Purdue University Press
Investing in Indiana Woodlands, The Education Store
Forest Improvement Handbook, The Education Store
ID That Tree, Purdue Extension-Forestry & Natural Resources (FNR) YouTube playlist
Woodland Management Moment , Purdue Extension-FNR YouTube playlist

Liz Jackson, Engagement Lead
Indiana Forestry & Woodland Association


MyDNR, Indiana’s Outdoor Newsletter: During the spring and summer please let us know if you think you may have seen spotted lanternfly by contacting us at 866-NO-EXOTIC (866-663-9684), or by email at DEPP@dnr.IN.gov. Please be sure to provide your contact information and detailed information about the location. Early detection is crucial to successful spotted lanternfly management efforts.Spotted lanternfly on tree limb.

Spotted lanternfly is a major pest of concern across most of the United States. This insect is native to China and parts of India, Vietnam, Japan, and Taiwan. It was first identified as an invasive species in 2004 in South Korea and is now a major pest there. Spotted lanternfly was first detected in the United States in Pennsylvania in 2014.

In July 2021, a population of spotted lanternfly (Lycorma delicatula) was identified in Indiana in Switzerland County, near the Ohio River. A second population was found in Huntington, Indiana in July 2022. DEPP and USDA continue to conduct surveys to ascertain the extent and source of these infestations as well as determine what management strategies will be implemented.

Newsletter can be found online:  MyDNR Email Newsletter

For more information please visit Spotted Lanternfly – MyDNR

Resources:
Spotted Lanternfly, Indiana Department of Natural Resources Entomology
Spotted Lanternfly Found in Indiana, Purdue Landscape Report
Invasive plants: impact on environment and people, The Education Store, Purdue Extension’s resource center
Woodland Management Moment: Invasive Species Control Process, Video, Purdue Extension – Forestry and Natural Resources (FNR) YouTube Channel
Invasive Species, Playlist, Purdue Extension – FNR YouTube Channel
What are invasive species and why should I care?, Got Nature? Blog, Purdue Extension – FNR
Report Invasive, Purdue College of Agriculture – Entomology

Indiana Department of Natural Resources, Department of Fish & Wildlife


In this episode of ID That Tree, Recep Yildiz a FNR graduate student shares his expertise on how to ID black alder. Black alder, which is also known as common alder or European alder, is found in most of Europe and extends into North Africa and Asia. It is easily identified by its gummy twigs and leaves. Learn more about the black alder tree and how it was introduced to Indiana with now current warning signs of being an invasive species.

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 (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
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
Spotted Lanternfly Feeds on Over 70 Plus Plant Species, Got Nature? Blog, Purdue Extension – FNR
Shrubs and Woody Vines of Indiana and the Midwest, The Education Store, Purdue Extension Resource Center
Native Trees of the Midwest, The Education Store
Investing in Indiana Woodlands, The Education Store
Forest Improvement Handbook, The Education Store

Recep Yildiz, FNR graduate student
Purdue Department of Forestry & Natural Resources


In this episode of ID That Tree, Recep Yildiz a FNR graduate student shares his expertise on how to ID Persian walnut or sometimes called common walnut or English walnut. It is not native to Indiana but is widely cultivated and grown for nuts. This species is deciduous and native to Europe, the Himalayas and China. Learn more about Persian walnut and along with clear photos of the bark and 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 (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
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
Spotted Lanternfly Feeds on Over 70 Plus Plant Species, Got Nature? Blog, Purdue Extension – FNR
Shrubs and Woody Vines of Indiana and the Midwest, The Education Store, Purdue Extension Resource Center
Native Trees of the Midwest, The Education Store
Investing in Indiana Woodlands, The Education Store
Forest Improvement Handbook, The Education Store

Recep Yildiz, FNR graduate student
Purdue Department of Forestry & Natural Resources


Image of Volcano mulching around the base of the tree

Figure 1: Volcano mulching around the base of the tree. Photo credit Lindsey Purcell.

Purdue Landscape Report: It’s that wonderful time of year again where temps are rising, life is coming back into the landscape, and people are thinking about how to improve the urban canopy around them.  Well, maybe not that specifically, but we have the urge to plant trees.  Whether it’s for Earth Day or Arbor Day or you just enjoy the act of planting, one of the hot topics is getting trees into the ground.  That’s not what I’m here to talk about today, though.

As much as I love assisting communities with their greening efforts, getting the right tree in the right place, planting is not the only way to help grow the canopy around you.  One of the topics that can be neglected is maintaining trees from previous plantings.  Often, trees get placed in the ground, they are mulched, watered, and staked, then left on their own to make it in the world.  New trees can take about 2-5 years to become established in their new homes and they could require assistance from us for much longer to thrive.  Luckily, there is a simple activity to do assist trees, young and old.

Just like when they were placed in the ground, trees still benefit from mulch.  Reapplying mulch benefits trees in multiple ways.  It’s a natural way to prevent weeds and grass competing in the root zone and adds a protective buffer against mechanical damage from mowers and weed eaters.  It will also help to maintain moisture levels in the soil as we transition into the hotter summer months.  When applying new mulch, don’t worry about removing the old layer.  It’s working its way into the soil around the tree adding organic matter, improving the quality of the soil.

Image of correct application of mulch

Figure 2: Correct application of mulch. Photo Credit John Bonkowski.

Add enough mulch so there is a 2–3-inch layer sloping away from the tree with at least a 3–5-foot radius around the stem (older, larger trees can benefit from larger mulch rings).  No volcano mulching (Figure 1), make sure you also have around a 1-2-inch gap between the stem and the start of the mulch ring (Figure 2) to prevent unwanted root growth above ground and rot from excess moisture on the stem.   Continuing this practice every year can help maintain soil moisture levels, while enriching the soil around your tree, maintaining a safety zone, and adding a nice aesthetic.

To view this article and other Purdue Landscape Report articles, please visit Purdue Landscape Report.

Subscribe and receive the newsletter: Purdue Landscape Report Newsletter.

Resources:
The Purdue Landscape Report
Purdue Landscape Report Facebook Page
Find an Arborist website, Trees are Good, International Society of Arboriculture (ISA)
Tree Installation: Process and Practices, The Education Store
Planting Forest Trees and Shrubs in Indiana, The Education Store
Planting Your Tree Part 1: Choosing Your Tree, Video, Purdue Extension – Forestry and Natural Resources YouTube Channel
Tree Defect Identification, The Education Store, Purdue Extension resource center
Tree wounds and healing, Got Nature? Blog
Tree Pruning Essentials, Publication & Video, The Education Store
Shrubs and Woody Vines of Indiana and the Midwest, The Education Store
Tree Risk Management, The Education Store
Why Is My Tree Dying?, The Education Store
ID That Tree, Purdue Extension-Forestry & Natural Resources (FNR) YouTube playlist
Subscribe to Purdue Extension-FNR YouTube Channel

Ben McCallister, Urban Forestry Specialist
Purdue Forestry and Natural Resources

 


Image of bacterial leaf spots are often angular with chlorotic halos

Bacterial leaf spots are often angular with chlorotic halos, as seen on this high bush-cranberry. Photo by Janna Beckerman.

Purdue Landscape Report: Pseudomonas syringae pv. syringae is an opportunistic bacterial pathogen that attacks a diversity of woody ornamental plants. The bacteria cause flower blights, cankers, shoot blights, and diebacks.

Symptoms
Symptoms often begin as expanding leaf spots. On lilac and viburnum, small spots expand to irregularly shaped brown lesions with yellow halos (Fig. 1). For most other hosts (cherry, pear, basswood, dogwood, hydrangea, high bush-cranberry, mountain-ash), infected leaves turn reddish brown or black and usually remain on the branch after they die (Fig. 2). As the bacteria spread into woody tissue, dark, sunken sections of the stem (cankers) expand, working their way back toward the trunk from infected leaves and flowers. Leaves attached to a cankered branch will wilt while the tip of the affected branch curls and droops like a shepherd’s crook (Fig. 3). Cloudy droplets of sticky fluid (ooze) may accumulate on leaf tips, leaf surfaces, stems, and even infected fruit.

Image of infected flowers result in blossom blast.
Figure 2. Infected flowers result in blossom blast. The continued growth of the bacteria can result in cankering and blight. Photo by George Sundin.

Image of infected flowers result in blossom blast.

Figure 2. Infected flowers result in blossom blast. The continued growth of the bacteria can result in cankering and blight. Photo by George Sundin.

Life Cycle
The bacteria overwinter and persist in cankers, along with asymptomatic bud and twig tissue. In presence of water and warming temperatures, bacteria multiply and may ooze from infected tissue. Wind-driven rain, insect, or mechanical pruning spread Pseudomonas. Bacteria enter the plant through flowers or injury.

Management
All bacterial pathogens, including Pseudomonas, invade flowers or wounded tissue. To prevent or minimize the risk of infection:

  • Use disease-free plants and budwood.
  • Prune in the late winter/early spring.
  • When pruning, do not mix pruning to shape woody ornamentals with pruning to manage disease.
  • When pruning to remove infected shoots, be sure to disinfect shears between plants.
  • Minimize overhead irrigation when possible to minimize splashing and pathogen spread.
  • Avoid over-fertilization practices that drive excess succulent growth.

    Image of bacterial blight is a common scourge to common lilac

    Figure 3. Bacterial blight is a common scourge to common lilac. Using resistant varieties is the best way to protect against the disease. Photo by Janna Beckerman.

  • Avoid late season fertilization practices that prevent plants from achieving timely dormancy and promote freeze damage and/or winter injury (Fig. 4).
  • Choose zone appropriate plants to avoid freeze damage and/or winter injury.
  • Choose disease resistant plants, when available. The following lilac varieties were found to be resistant over a four-year trial: Donald Wyman, Royalty, Superba, Miss Kim, Edmund Boisier, Victor Lemoine, Dwarf Korean, Mme. Antoine Buchner Isabella, Sensation, Anna Amhof, Krasavitska Moskvy, Michael Buchner, and Alphonse Lavallée.

Foliar sprays of some copper-based bactericides (e.g., Camelot, Kocide, and Nu-Cop) were found to reduce disease incidence in trials on lilac (Vey and Palmer, 2018). Avoid using copper under cool, humid conditions to reduce the risk of phytotoxicity and damaging plants. Copper resistant populations of Pseudomonas syringae have been reported in other crops (vegetables, stone fruit). Products containing acibenzolar have provided inconsistent control in multiple trials but is labeled for use. Use of quaternary-ammonium disinfestants (KleenGrow) have been found to reduce bacterial populations and disease incidence and should be considered as part of any rotation with copper products. Due to the diversity of copper products, be sure to test for phytotoxicity issues prior to large scale treatment of crops.

To view this article and other Purdue Landscape Report articles, please visit Purdue Landscape Report.

Subscribe and receive the newsletter: Purdue Landscape Report Newsletter.

Resources:
The Purdue Landscape Report
Purdue Landscape Report Facebook Page
Find an Arborist website, Trees are Good, International Society of Arboriculture (ISA)
Phytophthora Diseases in Ornamentals, The Education Store, Purdue Extension’s resource center
Root Rot in Landscape Plants, The Education Store
Symptoms and Signs for Plant Problem Diagnosis, The Education Store
Tree Defect Identification, The Education Store
Tree Pruning Essentials, Publication & Video, The Education Store
Shrubs and Woody Vines of Indiana and the Midwest, Purdue University Press
Tree Risk Management, The Education Store
Equipment Damage to Trees, Got Nature? Blog
Tree wounds and healing, Got Nature? Blog
ID That Tree, Purdue Extension-Forestry & Natural Resources (FNR) YouTube playlist
Southwest Damage, Scalding, or Frost Cracking – Landscape Report
Subscribe to Purdue Extension-FNR YouTube Channel

Janna Beckerman, Professor of Plant Pathology
Purdue Department of Botany


This exotic invasive tree species is commonly found in Indiana landscape, callery pear. Callery pear has been planted as an ornamental tree in the midwest for decades. The original selection bradford pear was actually infertile and would not spread from seed but additional varieties have been planted and have crossed with the original Bradford and those are producing fertile seed. Find out how the seed spreads and what we can do to help our forest.

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 (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
Shrubs and Woody Vines of Indiana and the Midwest, The Education Store, Purdue Extension Resource Center
Native Trees of the Midwest, The Education Store
Investing in Indiana Woodlands, The Education Store
Forest Improvement Handbook, The Education Store

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


The classic and trusted book “Fifty Common Trees of Indiana” by T.E. Shaw was published in 1956 as a user-friendly guide to local species.  Nearly 70 years later, the publication has been updated through a joint effort by the Purdue Department of Forestry and Natural Resources, Indiana 4-H, and the Indiana Department of Natural Resources, and reintroduced as “An Introduction to Trees of Indiana.”

The full publication is available for download for $7 in the Purdue Extension Education Store. The field guide helps identify common Indiana woodlot trees.

Image of Jack pine tree needles

Each week, the Intro to Trees of Indiana web series will offer a sneak peek at one species from the book, paired with an ID That Tree video from Purdue Extension forester Lenny Farlee to help visualize each species as it stands in the woods. Threats to species health as well as also insight into the wood provided by the species, will be provided through additional resources as well as the Hardwoods of the Central Midwest exhibit of the Purdue Arboretum, if available.

This week, we meet the Jack pine, or Pinus banksiana.

This conifer, also known as scrub pine, has clusters of two dark green needles, which are one to one and a half inches long, noticeably curved or arched like a bow and slightly twisted.

Bark on the jack pine is dark to medium gray, thin and flaky when young and features thick plates in older trees. This tree growth irregularly and can produce between one and three whorls of side branches annually. It tends to have a much lighter crown than white pine or the spruces.

The cones of jack pine are one to three inches long and remain closed while on the tree unless disturbed by a heat event such as fire. The cones may also be curved and twisted into many irregular shapes and tend to stay on the tree for many years.

For full article with additional photos view: Intro to Trees of Indiana: Jack Pine, Forestry and Natural Resources’ News.

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.

Other Resources:
ID That Tree: Jack Pine
Morton Arboretum: Jack Pine
Jack Pine, Native Trees of Indiana River Walk, Purdue Fort Wayne
Borers of Pines and Other Needle Bearing Evergreens in Landscapes, The Education Store, Purdue Extension’s resource center
Managing the Zimmerman Pine Moth, The Education Store
Purdue Arboretum Explorer
The Woody Plant Seed Manual, U.S. Forest Service
Native Trees of the Midwest, The Education Store
Shrubs and Woody Vines of Indiana and the Midwest, The Education Store
Investing in Indiana Woodlands, The Education Store
Forest Improvement Handbook, The Education Store
ID That Tree, Purdue Extension-Forestry & Natural Resources (FNR) YouTube playlist
Woodland Management Moment , Purdue Extension-FNR YouTube playlist

Wendy Mayer, FNR Communications Coordinator
Purdue University Department of Forestry and Natural Resources

Lenny Farlee, Extension Forester
Purdue University Department of Forestry and Natural Resources


The classic and trusted book “Fifty Common Trees of Indiana” by T.E. Shaw was published in 1956 as a user-friendly guide to local species.  Nearly 70 years later, the publication has been updated through a joint effort by the Purdue Department of Forestry and Natural Resources, Indiana 4-H, and the Indiana Department of Natural Resources, and reintroduced as “An Introduction to Trees of Indiana.”

The full publication is available for download for $7 in the Purdue Extension Education Store. The field guide helps identify common Indiana woodlot trees.

Image of scotch pine needles and cones

Each week, the Intro to Trees of Indiana web series will offer a sneak peek at one species from the book, paired with an ID That Tree video from Purdue Extension forester Lenny Farlee to help visualize each species as it stands in the woods. Threats to species health as well as also insight into the wood provided by the species, will be provided through additional resources as well as the Hardwoods of the Central Midwest exhibit of the Purdue Arboretum, if available.

This week, we meet the scotch pine, or Pinus sylvestris, which is not native to Indiana, but has been widely planted in the state for Christmas tree production.

This conifer, also known as Scots pine, has clusters of two blue green or yellow green needles, which are one to three inches long and do not break when bent.

Bark on the scotch pine is light gray on the outside and orange in color on the inner bark, but it is not flaky like red pine. Bark on the lower end of the trunk is dark and blocky, while the upper bark is more orange.

On the tree, cones are cylindrical and pointed at the ends, approximately three inches long and do not have spines at the end of the scales. Cones become more egg shaped as the scales begin to open up once off the tree.

Scotch pine, which grows to between 25 and 60 feet tall, is typically found on acidic, moist, well-drained soil. It prefers full sun and has some drought tolerance. The species’ native range is Scotland, Scandinavia, northern Europe and northern Asia. According to the U.S. Forest Service database, It has been introduced across the United States and Canada and is naturalized in the Northeast and in the Great Lakes states.

For full article with additional photos view: Intro to Trees of Indiana: Scotch Pine, Forestry and Natural Resources’ News.

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.

Other Resources:
ID That Tree: Scotch Pine
Morton Arboretum: Scotch Pine
A Choose-and-Cut Pine and Fir Christmas Tree Case Study
Diplodia Tip Blight of Two-Needle Pines, The Education Store, Purdue Extension’s resource center
Borers of Pines and Other Needle Bearing Evergreens in Landscapes, The Education Store
America’s Least Wanted Wood-Borers, Japanese Pine Sawyer, The Education Store
Managing the Zimmerman Pine Moth, The Education Store
Purdue Arboretum Explorer
The Woody Plant Seed Manual, U.S. Forest Service
Native Trees of the Midwest, The Education Store
Shrubs and Woody Vines of Indiana and the Midwest, The Education Store
Investing in Indiana Woodlands, The Education Store
Forest Improvement Handbook, The Education Store
ID That Tree, Purdue Extension-Forestry & Natural Resources (FNR) YouTube playlist
Woodland Management Moment , Purdue Extension-FNR YouTube playlist

Wendy Mayer, FNR Communications Coordinator
Purdue University Department of Forestry and Natural Resources

Lenny Farlee, Extension Forester
Purdue University Department of Forestry and Natural Resources


Image of spruce tree.

Figure 1: A spruce tree showing significant needle loss and dieback lower in the canopy.

Purdue Landscape Report: There have been a number of samples we have received at the PPDL in recent weeks that bear similar problems worth noting. It is still relatively early for significant in-season disease development due to how cold it has been, although we have certainly had enough rainfall to encourage fungal growth. We have received multiple samples of spruce and boxwood which will be covered.

Since the start of the year, we have been received spruce samples showing needle thinning, browning, and loss in the lower canopy (Fig 1, 2, 3). If I said these are Colorado Blue Spruce, we could call it Rhizosphaera and maybe call it a day, however, these samples are primarily from other species of spruce. An important thing to remember when it comes to evergreen conifers is that it takes time for symptoms to develop, whether due to disease or to abiotic factors. The majority of these branches lacked any discoloration within, suggesting that there was no infection and that the limbs were still living.

Last year, we had drought conditions during the summer throughout large parts of the state leading into the fall with below average precipitation (Fig 4). Since evergreen plants hold onto their foliage through the winter, desiccation can occur since they are still losing water to the air, especially when it is dry and windy. If these plants are not getting enough water going into winter, there is greater risk of winter injury or burn and needles may turn brown, especially near branch tips (exposed areas).

Image of needle loss near branch tips

Figure 2: Needle loss at or near branch tips.

Close up image of needle browning and loss on the tip

Figure 3: Close up of needle browning and loss near spruce branch tips.

Irrigation during periods of hot and dry weather will mitigate drought stress, but irrigation may still be necessary in the fall to avoid needle desiccation. What about when trees of the same age, on the same property are showing different levels of severity or one tree is perfectly fine while the next is toast?

I think it is important to remember each tree is an individual. We may see similar patterns in the landscape across the same tree species when stress is caused by environmental effects, but if the overall health of that tree when it was first planted, the amount of love and care, and the site conditions (soil, light, general water levels) are different, then the trees may have vastly different reactions to stress. Determining this 5 years after planting can be difficult for someone just walking into the situation, or when dealing with 30ft tall trees, but it is something we have to keep in mind.

Image of Indiana Precipitation data.

Figure 4: Indiana Precipitation data, in inches of rainfall, from 2019 to present.

For more images and full article view: Early Season Samples: Spruce Needle Loss and Boxwood Leaf Spots

Subscribe and receive the newsletter: Purdue Landscape Report Newsletter.

Resources:
The Purdue Landscape Report
Purdue Landscape Report Facebook Page
Find an Arborist website, Trees are Good, International Society of Arboriculture (ISA)
Equipment Damage to Trees, Got Nature? Blog
Tree wounds and healing, Got Nature? Blog
Tree Defect Identification, The Education Store, Purdue Extension resource center
Tree Pruning Essentials, Publication & Video, The Education Store
Shrubs and Woody Vines of Indiana and the Midwest, The Education Store
Tree Risk Management, The Education Store
Why Is My Tree Dying?, The Education Store
ID That Tree, Purdue Extension-Forestry & Natural Resources (FNR) YouTube playlist
Subscribe to Purdue Extension-FNR YouTube Channel

John Bonkowski, Plant Disease Diagnostician
Departments of Botany & Plant Pathology


Got Nature?

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