Got Nature? Blog

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.

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. Drawing of swamp white oak leaf.

This week, we take a look at the third of our oak varieties in Indiana, the Swamp White Oak or Quercus bicolor.

The swamp white oak has leaves with wavy, uneven lobed margins with blunt teeth, which are wider toward the tip than at the base. The alternately-held leaves are typically dark green on top with a silvery-white underside, which turn orange, gold and yellow in the fall.

The bark on swamp white oak is similar to that of white oak and often peels back especially on younger trees. Mature bark is dark gray-brown with flaky/shreddy bark or blocky ridges that are consistent up and down the tree.

The fruit of the swamp white oak is an acorn held on a long stalk, typically an inch or inch and a half long, called a peduncle.

Swamp white oaks, which grow to 50 to 60 feet tall, are named for the fact that they often grow in wet places, such asLine drawing of swamp white oak acorns and peduncle. upland swamps and lowlands. This species also can tolerate well-drained upland sites, making it a good option for landscape plantings. The natural range of swamp white oak is the northern half of the eastern United States, reaching as far south as Missouri, southern Illinois and Kentucky, and north into Wisconsin, Michigan and Pennsylvania.

The Morton Arboretum warns to plant swamp white oak in full sun and shares that the species is one of the easiest oaks to transplant and is more tolerant of poor drainage than other oaks. It also notes that oaks should be pruned in the dormant season to avoid attracting beetles that may carry oak wilt. Swamp white oak can be affected by pests such as anthracnose, powdery mildew, chlorosis in high pH soils, insect galls and oak wilt.

In general, lumber from the white oak group is among the heaviest next to hickory, weighing in at 47 pounds per cubic foot. It is very resistant to decay and is one of the best woods for steam bending.

White oak lumber has been used for a variety of purposes including log cabins, ships, wagon wheels and furniture. It also is preferred for indoor decorative applications ranging from furniture, especially in churches, to cabinets, interior trim, millwork and hardwood flooring and veneers. It also may be used for barrel making.

Its density and durability make white oak a favorite for industrial applications such as railroad ties, mine timbers, sill plates, fence posts and boards, pallets, and blocking, as well as industrial, agricultural and truck flooring.

For full article with additional photos view: Intro to Trees of Indiana: Swamp White Oak, 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: Swamp White Oak
ID That Tree: White Oak Group
Hardwood Lumber and Veneer Series: White Oak Group
Morton Arboretum: Swamp White Oak
Fifty Trees of the Midwest app for the iPhone, The Education Store
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, Sustaining Hardwood Extension Specialist
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.

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. Drawing of chestnut oak leaf.

This week, we take a look at the fourth of our oak varieties in Indiana, the Chestnut Oak or Quercus montana.

The leaves of the chestnut oak have small, evenly lobed rounded margins. The upper leaf surface is leathery in appearance and is dark green in color, while the lower surface is a duller green. In the fall, the leaves can range from red and orange to yellow and brown.

The bark may be its tell-tale characteristic. Unlike other members of the white oak group, the bark of Chestnut oak bark chestnut oak is dark and deeply ridged.

The fruit of the chestnut oak is a relatively-large dark brown acorn with a smooth edge on the outer margin of the cap.

Chestnut oaks, which grow to 60 to 70 feet tall, are often found on high, dry sites in Indiana. The natural range of chestnut oak is across the northeastern United States, extending south to the northern parts of Alabama and Georgia and west to the southern tip of Illinois.

The Morton Arboretum warns that chestnut oak is a difficult to transplant due to a deep taproot, but that it can tolerate most soils except those that drain poorly. It also notes that oaks should be pruned in the dormant season to avoid attracting beetles that may carry oak wilt. Chestnut oak can be affected by pests such as scale insects and two-lined chestnut borer. Chestnut oak acorns

In general, lumber from the white oak group is among the heaviest next to hickory, weighing in at 47 pounds per cubic foot. It is very resistant to decay and is one of the best woods for steam bending. Chestnut oak, however, is considered a poor lumber species.

White oak lumber has been used for a variety of purposes including log cabins, ships, wagon wheels and furniture. It also is preferred for indoor decorative applications ranging from furniture, especially in churches, to cabinets, interior trim, millwork and hardwood flooring and veneers. It also may be used for barrel making.

Its density and durability make white oak a favorite for industrial applications such as railroad ties, mine timbers, sill plates, fence posts and boards, pallets, and blocking, as well as industrial, agricultural and truck flooring.

For full article with additional photos view: Intro to Trees of Indiana: Chestnut Oak, 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: Chestnut Oak
ID That Tree: White Oak Group
Hardwood Lumber and Veneer Series: White Oak Group
Morton Arboretum: Chestnut Oak
Fifty Trees of the Midwest app for the iPhone, The Education Store
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
Chestnut Oak, Native Trees of Indiana River Walk, Purdue-Fort Wayne

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

Lenny Farlee, Sustaining Hardwood Extension Specialist
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.

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. Drawing of Bur Oak

This week, we take a look at the second of our oak varieties in Indiana, the Bur Oak or Quercus macrocarpa.

The bur oak has rounded lobes on the end of the leaves, which have deep sinuses and are very broad across the top. Leaves are typically dark green that turn yellow or brown in the fall.

The bark on bur oak is medium to dark gray in color with heavy ridges and plates, often so thick that it is often fire resistant and resistant to damage from burning. Bur oak may have terminal buds that include small hairs and resemble bear claws.

The fruit of the bur oak is an acorn with a large cap that features a hairy fringe forming a burr along the outside edge. The acorns vary in size, but average one inch in length, and the cap covers half to two thirds of the acorn.

Bur oaks, which grow to 70-80 feet tall and up to five feet wide, are common in both bottomlands and prairie regions, and can tolerate many different sites. Bur oaks can be found in nearly any county and any habitat type in Indiana. The natural range of bur oak is the eastern Great Plains from the Dakotas to Ohio to the eastern Appalachians, except through the southeastern United States. The range also extends into southern Canada.

Lumber from the white oak group, which includes bur oak, is among the heaviest next to hickory, weighing in at 45 pounds per cubic foot. It is very resistant to decay and is one of the best woods for steam bending. Bur oak, however, is somewhat weaker than other species in the white oak group.

 

For full article with additional photos view: Intro to Trees of Indiana: Bur Oak

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: Bur Oak
ID That Tree: White Oak Group
ID That Tree: Alternate Leaf Arrangement – Honey Locust/Bur Oak
Hardwood Lumber and Veneer Series: White Oak Group
Morton Arboretum: Bur Oak
Fifty Trees of the Midwest app for the iPhone, The Education Store
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
Bur Oak, Native Trees of Indiana River Walk, Purdue-Fort Wayne

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

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


Posted on November 3rd, 2022 in Forestry, Forests and Street Trees, Woodlands | No Comments »

The White Oak Initiative – Landowners for Oaks series is now available! This series, made up of 11 publications, is geared toward landowners engaged in upland oak management with a focus on white oak. Three of the publications provide information on the importance of oaks, their biology, and an overview of common management practices to enhance oak regeneration and growth. Eight publications provide landowners with basic information on common upland oak species, how to identify them and important management and utilization information. All factsheets in the series are available for free download at forestry.ca.uky.edu/woi.

Landowners for Oaks Series:White Oak Initiative website

Landowners Guide to Identification and Characteristics Series:

University of Kentucky Department of Forestry & Natural Resources/Extension authors:

Mike Saunders, associate professor of silviculture for Purdue Forestry & Natural Resources, continues adding his expertise with the white oak publications. “Personally, I think these are great resources for enlightening the public regarding the serious concerns natural resource managers have regarding the future of oak-hickory forests in the eastern U.S. They set a great tone in describing a complex issue. The impacts from the decades-long, persistent lack of oak regeneration are not easy for most to understand. For example, one may look up and see all the mature, large trees and think “hey, this is a healthy forest”. But the true future of the forest is at their feet, and whether they see it or their grandkids see it, that future is not great. There will be a dramatic shift to maple-dominance in our forests, something that will have profound, and potentially negative, impacts on all the values we associate with the forest (wildlife, water, recreation and timber),” states Dr. Saunders.

The White Oak Initiative is a diverse coalition of partners committed to the long-term sustainability of America’s white oak forests as well as the economic, social and environmental benefits they provide.

Resources:
Sustaining Our Oak-Hickory Forests – Hardwood Ecosystem Experiment, The Education Store
“The Nature of Oaks” Webinar With Author Doug Tallamy, Indiana Forestry & Woodland Owners Assocaition
Indiana Forestry and Wildlife: The Hardwood Ecosystem Experiment, The Education Store
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
Indiana Woodland Steward, promoting wise use of Indiana’s forest resources

Diana Evans, Extension and Web Communication Specialist
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.

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 introduce the red mulberry or Morus rubra.Drawing of red mulberry leaves

Red mulberry has variable leaves, which can come without lobes (entire) or with two (mitten), three or even five lobes. Regardless of shape, the leaves have serrated margins and pointed tips and are arranged alternately on the twigs. The topside of the dark green leaves is sandpapery to the touch and has a matte or flat finish. The dark green leaves turn a golden yellow in the fall.

Basswood has leaves similar to the unlobed variety of red mulberry, but those leaves are smooth to the touch and have finely toothed margins. White mulberry, which is not native to Indiana, also has similar leaves to its cousin red mulberry, but those leaves are typically bright green and smooth, have more rounded teeth on the margins and feature a shinier upper leaf surface.

The bark of red mulberry is gray or brown in color with long flaky ridges, but may show some orange or tan peeking through the fissures in the bark.

The fruit of red mulberry, which hangs individually only the twig, resembles a small blackberry, with a dark purple or almost black color when ripe, that is favored by both birds and humans. Mulberry fruit is typically produced from mid-June to July.

Red mulberry, which is often found under the canopy of other hardwood trees in moist areas such as river bottoms as well as along wooded slopes, wood’s edges and shady roadways, are typically small understory trees, but can grow between 40 and 60 feet tall. Red mulberries are becoming less common on the landscape than the invasive white mulberry, but can be found growing throughout the eastern United States.

The Morton Arboretum warns that red mulberry is susceptible to a variety of pests, including leaf spots, witches brooms, canker diseases, powdery mildew, spider mites and scale insects.

For full article with additional photos view: Intro to Trees of Indiana: Red Mulberry

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:
FNR Know Your Tree Series: Red and White Mulberry in Indiana
Morton Arboretum: Red Mulberry
Red Mulberry, Native Trees of Indiana River Walk, Purdue Fort Wayne
Fifty Trees of the Midwest app for the iPhone, The Education Store
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, Sustaining Hardwood Extension Specialist
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.

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.drawing of red maple

This week, we introduce the red maple or Acer rubrum.

Red maple has simple three to five-lobed leaves with relatively shallow, v-shaped divisions between the lobes. The oppositely held leaves may resemble sugar maple but the V shaped shallow divisions stand in contrast to sugar maple’s deep u-shaped sinuses. In the early spring, it is one of the earliest native trees to flower, producing clusters of reddish flowers as well as reddish colored pairs of winged seeds/fruit. In the fall, foliage typically turns a bright red to maroon color.

The bark is gray and smooth in young trees and may become flaky in older trees.

Red maple, which is a popular ornamental and street tree selection, is one of Indiana’s soft maples alongside silver maple. It also can be found in Indiana woodlands in both moist and dry sites and in bottomlands and uplands.

Red maple, grow 50 to 80 feet tall and are found growing throughout the eastern United States including the coastal regions.

The Morton Arboretum warns that red maple was display chlorosis symptoms of pale green leaves with dark green veins in high pH soil and drought conditions. The species also does not tolerate heavy pollution.

For full article with additional photos view: Intro to Trees of Indiana: Red Maple

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:
Hardwoods of the Central Midwest: Soft Maple
Hardwood Lumber and Veneer Series, The Education Store: Soft Maple
Morton Arboretum: Red Maple
Red Maple, Native Trees of Indiana River Walk, Purdue Fort Wayne
Fifty Trees of the Midwest app for the iPhone, The Education Store
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, Sustaining Hardwood Extension Specialist
Purdue University Department of Forestry and Natural Resources


Posted on October 3rd, 2022 in Forestry, Forests and Street Trees | No Comments »

Trees with colored leaves.WANE 15 Fort Wayne News & Weather interviews Dr. Jingjing Liang, associate professor of quantitative forest ecology from Purdue Forestry and Natural Resources, to ask the expert about when to expect fall leaves. Dr. Liang explains in WANE 15 video that if local forecast projections are correct with warmer temperatures and with little rain, we may have fall color earlier this year with leaves changing in the middle of October. Dr. Liang goes on to explain that with a reduction in solar energy and lower temperatures it will cause trees to produce less chlorophyll.

View full article, When to expect fall leaves this year written by Aaron Organ, for more information about why the green leaves turn to vibrant red, yellow and orange colors.

Check out our Got Nature blog “Why do Our Trees Go From Green Leaves to Different Colors?” which includes video Fall Color Pigments by Lenny Farlee, extension forester.

Dr. Jingjing LiangOther Resources:
Why Fall Color is Sometimes a Dud, Purdue Landscape Report
Forest Migration Plays a Role in Fall Foliage Colors, Purdue College of Agricutlure News
U.S. Forest Service Fall Colors, Forest Service, U.S. Department of Agriculture
ID That Tree Fall Color: Sugar Maple, Purdue Extension – Forestry and Natural Resources YouTube Channel, ID That Tree Playlist
ID That Tree Fall Color Edition: Black Gum, Purdue Extension – FNR YouTube Channel, ID That Tree Playlist
Autumn Highlights Tour – South Campus, Purdue Arboretum Explorer
Why Leaves Change Color – the Physiological Basis, The Education Store, Purdue Extension resource center
Subscribe, Purdue Extension-Forestry and Natural Resources YouTube Channel

Diana Evans, Extension and Web Communication Specialist
Purdue University Department of Forestry and Natural Resources


Purdue Landscape Report, Why are the Japanese beetles running late this year?: Nothing heralds summer like the hum of Japanese beetles ravenously descending on a flower garden. Cool weather this spring has slowed emergence of adults from the soil. Heavy spring rains early followed by relatively drier weather in late June, may have trapped adult Japanese beetles under a crusty layer of hardened soil. Due to their large numbers in many parts of Indiana last year, they are very likely just waiting for a good rain to soften the surface, so they can dig themselves into the light of day and on to your flowers. So, if we get a little more rain by the time this article comes out, we are likely to be awash in adult beetles.

Adult Japanese beetles feeding on leaves and flowers of oak leaf hydrangea, Purdue Landscape Report.Weather is only part of what makes Japanese beetles predictably unpredictable. Beneficial organisms including fungi, microsporidia, and parasitic wasps also act different life stages of Japanese beetles. Japanese beetles have been the target of several national programs to release these beneficial organisms to reduce beetle populations. Favorable conditions for these beneficials can help reduce the local abundance of grubs and beetles.

Although killing grubs will reduce the number of beetles, the small size of lawns and the long flight range of makes it unlikely for your grub control program to reduce defoliation.  In experiments conducted in my lab over 20 years ago, we found adult beetles can easily fly a kilometer (0.66 miles) in a single day.  With adults living for several weeks, it is easy to image beetles traveling long distances from untreated lawns to plants on your property.

Life cycle of Japanese beetles: As the weather warms in the spring larvae (aka white grubs) move closer to the surface and begin feeding on turf roots.  In May they enter a pupal stage and stop feeding.  In June they typically emerge from the soil as adults.  Adults fly in summer when they feed on flowers and leaves.   In late July and early August adults lay eggs into the turfgrass.  White grubs hatch from eggs and feed on the roots until frost when the larvae begin dig deeper into the soil to avoid killing temperatures.

To find out what you can do about Japanese beetles and view photos view: Why are the Japanese beetles running late this year?

Resources:
Report Invasive
Invasive Insects, Got Nature?
Invasive Species, Playlist, Purdue Extension – FNR YouTube Channel
Indiana Department of Entomology and Plant Pathology
Spotted lanternfly: Everything You Need to Know in 30 Minutes, Video, Emerald Ash Borer University
Emerald Ash Borer, EAB Information Network
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
What are invasive species and why should I care?, Got Nature? Blog, Purdue Extension – Forestry and Natural Resources
Pest Management, The Education Store

Cliff Sadof, Professor Entomology/Extension Fellow
Purdue Entomology


Purdue Landscape Report, What is Happening to the Weeping Willows?: While recent temperatures have been moderate in many parts of the state, rainfall has been lacking. (See The Annual Drought Article). There are chasms in the clay of my backyard that will swallow my kids and dogs whole. While I am not truly worried about the safety of my smaller family members, a lot of the plants that are not in shade are stressed. At the Purdue Plant and Pest Diagnostic Laboratory, we have received quite a few calls, emails, and samples about trees in decline. Trees that are already stressed, infected by a pathogen, or are infested by wood-boring insects will be showing their true colors in these drought conditions: chlorosis, leaf loss, and limb dieback.
Willow showing yellowing of older leaves on lower branches.

Weeping willow tree showing yellowing of older leaves on lower branches, PPDL.This month, one group of trees limps along to the top of our list of plants under stress due to lack of water: Willows. Salix spp. are not great landscape trees in general unless planted in locations that retain water. While they grow quickly and can appear beautiful for a number of years, when the soil becomes dry, these trees can very quickly develop limb dieback or cankers. In many cases, cankers become more obvious during these periods of stress because they were already present before the drought stress occurs. Damaged limbs die faster and multiple species of canker-causing fungi have been found to move faster in drought stressed wood of some tree species. We have found the fungi Cytospora, Botryosphaeria, and Colletotrichum associated with cankers on recent branch submissions to the lab.

Thinning of the branches, cracks/splits in the bark, and black lesions on green stems can indicate the presence of a canker which should be pruned out and destroyed, if at all possible. Supplemental irrigation may be required during dry spells for trees that are water loving or, at least, drought intolerant. Fungicides are not effective for these fungal pathogens that live inside the wood, where fungicides can’t penetrate. In most cases larger willow trees will not die because of these problems but they may suffer significant branch loss and may become disfigured. In some cases very young trees or shrub type willows may be killed.

For full article and photos view: What is Happening to the Weeping Willows?

Resources:
Summer Tree Care, Purdue Landscape Report
Drought? Don’t Forget the Trees!, The Education Store, Purdue Extension resource center
Extreme Heat, Purdue Extension – IN-PREPared
Drought Information​, Indiana Department of Natural Resources
Planting Your Tree Part 1: Choosing Your Tree, Purdue Extension YouTube Channel
Tree Selection for the “Un-natural” Environment, 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

John Bonkowski, Plant Disease Diagnostician
Plant and Pest Diagnositc Laboratory


Many homeowners are finding their trees with dry and wilted leaves. In this video, Lindsey Purcell, Indiana Arborist Association chapter administrator, talks about the importance of watering your trees and how to do so effectively.

Extreme heat can have a major impact on tree health and survival. Water is the most limiting ecological resource for a tree, and without adequate moisture, decline and death are imminent. It reduces carbohydrate production, significantly lowering energy reserves and production of defense chemicals in the tree. Check out this publication titled Drought? Don’t Forget the Trees! to learn what to look for for any weakening issues including pests that like the dry conditions.

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:
Summer Tree Care, Purdue Landscape Report
Drought? Don’t Forget the Trees!, The Education Store, Purdue Extension resource center
Extreme Heat, Purdue Extension – IN-PREPared
Drought Information​, Indiana Department of Natural Resources
Planting Your Tree Part 1: Choosing Your Tree, Purdue Extension YouTube Channel
Tree Selection for the “Un-natural” Environment, 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

Lindsey Purcell, Chapter Administrator & Master Arborist
Indiana Arborist Association

Ben McCallister, Urban Forestry Specialist
Purdue Forestry & Natural Resources


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