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The time is now to start protecting your trees!  Now that your ears are perked up, let’s talk a bit about Southwest injury on trees.

Bark cracking (Fig.1) is a phenomenon that occurs in many species of trees and can have many causes. One of the most common types of bark cracking is termed Southwest injury. Southwest injury occurs during the winter months on the lower section of the trunk on the southwest side. This happens when there is a sudden temperature drop, for example, the sun going behind a cloud during the winter. The freeze-thaw cycle happens very quickly when there is a change from very warm to cold conditions, which results in a crack. If there is a snow pack, the reflection of sunlight on the bark will actually increase the temperature in the bark.

Usually Southwest injury occurs on thin-barked trees, such as Acer spp., Cercis spp., Malus spp., and many others (Fig. 3). A thin-barked tree lacks the amount of cork cells in thicker-barked trees, thus allowing the vascular tissue to be located very close to the bark.  Thick bark trees tend to be more resistant to cracking due to a greater lag in the freeze/thaw cycle. Trees that are under stress due to environmental factors, herbicide injury, and/or insect and disease are more susceptible to cracking.

No matter the initial cause of the crack, the common denominator of a crack in the bark is a pre-set wound. The freeze-thaw cycle during the cold months causes the point of injury to expand and contract. Like with your vehicle windshield, a small point of injury in bark will expand and contract due to sudden heating or cooling, thus causing a large crack.

Any type of cracking that occurs, originates from a point of injury, such as a pruning or other mechanical injury. These are horizontal cracks that can range from <1” to the entire length of the trunk, though are usually localized near the bottom of the trunk (Fig. 4).

Once trees are greater than about four inch caliper, the likelihood of Southwest injury is diminished.  On trees four inches or less, tree guards (also called tree wraps) should be installed over each trunk.

White tree guards may help prevent this from occurring due to the reflection of the sun, preventing overheating on the bottom of the trunk (Fig. 5) In order to prevent cracking, try to prevent any type of mechanical damage that could cause cracking in the winter. Bark cracks become visible most often during the late winter/early spring. Tree guards should be removed in the spring, because the guards become a problem with disease due to moisture within the guard.

In some circumstances a healthy plant may heal, partitioning off the damaged area, but the bark on a plant under stress, due to drought, herbicide damage, etc., may last the entire life of the tree.

For full article, check out the Landscape Report

Resources
Trees and Storms: Understanding Damage, Risk and Recovery – Got Nature? Blog, Purdue Extension – FNR
Pruning Ornamental Trees and Shrubs, The Education Store
Why Hire an Arborist, The Education Store
Why Is My Tree Dying? – Got Nature? Blog, Purdue Extension – Forestry and Natural Resources
Weeping Cherry Trees Appear to be Damaged or Dead. Was This Past Winter Hard on These Types of Trees?, Got Nature? Blog

Lindsey Purcell, Urban Forestry Specialist
Purdue Forestry and Natural Resources

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The DNR Division of Entomology & Plant Pathology has discovered that a shipment of boxwood plants infected with boxwood blight was shipped to Indiana in May.

This is important because boxwood blight (Calonectria pseudonaviculata) is a fungal disease that infests members of the popular Buxaceae family, and is often transported through the nursery trade. Hosts include Buxus (boxwood), Pachysandra (Japanese spurge) and Sarcococca (sweetbox).

In total, 23 stores in Indiana received infected material in early spring (particularly “Graham Blandy” cultivar), and it’s possible that members of the public inadvertently purchased some plants.

The fungus, which can lay dormant in drier conditions, can be found on all above-ground portions of the plant and presents itself as dark leaf spots. It causes rapid defoliation, which typically starts on the bottom of the plant and moves toward the top. This fungal pathogen can move through sporulation  in water and from dropped leaves. As a result, infection can spread to surrounding plants from a single infected plant.

If you suspect one of your plants shows signs and symptoms of boxwood blight, please call (866) NO EXOTIC (866-663-9684) use the information at dnr.IN.gov/entomolo.

For more information on this pathogen see the following link extension.purdue.edu/extmedia/BP/BP-203-W.pdf

A DNR inspector found the plants at a national chain home and garden store in early October. The shipment originated at a nursery in Oregon. It was also sent to stores in 11 other states.

Upon confirmation of boxwood blight on these plants by the Purdue Plant and Pest Diagnostic Lab, the DNR required that the chain remove all boxwood from their shelves for disposal and that the stores mitigate the area through disinfection to ensure that the pathogen is no longer present and able to infect further shipments of plants.

The DNR is currently surveying for boxwood blight in Indiana. To date, the DNR has not found the pathogen, except for a few interceptions like this one.

To view all DNR news releases, please see dnr.IN.gov.

Resources:
Boxwood Blight Found in Indiana, full Landscape Report
Boxwood Blight, The Education Store, Purdue Resources

Tom Creswell, Clinical Engagement Associate Professor
Purdue Botany and Plant Pathology

Lindsey Purcell, Urban Forestry Specialist
Purdue Forestry and Natural Resources

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It all starts with providing some supplemental nutrition for small to medium-aged trees in the late fall when trees go into a state of dormancy. This is when trees stop active growth and begin to form terminal buds, drop leaves and develop cold resistance.  Adding fertilizer to trees too early in the season can push new growth which will be prone to winter damage.

A fertilization program is used to maintain trees in a vigorous condition and to improve their immune system against pests. Fertilizing trees refers to the practice of adding supplemental nutrients (chemical elements) required for normal growth and development. However, you really can’t “feed” a tree, since trees are autotrophs. They use nutrients to feed themselves by making sugar in the leaves through photosynthesis.

Nitrogen (N), phosphorus (P), and potassium (K) are plant nutrients needed in the largest quantity and these are most commonly applied as a complete fertilizer. However, the addition of any soil nutrient is recommended only if soil or plant foliage tests indicate a deficiency. For trees and shrubs in most of Indiana, the two most common causes of nutrient problems are high pH (alkaline) soils, which can lead to chronic deficiencies of nutrients in some tree species, such as red maple and pin oak, and nitrogen-deficient soils. Typical symptoms include yellowing chlorotic leaves and reduced growth and smaller leaf size.

Trees in natural settings get nutrients from the air, organic matter, nutrient cycling, and microbial activity. In many cases, supplemental nutrition is not necessary in fertile soils which have enough nutrients in the proper amounts to support healthy growth, especially on established trees, but in the urban and suburban environment, often a little assistance is needed. The more challenging urban environment provides less opportunity for healthy growth due to poor, fragmented soils, reduced microbial activity and compaction. Trees needing fertilization to stimulate growth include those exhibiting the symptoms of pale green, undersized leaves, chlorosis, reduced growth rates and those in decline resulting from insect attacks or disease problems. Also, turf can be a serious contender for nutrients and trees surround by turf benefit from additional nitrogen applications every couple of years.

Trees which should not be fertilized include newly planted trees in the current year and those with root damage from recent trenching, construction or other disturbance. The root systems of these plants will need to re-establish before fertilizers are applied with cultural practices such as supplemental moisture and mulch. Older, established trees do not need to be fertilized every year and may never need supplemental feeding. In fact, serious pest problems can result on over-fertilized trees. Research indicates that young deciduous trees benefit from additional nitrogen in low-analysis, slow release forms.  Conifers require less fertilization and are genetically adapted to low-nutrient soils.

For more information on how and when to fertilize trees, refer to HO-140-W, Fertilizing Woody Plants from the Purdue Extension Education Store.

Article shared by: The Landscape Report, Start Preparing Trees for Winter and Next Year.

Resources:
Trees and Storms: Understanding Damage, Risk and Recovery – Got Nature? Blog, Purdue Extension – FNR
Tree Risk Management – Got Nature? Blog, Purdue Extension – FNR
Fertilizing Woody Plants, The Education Store

Lindsey Purcell, Urban Forestry Specialist
Purdue Forestry and Natural Resources

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A lepidopterist from the Florida Museum of Natural History has made a shocking discovery regarding moth behavior. Dr. Andrei Sourakov noted a dozen or so black Idia moths resting inside a hollow tree. This species, and most other moth species is typically solitary as opposed to social species like bees and ants. He went on to discover groups of as many as 400 individuals each oriented facing north (the top of the tree) and tucked away form the light. Both males and females rested quietly, each spaced away form the first reported example of moths gathering in a large group on a daily basis, similar to the roosting observed in bats, a primary predator of moths.

Dr. Sourakov also noted that the moths do not have a preference for tree type as they have been observed in sweetgum (Liquidambar styraciflua) and southern red oak (Quercus falcata) trees in Florida. It is suspected that a single moth finds a hollow tree and releases sex hormones to inform nearby moths where to assemble. As no mating has been observed at the location, these moths respond to the pheromone lure but do not act on a any perceived sexual stimulus.

References:
Andrei Sourakov. Mass aggregations of Idia moths (Lepidoptera: Erebidae) inside hollow trees in Florida. Tropical Lepidoptera Research, 2018 DOI: 10.5281/zenodo.1309644

Online Article: Florida Museum of Natural History. “Hollow trees host massive moth slumber parties.” ScienceDaily. ScienceDaily, 28 July 2018.

Resources:
Hardwood Ecosystem Experiment (HEE) Highlights: Moths, video, Purdue Extension – Forestry & Natural Resources Got Nature? Blog
Gypsy Moth (Spongy Moth) website, Purdue Extension-Entomology
Spongy Moth – Indiana Department of Natural Resources
The Gypsy Moth in Indiana – The Education Store, Purdue Extension resource center

Shaneka Lawson, USDA Forest Service/HTIRC Research Plant Physiologist/Adjunct Assistant Professor
Purdue University Department of Forestry and Natural Resources

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Snake fungal disease (SFD), caused by the fungus Ophidiomyces ophiodiicola, is an emerging pathogen of snakes identified in more than 15 genera of captive and free-ranging snakes in 21 states.

SFD is not considered a risk to people.

Some infected snakes show no symptoms. Others develop facial swelling and disfigurement, skin and scale lesions and internal lesions. For some snakes, the disease is fatal.

The fungus can persist in the soil. The route of transmission is unknown, but may occur through contact with soil, other infected snakes, or from mother to offspring.

SFD in Indiana
Researchers from the University of Illinois first identified SFD in Indiana in late 2017 during a surveillance project for the disease.

The researchers swabbed the skin of 53 snakes from 10 Indiana counties. Of those, 13 tested positive for the fungus. Two of those 13 snakes had visible lesions. Species that tested positive included the northern water snake (Nerodia sipedon), racer (Coluber constrictor), milk snake (Lampropeltis triangulum) and queen snake (Regina septemvittata).

The surveillance project was funded by the Indiana Department of Natural Resources State Wildlife Grant T7R22.

Why monitoring SFD is important
Snakes are important predators and play a critical role in maintaining a balanced ecosystem. Having healthy snake populations in Indiana is necessary to keep rodent populations in check.

Resources:
Snakes and Lizards of Indiana, The Education Store, Purdue Extension’s resource center
Snakes of the Central and Northeastern United States, The Education Store

Indiana Department of Natural Resources (IDNR)

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This summer the Nature of Teaching team partnered with the Maine Department of Inland Fisheries and Wildlife (IFW) to host teacher workshops at the Maine IFW headquarters in Gray and the Fields Audubon Center in Holden, ME. The team worked together to organize and facilitate these two two-day workshops to bring Nature of Teaching educational resources to 47 K-12 public and private school educators, administrators, and environmental center staff.

During these workshops, funded by an FNR small grant and an IBAT grant, the Purdue/Maine team, as well as guest speakers from Project Wild, took turns presenting information on wildlife, health and wellness, and food waste. After each presentation, teachers walked through corresponding lesson activities that they could use with their students. Then they were given the opportunity to collaborate with other educators in their grade levels. Workshop participants walked away with a binder of resources and were given the opportunity to pursue stipends by completing a post-workshop survey and submitting student pre/post assessment data.

 

The Purdue/Maine partnership has been beneficial in bringing the Nature of Teaching resources to Maine educators while incorporating local knowledge and expertise and increasing awareness of resources provided by the Maine IFW. The team is currently developing a Mammals of Maine publication to accompany the Mammals of Indiana publication on the Nature of Teaching website, and planning for at least one workshop in Maine next year.

To learn more about the Nature of Teaching, visit our website at www.purdue.edu/nature, connect with us on Facebook at https://www.facebook.com/NatureofTeaching/, or contact Rebecca Busse at busser@purdue.edu.

Resources:
Nature of Teaching Lesson Plan: Conservation Biology, Got Nature? Blog
The Nature of Teaching – Purdue Extension

Rebecca Busse, Nature of Teaching Program Coordinator
Purdue Forestry and Natural Resources

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A recent study at the University of British Columbia noted that a single tree along an urban street can help alleviate winds, shade pedestrians, and decrease wind pressure on nearby buildings. For both homes and businesses, the presence of trees can help decrease costs associated with maintaining indoor temperatures.

Researchers used remote sensing technology to create intricately detailed computer models of a neighborhood that included each tree, garden, and structure. The models were able to elucidate how various scenarios (no trees, bare trees, full-leaf trees) influence airflow, thermal patterns, and overall radiant heating and cooling throughout the streets of the neighborhood. Resultant data indicated trees at various stages can decrease wind speeds by as much as a factor of two. For example, a strong 30km/h wind could be reduced to a comfortable 15km/h breeze.  The results also showed trees reduced the strain caused by wind pressure on building spaced closely together and farther apart. Close examination of the data indicated wind pressure causes up to a third of the costs associated with energy consumption and increased costs up to 10% in winter and 15% in summer. Using data gleaned from over a decade of measurements (from a monitored wind tower), they discovered even leafless trees are beneficial in winter months to regulate air flow and wind pressure on buildings.

This modeling effort represents the first of its kind to simulate actual neighborhood conditions using an existing neighborhood recreated in great detail as a model. Further work of this kind can be used to predict storm effects on structures and pedestrian movement. These data can assist engineers and city planners in the creation and layout of buildings, streets, and greenery while limiting energy losses and help evaluate proposed effects of weather forecasts throughout the neighborhood.

References:
M.G. Giometto, A. Christen, P.E. Egli, M.F. Schid, R.T. Tooke, N.C. Coops, M.B. Parlage. 2017. Effects of trees on mean wind, turbulence and momentum exchange within and above a real urban environment. Advances in Water Resources, 106: 154 DOI: 10.1016/j.advwatres.2017.06.018

University of British Columbia. Trees can make or break city weather. Science Daily, 26 July 2017.

Resources:
Tree Selection for the “Un-natural” Environment, The Education Store – Purdue Extension’s resource center
Planting Your Tree Part 1: Choosing Your Tree (Youtube video),  Purdue Extension-FNR
Tree Installation: Process and Practices , The Education Store
Tree Planting Part 2: Planting a Tree (Youtube video), Purdue Extension-FNR
Top 5 List for Tree Selection and Planting, Got Nature?, Purdue Extension-FNR
Indiana’s Urban Woodlots, The Education Store

Shaneka Lawson, USDA Forest Service/HTIRC Research Plant Physiologist/Adjunct Assistant Professor
Purdue University Department of Forestry and Natural Resources

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People have been catching wild turtles and selling them as pets, leading to many species becoming endangered.  This is very dangerous for the health and survival of the turtle as well as being highly illegal in Indiana. We highly discourage you from taking turtles from their natural habitat and turning them into pets (or any animal for that matter). Here’s a list of reasons why it is not good to make a pet out of a wild turtle and what you can do if you see any turtle miss handling and turtle wrong doing.

Turtles DO NOT make good pets!

Reasons why turtles aren’t good pets:

• Turtles require time and money for proper care, and some species can live up to 50 years.
• Pet turtles do not like to be held and are loners; therefore, they can become boring pets for children.
• Turtles are cold-blooded and need a source of heat. They also require an ultraviolet light for proper growth and health.
  • Without this special light, many health issues arise such as metabolic bone disease.
• It is very important to know what kind of species you want and the care it needs before you acquire a pet turtle. Many need special food and tanks.
  • Each species has different feeding requirements, with some being strictly carnivores or herbivores. Map turtles, for example, have restricted diets that must include snails, aquatic insects and crayfish. Some species of aquatic turtles, such as the red-eared slider, map turtle and soft-shell, grow up to 12 inches long, requiring a large tank for swimming and basking.
• Land turtles need a large pen, with sufficient substrate, properly sized water bowl, a hide area, as well as heat. Some require more humidity than others.
• If you no longer want your pet turtle, you cannot release into the wild because it is not likely to survive.
  • It will have to find its own food, deal with the elements and deal with predators.
  • These once-captive turtles are also likely to transmit diseases to wild turtle populations.
• Turtles can carry salmonella bacteria.
  • The Centers for Disease Control and Prevention recommend that children, pregnant women, and persons with compromised immune systems avoid contact with reptiles to avoid getting Salmonella.
  • The DNR does not encourage the keeping of turtles as pets, but does allow it if the turtle species is obtained legally with a hunting or fishing license.

 

It is illegal to sell wild turtles

Many native, wild-caught turtles are still sold as pets, even though this practice is illegal in Indiana. The collection of wild turtles has caused many species to become endangered, especially when combined with habitat loss, water pollution and predators. Predators such as raccoons eat a large number of turtle eggs each year, and some species do not even breed until they are several years old, meaning that it can take many years for a population to become established. You can help protect Indiana’s turtles by helping to preserve turtle habitat, especially wetlands, through local conservation organizations or the Indiana Nongame and Endangered Wildlife Program.

Help our endangered turtle species and report any wrong handling, contact DNR Customer Service Center.

For the full article, see Turtles As Pets, Indiana Department of Natural Resources.

Resources:
Turtles of Indiana, The Education Store, Purdue Extension’s resource center
Reptile and Amphibian Regulations, Indiana Department of Natural Resources
Eastern Box Turtle Information, Indiana Department of Natural Resources

Indiana Department of Natural Resources (IDNR)

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The American persimmon tree’s scientific name, Diospyros virginiana, is loosely interpreted “divine fruit” or “fruit of the gods” of Virginia. If you have tasted a ripe persimmon on a crisp fall day, you might agree with that assessment. Several persimmon tree species are found in both the new and old world and have been used for food and wood products for centuries. Our American persimmon is native to the southern half of Indiana but can survive in the northern half of the state as well.

The ripe fruit is famous for the sweet orange pulp used in puddings, cookies and candies. If you are unlucky enough to eat a persimmon that has not yet ripened, your opinion of its eating quality will be quite different. Unripe persimmons have a high tannin content that makes the fruit very astringent – I describe it as feeling like your head is shrinking while simultaneously trying to expel a glue ball from your mouth! Most dedicated persimmon collectors wait for the fruit to become soft and fall from the tree before collecting to avoid this unpleasant experience. Contrary to popular belief, the fruit does not have to experience a frost to ripen. Persimmon fruit normally ripen in September and October, but some trees hold fruit well into winter.

A warning to those tempted to over-indulge in persimmon fruit: the tannin in the unripened fruit can combine with other stomach contents to form what is called a phytobezoar, a sort of gooey food ball that can become quite hard. One patient had eaten over two pounds of persimmons every day for over 40 years. Surgery is often required to remove bezoars, but a recent study indicated Coca-Cola could be used to chemically shrink or eliminate the diospyrobezoar. There is very little risk to those infrequently eating ripe persimmons.

Persimmon is related to ebony and has extremely hard wood once commonly used for golf clubs when “woods” where actually made of wood. The heartwood of persimmon can be black, like ebony, but significant dark heartwood formation may not occur until the tree is quite old. Persimmon is a medium-sized tree here in Indiana but can be over 100 feet tall in the bottomland forests of the Southern U.S. Where I grew up in Southern Indiana, my family ritual in the fall was to go to Brown County State Park and pick up persimmons, separate the tasty pulp from the skin and seeds and freeze the pulp for use in persimmon pudding and candy over the holidays. We might also collect some black walnuts or hickory nuts to include in the candy. We had to be diligent, as the opossums, raccoons and deer liked persimmon as much as we did.

In addition to use for food, persimmon has some folk tradition related to winter weather forecasting. It was thought the shape of the embryo in the seed could predict the winter weather: a spoon shape indicated deep snow, a knife would indicate icy cutting winds and a fork meant it would be mild with plenty to eat until spring. I collected a few seeds from trees here on the West Lafayette campus and split them open to see what the tree wants to tell me – looks like a spoon to me, but you can make your own predictions.

The Indiana DNR Division of Forestry Nursery sells American persimmon seedlings. You can also find selections for fruit production being sold commercially, along with several Asian persimmon varieties. Male and female flowers are normally formed on separate trees, so plant several to get good pollination.

The following site has a wealth of information on persimmon, including several recipes and locations to buy pulp and seedlings, as well as natural and cultural history including the annual Persimmon Festival in Mitchell, Indiana:
http://www.persimmonpudding.com/.

Resources:
Persimmons, The Education Store, Purdue Extension resource center
Resources and Assistance Available for Planting Hardwood Seedlings, The Education Store
Tree Installation: Process and Practices, The Education Store
Tree Planting Part 1: Choosing a Tree, video, The Education Store

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