Got Nature? Blog

Purdue Landscape Report: Hot, dry summers are not that unusual in the Midwest, but 2020’s hot dry spell started considerably earlier than usual, before summer even officially began! To make it a triple whammy, the hard freeze in early May caused some landscape plants to burn up more stored carbohydrate reserves to produce a second round of foliage.

(Figure 2) July Heat Map

(Figure 2) July Heat Map

I’m sure I don’t have to point out that most of Indiana is currently experiencing abnormally hot, dry conditions. Although recent rains have brought relief to some areas, any respite is sure to be temporary. Seasonal thunderstorms may deluge some landscapes with water while other areas, even those close by, may stay fairly dry. Much of the area has experienced highs in the upper 80’s to over 90º F over the past month.

Leaf scorch on trees and shrubs, appearing as a browning along the edges of the leaves, is very common in dry summers. While minor cases of leaf scorch are not very harmful, prolonged lack of moisture can spell disaster for landscape plants.

Leaf Scorch on Lilac

Leaf Scorch on Lilac

Hydrangea wilting

Hydrangea wilting

Young and newly established plants are most susceptible to the dry conditions, but even established plants may reach a critical point during prolonged drought. If the heat and drought continue this summer, branch dieback, combined with eventual root death, will make plants more susceptible to winter injury. Plants that were already under stress from other factors may succumb to severely dry soils.

The intense heat makes it difficult for plants to keep up with water and cooling requirements, even in areas where moisture is adequate. One of the ways that plants cool themselves is through transpiration, which allows water to evaporate from the foliage. Plant leaves have pores called stomata that can open and close to allow water vapor and gas exchange with the environment. During extreme heat and/or drought, stomata will nearly close, thus reducing transpiration and exchange of carbon dioxide and oxygen. The end result is seen as wilting foliage and leaf scorch. But not so obvious is that reduced water uptake and gas exchange also leads to reduced production of carbohydrates through photosynthesis and reduced uptake of soil nutrients, having longer term impact on plant health.

There is still plenty of summer yet to get through to see the further challenges ahead. Meanwhile, we can mitigate some of the stress by watering landscape plants as needed where feasible.

US Drought Monitor
Indiana – Purdue Rural Emergency Preparedness, Purdue Extension website
In Times of Drought, Indiana Yard and Garden, Purdue Consumer Horticulture
Drought? Don’t Forget the Trees, The Education Store, Purdue Extension resource center
Turfgrass Disease Profiles: Summer Patch, The Education Store
Iron Chlorosis of Trees and Shrubs, The Education Store

, Extension Consumer Horticulturist
Purdue University Department of Horticulture and Landscape Architecture

Posted on July 6th, 2020 in Disease, Drought, How To, Land Use, Plants, Webinar | No Comments »

Purdue Landscape Report: Don’t miss the opportunity to virtually attend the annual Purdue Turf and Landscape Field Day!  For the first time, we are offering cutting edge research and updated best management practices online.

WEST LAFAYETTE, Ind. — Green industry professionals from landscape firms, lawn care companies, golf courses, sports turf companies, garden centers and more are invited to the 2020 Turf and Landscape Virtual Field Day hosted by the Purdue University Department of Horticulture and Landscape Architecture and the Midwest Regional Turf Foundation.

While online this year, Indiana’s largest green industry field day will continue its tradition of providing high-quality education, turf and landscape research updates, product updates and networking opportunities for attendees.

The flexible online field day will be available for attendees for one week starting July 14. Purdue faculty and staff from the departments of Botany and Plant Pathology, Entomology, Horticulture and Landscape Architecture, and Forestry and Natural Resources will speak on important topics within the green industry and share information from research plots.  A live question and answer session with all of the speakers will be held on July 21.

Commercial pesticide and fertilizer applicators will receive continuing certification credits for attending.

The online field day will cost $30 for Midwest Regional Turf Foundation and Indiana Nursery and Landscape Association members or $50 for nonmembers. Discounted registration will be offered for groups with four or more registrants. Online registration is due by July 10. More information can be found on the Midwest Regional Turf Foundation website.

For any questions about the field day, please call or email Brooke Ponder at 765-494-8039 or

Turfgrass Weed Control for Professionals 2020 Edition – PDF, The Education Store, Purdue Extension resource center
Turfgrass Weed Control for Professionals 2020 Edition – Box of 25, The Education Store
Forest Improvement Handbook, The Education Store
Turfgrass Insect Management, The Education Store
Tree Planting Part 1: Choosing a Tree, Video, The Education Store
Purdue Turf Doctor app for Apple iOS, Apple App Store

Brooke Ponder, Turf Program & Event Coordinator
Purdue University Department of Horticulture and Landscape Architecture

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

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

Purdue Forestry & Natural Resources extension specialists gathered for a Facebook LIVE event held May 5th to answer questions on a wide range of topics from woodland management to wildlife habitat, ponds to invasive species and more.

Topics ranged from what to do about moles, voles and Canada geese causing damage in your yard, to how to pick the right tree for your landscape and how to measure the worth of your trees. The presentation also included segments on what to do about algae in your pond to how to know if you need to restock it as well as what to do about invasive plant species and how to protect your trees from deer damage.

Get advice from extension specialists Jarred Brooke, Lenny Farlee, Brian MacGowan, Lindsey Purcell, Rod Williams and Mitch Zischke in the video below.

If you have any further questions feel free to send your questions by submitting our Ask An Expert form.

Resources mentioned:
Purdue Extension – The Education Store
Purdue Report Invasive Species Website
Midwest Invasive Species Network Database
Find a Forester in Indiana
Improve My Property for Wildlife, Purdue Extension
Online Mole Program, Event May 14th, Purdue FNR Extension
Have you seen a hairless squirrel, Got Nature? Blog, Purdue FNR Extension
Stocking Fish, The Education Store, Purdue Extension Resource Center
Tree Selection for the “Un-natural” Environment, The Education Store
Selecting a Nuisance Control Operator, The Education Store
Forest Products Price Report (pdf), Indiana Department of Natural Resources (IDNR)
Indiana DNR Nuisance Goose Control Options (pdf), Indiana Department of Natural Resources (IDNR)
Turtles of Indiana, The Education Store
Salamanders of Indiana, The Education Store
Frogs and Toads of Indiana, The Education Store
Snakes and Lizards of Indiana, The Education Store
Aquatic Plant Management, The Education Store
Native Grasses, The Education Store
Preventing Deer Browsing on Trees/Shrubs, Video, Purdue Extension Youtube Channel

Brian MacGowan, Wildlife Extension Specialist
Purdue University, Department of Forestry and Natural Resources

Posted on September 4th, 2015 in Drought, Forestry | No Comments »

Trees in Times of Drought Video Water is the most limiting ecological resource for a tree, and without adequate moisture, decline and death are imminent. Drought can have a major impact on tree health and survival. It reduces carbohydrate production, significantly lowering energy reserves and production of defense chemicals in the tree.

Trees in a weakened state from drought are more susceptible to pests, which can further weaken the tree, and even kill part or all of it. Although there is nothing we can do to prevent drought, it is important to know what can be done to reduce long-term effects of prolonged dry conditions.

Urban Forestry Specialist Lindsey Purcell describes how homeowners can deal with drought-stressed trees in the short-term and long-term in his publication “Drought? Don’t Forget the Trees!” Purcell also provides insight on the state of Indiana’s drought-stressed trees and how to protect them in the video “Trees in Times of Drought​.”

Drought? Don’t Forget the Trees! The Education Store, Purdue Extension Resource Center
Trees in Times of Drought Video, Purdue Agriculture
Drought Information, Purdue Extension
The Drought . . . continues? Got Nature?
Drought Information​, Indiana Department of Natural Resources

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

Posted on August 20th, 2015 in Drought, Forestry, Urban Forestry | No Comments »

Indiana has experienced extreme weather over the last couple of years. Extreme heat, draught, cold, winds, you name it, we’ve dealt with it. Most recently, through June and July, Indiana has experienced record-breaking rainfall and flooding. These weather conditions can make it difficult for our surroundings, but it can also cause a lot of stress on our trees.

Maple Tree

Photo credit: Keith Robinson

Urban trees are more susceptible to weather-related injury because of their oftentimes compromised root systems. In forested areas, trees spread their roots out two to three times the length of the tree. This is important because roots are the tree’s way to receieve oxygen from the soil. This provides for a healthy defense system, giving the tree advantages like the ability to draw in moisture during dry spells and secrete fungi- and insect-repelling chemicals. In urban areas, roads and construction oftentimes sever roots or restrict where they can go, leaving the trees in a vulnerable state.

Our vulnerable urban trees are especially likely to be harmed by weather-induced stress. Symptoms like browning of leaves, dying branches and early coloration in the fall are all signs that a tree’s health is declining.

Keep an eye on your trees, and if you are concerned, use the Purdue Tree Doctor app​ or submit a sample to the Purdue Plant and Pest Diagnostic Lab as you seek best practices to care and protect your trees.

Purdue Experts: Tree Deaths Across Indiana May be Related to Weather Stress, Purdue Agriculture News
Drought? Don’t forget the trees! The Education Store, Purdue Resource Center
Plan Today For Tomorrow’s Flood, The Education Store
Community & Urban Forestry, Indiana Department of Natural Resources
The Root of the Problem, Northern Woodlands

Purdue University Agriculture News

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

B. Rosie Lerner, Extension Consumer Horticulture Architecture
Department of Horticulture and Landscape Architecture, Purdue University​

Posted on August 11th, 2014 in Drought, Forestry, How To, Plants | No Comments »

mulch at base of tree

Although fresh chips from tree pruning and removals look great for mulch and compost, there are some hidden issues. First, fresh wood chips can be very acidic (sometimes down around a pH of 4) which can be detrimental to plant growth. Also fresh chips have a high C:N (carbon to nitrogen ratio), and it must borrow nitrogen from the soil to help the decomposing process. So mixing the chips with the soil can actually reduce fertility for a while. Both of those can be problems for plants trying to grow in a bed mulched or mixed with fresh chips. Ideally, the newly ground chips should compost properly for a full year. If nitrogen fertilizer is added to the soil/mulch mix, it can speed up the process.

The effects of wood chips as mulch involve mainly the surface of the soil, which means it’s mainly shallow-rooted plants like perennial and annual flowers that would run into fresh wood chip trouble. This includes serious chlorosis and other health issues involving establishment and development. Deeper-rooted trees and shrubs are less likely to be affected as much; however, they are subject to the effects of the poor C:N ratio. I would suggest removing as much of the chips as possible, piling them for composting and replacing with proper soil for perennial growth unless you can wait for a full year to allow the decomposition cycle to be completed. This may help eliminate issues with new plants going into that location.

Mulching Conserves Soil Moisture, Department of Horticulture and Landscape Architecture
Growing Perennial Flowers, The Education Store (Search keywords to find the resources you need)
Collecting Soil Samples for Testing, The Education Store
Soil and Water Conservation Districts, Indiana State Department of Agriculture
Certified Soil Testing Laboratories, Purdue Department of Agronomy/Extension

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

Posted on March 4th, 2013 in Aquaculture/Fish, Drought, Forestry, Wildlife | No Comments »

Indiana farmers could be in for a warm and wet early spring when they head into the fields to plant their crops, the Indiana State Climate Office says. But they also could expect a return to drought in some parts of the state during the growing season.

Full article . . .​

Posted on November 30th, 2012 in Drought, Forestry | No Comments »

The Scientist
By Sabrina Richards | November 27, 2012

Using satellite data, researchers calculate that mountain pine beetle infestations raise summertime temperatures in British Columbia’s pine forests by 1 degree Celsius.

Pine beetle infestation increases the summertime temperatures of some Canadian forests by 1 degree Celsius—about the same impact as a forest fire—according to new findings published Sunday (November 25) in Nature Geoscience. The beetle populations, spurred into profusion by global warming, appear to be contributing to a temperature feedback loop, though it remains unclear how much the insects may affect weather patterns.

The results reinforce the conclusion that ecological disturbances like beetle infestations can have significant ecological impacts, said Allan Carroll, an insect ecologist at the University of British Columbia who did not participate in the research. “We have until very recently considered biotic disturbances a bit player [in climate change],” noted Carroll, who collaborated on a recent study showing that pine beetle outbreaks transform forests from carbon sinks into large carbon emitters. The current study confirms that pine beetles can have massive effects that set up “an uncomfortable feedback” wherein warming temperatures encourage more beetle damage, which in turn influences warming, Carroll noted.

Full Article . . .

H. Maness et al., “Summertime climate response to mountain pine beetle disturbance in British Columbia,” Nature Geoscience, doi:10.1038/ngeo1642, 2012.

Posted on November 6th, 2012 in Drought, Forestry | No Comments »

​Increased temperatures from climate change have been expected to speed decomposition of plant materials and the return of nitrogen to soils, making the soil more fertile for plants. But Jeff Dukes, an associate professor of forestry and natural resources at Purdue, found that the microbes responsible for returning nitrogen to soils react differently to a range of climate scenarios.

“More nitrogen being available is not something we can count on in all ecosystems,” said Dukes, whose findings were published in the journal Global Change Biology.

Full Article . . .

Posted on September 29th, 2012 in Drought, Forestry | No Comments »

​Now that the dreadfully hot and dry summer is behind us, we might be wondering what to expect for the fall and coming winter in Indiana.

A variable temperature and precipitation pattern is developing this fall with September so far a cool and wet month. Indiana average temperatures have run nearly two degrees below normal while precipitation has ranged from near normal in the northern third of the state to more than twice normal in central counties, according to the Indiana State Climate Office based at Purdue University.

Full Article . . .

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