Southeastern Ornamental Horticulture Production and Integrated Pest Management

News alerts and tips from Southeastern universities.

Cottony maple leaf scale eggs hatching

Cottony Maple Leaf Scale is one of several cottony scales in the genus Pulvinaria.  You can find these now on their most common hosts: maple and dogwood.  Stand under a tree and look up and you will see cottony masses about the size of a cotton swap stuck to the bottom of leaves.  These are the egg masses. They each contain many hundred eggs that are hatching as we speak.  The crawlers will settle and feed on the leaves all summer then migrate back to branches in fall before leaf-drop. For more pest updates follow @OrnaPests on Twitter or keep an eye on the blog from North Carolina State University.

Looking up at the bottom of red maple leaves notice the many white cottony egg masses. Photo: S.D. Frank

Looking up at the bottom of red maple leaves notice the many white cottony egg masses. Photo: S.D. Frank 


Cottony maple leaf scale ovisac. Photo: S.D. Frank

Cottony maple leaf scale ovisac. Photo: S.D. Frank

The UGA Extension Plant Pathology Update for May

Download it HERE:
It contains:
  • April 2013 Plant Disease Clinic Report
  • A look ahead for what you might expect to see based upon samples we diagnosed a year ago in May 2012
And, updates on:
  • Pseudomonas syringae leaf spot on watermelons
  • Fusarium wilt of watermelon
  • What’s the orange goo growing on tree stumps?
  • Rose Rosette Virus
  • Impatiens downy mildew
  • Wet, cool weather has importance for early-season disease management (row crops)
  • Wheat Diseases: Loose Smut, Sooty Mold, and Head Scab
  • Turfgrass Diseases: Large Patch, Dollar Spot, and Spring Dead Spot

April edition of the UGA Extension Plant Pathology Update

The April Update includes:

  • March Plant Disease Clinic Report
  • Table of plant disease samples diagnosed a year ago in April 2012
  • Eastern red cedar rusts
  • Bulb mites and spot anthracnose samples
  • Watch out for downy mildews on ornamental plants
  • Fungicide spray guide for Spring-planted peppers
  • Wheat foliar disease update
  • Turfgrass disease update
  • Winter weather in March could affect row crop diseases
  • Bacterial leaf scorch on blueberry research results
  • Corrected contact information

See the entire report HERE

Plant Disease Clinic Report for February 2013

By Ansuya Jogi and Jean Williams‐Woodward

The tables in the link below consist of the commercial and homeowner samples submitted to the plant disease clinics in Athens and Tifton for February 2013 (Table 1) and one year ago in March 2012 (Table 2). Sample numbers were still low in February, but this will soon change! Much of the symptoms we saw on samples were due to environmental stress/injury. However, root and crown diseases caused by Phytophthora, Thielaviopsis basicola, and Rhizoctonia continue to be identified. Also, with the cooler, humid, wet weather, the fungus, Botrytis, will continue to cause problems in the field and in greenhouses, particularly on freeze damaged tissues. Looking ahead through March, based upon samples diagnosed a year ago, we will likely see an increase in turf samples and problems, as well as rust and Sclerotinia diseases starting to show up. I would suspect too that downy mildew diseases will also become prevalent on some crops, particularly on ornamentals in nurseries. 

Evaluation of fungicides for the prevention of boxwood blight, 2012.

K. L. Ivors, L. W. Lacey, and M. Ganci

Dept. Plant Pathology, North Carolina State Univ.

455 Research Drive, Mills River, NC 28759

This trial evaluated the efficacy of several commercially available fungicides for preventive activity against boxwood blight caused by Cylindrocladium buxicola. Treatments were arranged in a randomized complete block design consisting of four replications of six 1-gal English boxwood plants per treatment on a container pad at the Mountain Horticultural Crops Research Station in Mills River, NC. Treatments were applied as foliar sprays until runoff with a CO2-pressurized backpack sprayer equipped with a handheld boom and a single, hollow-cone nozzle (TXVS-26) delivering 50-60 psi. Treatments were applied on 13 Sep, 28 Sep, and 13 Oct. Inoculum was prepared by flooding Petri-dishes of 10 day cultures of the pathogen growing on PDA. Plants were spray inoculated with 5,000 spores per ml until runoff one day post treatment on 14 Sep, and again on 30 Sep, two days after the second fungicide treatment with 8,000 spores per ml until run-off. Disease assessments were conducted on 1, 16 and 26 Oct. Percent leaf area diseased was recorded using the standard Horsfall-Barratt scale. Disease pressure was not high enough to evaluate percent leaf drop or percent stem streaking. AUDPC for percent leaf area diseased across the entire timeframe of the trial was calculated. Air temperatures during the trial was suboptimal for high rates of infection with average daily high and low temperatures of 77.7 and 55.4°F for Sept; and 66.3 and 43.5°F for Oct.

For the entire article – click here.

Regulatory Plant Issues for Nurseries

Regulatory Plant Issues: What You Must Do to Sell, Import or Export Live Plants from the State of Kansas
Jeff Vogel, Kansas Department of Agriculture

How do you stay up to date with plant quarantines, emerging pest threats and noxious weed lists? It can be very difficult to keep track of importing/exporting issues as well as other live plant sales concerns. Learn the most important aspects of regulatory plant issues from the state perspective.


Jeff is the Program Manager for the Plant Protection and Weed Control Program for the Kansas Department of Agriculture. His office works to ensure the health of the state’s native and cultivated plants by excluding or controlling destructive pests, diseases and weeds. His staff examines and analyzes pest conditions in crop fields, rangelands, greenhouses and nurseries.

“Bringing Nature Home”, sponsored by the Georgia Exotic Pest Plant Council

Do you care about protecting our native plant habitats from invasive plants? How can you tell which plants are invasive? Do you want to know how you can help? First step is to come to the Georgia Exotic Pest Plant Council Annual Conference on November 8th.

The GA-EPPC, Georgia Exotic Pest Plant Council, is having its Annual Meeting and Conference on Thursday, November 8th, 2012, from 9am to 4pm. The conference will be held at Stuckey Conference Center, UGA 1109 Experiment Street Griffin, Georgia.

GA-EPPC’s goals are to focus attention on the adverse effects invasive plants have on the diversity of Georgia’s native plants and animals; the use of invasive plant management to prevent habitat loss; the socioeconomic impacts of these plants; changes in the seriousness of the different invasive plants over time and the need to exchange information to help land owners and managers set priorities for invasive plant management.

For more information please visit

Redheaded pine sawfly


The redheaded pine sawfly, Neodiprion lecontei, is a pest of pines in ornamental landscapes, nurseries, and plantations. Adults emerge in spring and a second generation occurs in mid summer.  Eggs are laid on many 2 and 3 needled pine species such as Jack pine, loblolly pine, and red pine.  Sawflies are not flies and the larvae do not turn into butterflies. They are non-stinging herbivorous wasps.  They can defoliate trees and bushes in the landscape. Since they are gregarious it is sometimes possible to prune off an infested branch and remove all the larvae.  Management for sawflies is similar as for caterpillars though not all the insecticides will work so check the label.  Horticultural oil is a good bet especially for small larvae. Formulations that contain azadirachtin or spinosad are also effective.  For sawflies and caterpillars, management of full grown caterpillars is generally not warranted;  the damage is already done and they are hard to kill.

For pictures of redheaded pine sawfly larvae and more information visit:


UT Extension Hosts Landscape Review

JACKSON, Tenn. – For landscapers, growers or retailers who wish to stay current on best management practices for turf and landscape, UT Extension is hosting a field day for you.

The 2012 Landscape Review will take place on Tuesday, September 11, at the West Tennessee AgResearch and Education Center in Jackson, Tennessee. The Landscape Review will feature walking tours of the UT Gardens Jackson, an overview of plant trials used to evaluate better plants for Tennessee landscapes and updates on current pest, disease and weed control methods. A complete breakdown of the sessions is as follows:

9 a.m. – Using Turfgrass Weeds, Insects and Diseases as Indicators
10 a.m. – Walking Tour I: Tough Pest Resistant Plants
11 a.m. – Update on Ornamental Plant Disease and Recommended Control
Noon – Lunch (on your own)
1:15 p.m. – Walking Tour II: Tough Pest Resistant Plants
2:15 p.m. – Update on Ornamental Plant Pests and Recommended Control

This program will provide five pesticide recertification points in C3, C10 and C12. Points will be awarded at each session.

Admission is $10. For more information, including directions to the West Tennessee AgResearch and Education Center, go to

While Landscape Review is designed to be an information field day for those in the horticulture industry, interested gardeners are also welcome to attend.

UT Extension operates in each of Tennessee’s 95 counties as the off-campus division of the UT Institute of Agriculture. An educational and outreach organization funded by federal, state and local governments, UT Extension, in cooperation with Tennessee State University, brings research-based information about agriculture, family and consumer sciences, and resource development to the people of Tennessee where they live and work.


Susie Nicholson, UT Extension, 731-425-4717,
Ginger Rowsey, UTIA Marketing and Communication Services, 731-425-4768,

Leaf Spots in the Landscape

Elizabeth Little/Extension Specialist

Department of Plant Pathology, University of Georgia


Many areas in Georgia are experiencing warm, humid weather with frequent

thunderstorms this month. This is the perfect weather for fungal leaf spot

development in the landscape. Most leaf spots are benign and will not damage

the plant. Cercospora Leaf Spot of Hydrangea is an example of a leaf spot

disease that commonly occurs during prolonged wet weather or under sprinkler

irrigation. As with most leaf spots in the landscape, chemical treatment is rarely

needed. Some leaf spotting and leaf drop will not the harm the plant.

Management of leaf spot diseases involves removing sources of the disease and

protecting the plant. Start by selecting plants that will thrive where they are sited.

The fungi that cause these diseases mainly survive on the infected leaves that

fall to the ground, so removing and destroying diseased leaves can help lessen

the amount of disease next year. Stressed plants are more susceptible to

disease, so check the cultural conditions and optimize them with fertility

management and mulching. Good air circulation around plants will lower the

humidly and leaf wetness and reduce disease. Avoid wetting the leaves when

irrigating landscape plants.

If the plant is repeatedly defoliated each year or appears to be dying back

because of the disease, prune out the affected stems and use fungicides

preventatively (before the symptoms) to protect new growth.


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