Archive for April, 2012

Sorting out the Florida Sabals: New EDIS Document

We all know and love our beloved Sabal palmetto palms, the Cabbage Palmetto, our state tree… but what about the other Sabal species?

Sabal palmetto.  Photo: UF Laura Sanagorski

Sabal palmetto. Photo: UF Laura Sanagorski

A new EDIS publication, Sorting out the Florida Sabals, describes our four Sabal species and how to identify them:

  • Sabal palmetto: cabbage palm
  • Sabal etonia: scrub palmetto, bush palmetto, bluestem, or corkscrew palmetto
  • Sabal minor: dwarf palmetto or swamp palmetto
  • Sabal miamiensis: Miami palmetto (rare or extinct)

Enjoy this new publication by David A. Fox, research assistant; and Michael G. Andreu, associate professor, forest systems; University of Florida School of Forest Resources and Conservation.

Thorn Bug – Early Spring Pest of South Florida Ornamentals

Numerous plant samples with Thorn bug (Umbonia crassicornis) have landed on my desk this week.  Professionals throughout the county will notice this insect as well.  This is a very interesting, unusual-looking insect!

INTRODUCTION ~ Thorn bugs have been noted in high frequency in the past several weeks (April 2012).  This insect can be found at all times of the year, but is more common in the cooler months of late winter and early spring.

Thorn bug and Sri Lanka weevil damage on powderpuff. Photo: UF Laura Sanagorski

HOSTS ~ Thorn bugs have recently been seen on powder puff trees (Calliandra spp.).  They can also be found on tamarind, wild tamarind, bottlebrush citrus, jacaranda, royal poinciana, and acacia trees.

IDENTIFICATION ~ Thorn bugs blend in with a plant’s foliage and often go undetected.  The sample in the photo to the left was examined for a few minutes before this insect was noticed.  The color is green or yellow with brown or reddish markings.  This insect can be identified by the adult’s pronounced thorn-like or claw-like horn.  Juvenile versions of this pest look quite similar but will be smaller in size and have three less-prominent horns.  Generally, one will find various stages of the thorn bug’s life cycle on one branch.

Thorn bug. Photo: UF Laura Sanagorski

LANDSCAPE MANAGEMENT ~ The population of this insect will drop on its own as warmer months approach.  Thorn bugs, like whiteflies and thrips, have piercing / sucking mouthparts that allow them to feed on the nutrients of a plant.  They also produce honeydew, which can support the growth of sooty mold.  Serious damage is not generally associated with this insect, making treatment generally unnecessary.  Horticultural professionals who determine that treatment is required will be able to manage this insect with horticultural soaps and oils, or other insecticides (such as those in the neonicotinoid family) labelled for use on the plant of concern.  Physical removal, such as with a heavy spray from a hose, will also greatly reduce this insect’s population.

~ Download a Printer-friendly version of this fact sheet here ~

References and Further Reading ~ 

Culbert, D.  (2004). Powderpuffs and thorns.  UF / IFAS Okeechobee County Extension Service.  Available at:

Mead, F.W., & Fasulo, T.R. (2004).  Featured Creature: thorn bug.  Florida Department of Agriculture and Consumer Services, Division of Plant Industry.  Available at:

Next GI-BMP class May 15th – Have you and your employees completed this training yet?

If you haven’t taken the GI-BMP class yet, be sure to plan ahead – 2014 will be here before we know it!!  In 2012, the GI-BMP program will be offered by Palm Beach County on the remaining dates:

As a reminder to all green industry professionals ~ Beginning on January 1, 2014, all commercial fertilizer applicators will be required to hold a Limited Certification for Urban Fertilizer Applicators, issued by the State of Florida’s Bureau of Entomology and Pest Control.  The prerequisite of this license is the successful completion of the Green Industry Best Management Practices, or GI-BMP program, offered by the University of Florida IFAS Florida Friendly Landscaping™ program.  GI-BMPs teach safe landscaping practices that protect the environment, including our ground and surface waters.

To attend classes or learn more, see the 2012 GI-BMP Brochure.  GI-BMP training is also available online.  More information is  available on the Florida-Friendly Landscaping™ website. 

Call 561.233.1725 with any questions you may have.

Oak Leaf Blister

Oak Leaf Blister. Closeup view of leaf tip. Photo: UF Laura Sanagorski

INTRODUCTION ~ Oak Leaf Blister is not a disorder of great concern and is primarily aesthetic.  Oak Leaf Blister is caused by a fungus (Taphrina caerulescens).  Generally this aesthetic disorder is noticeable in the springtime – especially when we have cool, wet weather – the perfect condition for this fungus’ development.

HOSTS ~  Oak Leaf Blister affects Oak trees (Quercus spp.).

Oak Leaf Blister. Photo: UF Laura Sanagorski

SYMPTOMS / IDENTIFICATION ~ The first sign is small chlorotic (light-colored) spots on new growth of various oak species.  The spots will continue to develop into blisters.  The blisters may eventually fall out of the leaves, leaving holes behind.

Oak Leaf Blister. View from underside of leaf. Photo: UF Laura Sanagorski

LANDSCAPE MANAGEMENT ~ Treatment is not particularly warranted.  If you feel the need to treat for this blister, fungicides can be helpful, but should be used prior to spring bud break.

Download a printer-friendly fact sheet here: Oak Leaf Blister

Remember, the label is the law; be sure to use products only in a manner consistent with the manufacturer directions on the labels.  Please use pesticides safely.

Recording of Whitefly Workshop Now Available!!

Did you miss our April 10th Whitefly Workshop?  You can view the entire April 10th Whitefly Management Program polycom recording here.

This video has not been edited, but we wanted to share it immediately with horticultural professionals who missed the event.  It will be available for approximately three weeks, at which time it will be replaced with an edited video production.

Visit the Palm Beach County Whitefly Taskforce website for current versions of the presentations and fact sheets.


Strengthening Our Community Tree Canopy 2012 Urban Forestry Series for Professionals

Palm Beach County Cooperative Extension/ IFAS  will be offering an 8 class “Urban Forestry Series” to professionals in the horticulture industry. This series is a part of a project titled “Stengthening Our Community Tree Canopy Through Education”. This project is made possible by  a grant through the 2011 National Urban and Community Forestry Grant Program and the Florida Department of Agriculture and Consumer Services, and the Florida Forest Service.

The following is the 2012 Urban Forestry Series schedule for Professionals.

5/21: 6-7:30pm            Proper Selection of Trees for the Urban Landscape & Structural Pruning Techniques for Young Trees

6/18: 6-7:30pm   Installation & Maintenance of Hardwoods and Palms

7/16: 6-7:30pm     Root Pruning, Tree Transplanting, and Root Barrier   Selection & Installation

8/20: 6-7:30pm   Tree Risk Assessment & How to Decrease Liability By Identifying and Decreasing Tree Hazards

9/17: 6-7:30pm   Hurricane Preparation & Proper Restoration of Hurricane Damaged Trees

10/15: 6-7:30pm    Mangrove & Seagrape Pruning, State & Federal Regulations & Pruning Codes, Importance of Hiring an ISA Certified Arborist

11/01: 6-7:30pm    Proper Pruning of Fruit Trees in South Florida

12/03: 6-7:30pm    Establishing A Proper Fertilization Program, Importance of Water Quality in the Landscape

Download the 2012 Urban Forestry Brochure here.

Watch the Palm Beach County Extension Horticulture Blog for more details, or e-mail for more information.