A Letter from the PresidentDear Fellow MAA Members:

What happened to 2011? It’s hard to believe another year is coming to a close. I would like to thank all of the volunteers who gave their time and effort to make this year very educational to the membership. We were able to kick off the year with a well presented winter meeting, followed in March with a weeklong climbing course and a plant health care training day in the summer.

I had the pleasure of being one of almost 200 participants to attend the MAC-ISA’s inaugural day of safety held in Arlington, VA. It was exciting and encouraging to see the turn out. Safety is everyone’s responsibility and I hope next year will bring about new opportunities in which everyone may participate. I would like to take a moment to say, job well done!

This year’s winter meeting is shaping up to be another good one. With the pending regulations coming from MOSH, the meeting has been tailored to inform you of what to expect. In addition, CPR and first aid training is being offered at a fraction of what it would cost for an outside company to train your employees. This is a great opportunity to have your employees certified!

I hope to see all of you in January.

Steve CastrogiovanniMAA President

JANUARY 2012

In this Issue:

2 Landscape Technology Courses at Montgomery College

4 Calendar of Events

5 Imprelis: Great Expectations and Total Disaster!

9 Add Another Invasive Beetle to the List

10 No Ordinary Tree Removal

OUR MISSIONThe mission of the

Maryland Arborist Association, Inc. is to promote education in the

field of arboriculture, to support the success of arboriculture and

to promote the importance of tree care. The association will provide

a forum for the exchange of information and will encourage

professionalism through the collective efforts of the members.

S a v e t h e D a t e S

2012 Maryland arborist association Volunteer arborist days

The MAA will sponsor two volunteer events in 2012. The first is scheduled for April 14th at the Maryland School for the Deaf in Frederick. The second is tentatively scheduled for November 10th at the World War I Oak Grove Memorial in Druid Hill Park, Baltimore City.

Stay tuned for more details.

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Montgomery College, Germantown Campus, offers a variety of horticulture courses which are beneficial to those in the Green Industry, master gardeners, or plant lovers. Courses are offered at the Germantown Campus and at Brookside Gardens in Wheaton, Maryland. Plant Materials II (LN 109) identifies and explains the characteristics of native and non-native trees, shrubs, vines and groundcovers appropriate for central Maryland. The class is offered in two sections. The Monday afternoon section, begins January 23; it meets at Brookside Gardens, Wheaton from 1:00 p.m. to 4:30 p.m. The Wednesday evening section meets at the Germantown Campus from 6:00 p.m. to 9:30 p.m. This class starts January 25. These classes offer several optional field trips including trips to the National Arboretum, the gardens at the Hillwood Museum and British Embassy, Raemelton Farm, and Pope Farm Nursery. Additional courses offered by the Landscape Technol-ogy Program include: Introduction to Landscape Technol-ogy, Landscape Design, Landscape Management, and a

Landscape Technology Courses at Montgomery College

relatively new course Plant Propagation and Production. Students can take any of these classes for credit or audit. In-county tuition rates are available for Business/Industry employees. Businesses or other organizations that do business in the state of Maryland may be eligible to enter into an agreement with the College that affords their employees or members tuition and fees at the in-county residence rate, regardless of actual domicile. ■ For further information about the program/courses contact:

Steve DubikProfessor, Landscape Technology Program20200 Observation DriveGermantown, MD 20876240-567-7803steve.dubik@montgomerycollege.eduFind program information on the web at: http://cms.mont-gomerycollege.edu/edu/department2.aspx?id=13468

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January 11 – 13, 2012MANTS – Mid-Atlantic Nursery Trade ShowLocation: Baltimore Convention CenterContact: www.mants.com or 410-296-6959

January 17, 2012 – Sold Out.MAA and TCIA EHAP Confer-ence(Electrical Hazards Awareness Program)Location: Mead Tree and Turf Care, Inc., Woodbine, MDContact: TCIA at 800-733-2622

January 18 – 19, 2012MAA Winter Conference and Pes-ticide RecertificationLocation: Turf ValleyContact: mdarboristassoc@aol.com or 410-321-8082

January 29 – February 2. 2012Mid Atlantic Horticulture Short CourseLocation: Newport News, VAContact: www.mahsc.org

February 9 and 10, 2012Chesapeake Green 2012 – A Horticulture SymposiumLocation: Maritime Institute of Technology, Linthicum, MDContact: www.chesapeakegreen.org

February 21 – 24, 2012ASCA Academy – American Soci-ety of Consulting ArboristsLocation: Philadelphia, PAContact: www.asca-consultants.org

March 2, 2012Lewis Ginter Botanical Garden Tree Care SymposiumLocation: Richmond, VAContact: www.lewisginter.org or 804-262-9887 x322

March 6 – 8, 2012MAC-ISA Arborist Certification CourseLocation: to be determined (as of Dec 21)Contact: 703-753-0499 or www.mac-isa.org

April 14, 2012 (rain date April 15)MAC-ISA Tree Climbing ChampionshipLocation: Wheaton, MDContact: admin@macisa.org or 703-753-0499

April 17, 2012CPH Basic ExamMust be pre-registered to participateContact: www.mnlaonline.org, mnacma@aol.com or 410-823-8684

April 21, 2012 (rain date April 28)MAA Volunteer Arborist Day (one of two volunteer days in 2012)Venue: Maryland State School for the Deaf, FrederickContact: MAA at mdarboristassoc@aol.com or 410-321-8082

Calendar of Events 2012

July 17, 2012Specialist Exam – Integrated Pest ManagementSpecialist Exam – Herbaceous PerennialsMust be pre-registered to participateContact: www.mnlaonline.org, mnacma@aol.com or 410-823-8684

August 11 – 15, 2012International Society of Arboriculture88th Annual ConferenceLocation: Portland, ORContact: www.isa-arbor.com

October 16, 2012CPH Basic ExamMust be pre-registered to participateContact: www.mnlaonline.org, mnacma@aol.com or 410-823-8684

October 16, 2012Specialist Exam – Advanced Plant IdentificationMust be pre-registered to participateContact: www.mnlaonline.org, mnacma@aol.com or 410-823-8684

November 10, 2012 (tentative date as of Dec 21, 2011)MAA Volunteer Arborist Day (one of two volunteer days in 2012)Venue: World War I Memorial in Druid Hill Park, BaltimoreContact: MAA at mdarboristassoc@aol.com or 410-321-8082

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By the end of May 2011, our industry had suffered through two months of excessive rainfall (March and April) and an excessively warm month (May). Things were just starting to settle down when reports of tree damage started filtering through the industry. White Pine and Norway Spruce started showing noticeable browning of their foliage Along with the damage were reports of herbicide usage at these sites. Imprelis herbicide by DuPont was deemed the culprit. Scientific Plant Service made the decision to use Du-Pont’s new Broadleaf Weed Killer, the previous winter for spring 2011 usage for several reasons. First, it was new and improved chemistry. It was a low use product (4.5 oz per Acre!). It had low mammalian toxicity and was supposed to have minimal impact on the environment. Imprelis was supposed to be the answer to the 30 year old problem of how to manage wild violets. The product was also supposed to help suppress crabgrass. Cost per acre was significantly higher than the old standard chemistry- three-way phenoxy herbicides. The decision to use this new product also hinged on thorough weed and crabgrass control, coupled with the reduced likelihood for call-backs for weed problems. Once it was established that Imprelis was the factor behind browning and dying trees, SPS made the switch to the old standard, three-way type herbicides for late spring weed sprays (after 6/2/11). SPS then checked all records in reference to out clients who received Imprelis applications. Most sites that were sprayed with Imprelis were to the south of Baltimore, including Suburban Maryland (D.C. Suburbs), Southern Maryland, and Northern Virginia. Yours truly then spent the better part of the next three weeks inspecting more than 275 sites to check for possible Imprelis damage. I was primarily searching for damage to White Pine and Norway Spruce as these were the only trees that were known to have sustained damage. My initial inspections yielded only a few sites that had obvious damage. Con-sidering the large number of applications made, I felt that perhaps Scientific Plant Service had dodged the bullet as to widespread damage. Little did I know! I had my suspicions that there were other plants af-fected - Bald Cypress and Honey Locust, as these trees did not look quite right during my June inspections. One site in Potomac had a line of Norway Spruce that were behind a tennis court and nowhere close to where material had been applied. Yet an arborist told these folks that their

Imprelis: Great Expectations and Total Disaster!

What a stressful season! If all the early rain and extreme heat wasn’t enough, we then had to contend with an earthquake, a hurricane and a tropical storm at the end of the summer!

“

”

(continued on next page)

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Photographic evidence of Imprelis damage

7Norway Spruce had sustained Imprelis damage. (To date these trees never developed additional browning, so it had to be coincidental environmental stress, probably from the excessively hot May weather). July 2011 was the single hottest month ever recorded in the Middle Atlantic area. This weather event seemed to accelerate the damage to trees. After telling those clients whose trees had suspected damage to water those trees, per DuPont’s recommendations, these trees appeared to sustain additional damage. By August 2011, the calls were flooding in to our office regarding browning trees. Several HOA’s in Timonium has sustained major dam-age to their evergreens. Tom Mayer, from T. D. Mayer Consulting, acted as a consultant to determine the extent of the damage to these sites. By Tom’s calculation, one

site had a dollar amount closing in on SIX FIGURES from the Imprelis. Taxus, Butterfly Bush, Mulberry, Weeping Willow, Maple, Blue Atlas Cedar and Doug-las Fir had shown damage on various

sites. I then made another series of site inspections on those properties I inspected in June. Most were damage-free, but a number were showing brown foliage (thanks in part to the extreme heat in July) and many that had minor damage in June were defoliated (Honey Locust). In late September, I met two consultants hired by DuPont to do their own inspections. One was from Steri-cycle, the other from Davey Tree, Buffalo NY. The three of us inspected a site in Annapolis, one in Pasadena, and a commercial site in McLean, Va. The site in Annapolis had 4 each 7-8’ Norway Spruce listed on the report, two of which had been removed. The other two sustained minor damage. The site in Pasadena had 2 each 30-40’ Norway Spruce that had been damaged. Further inspec-tion showed a large Deodar Cedar with browning. There was also a 5’ False Cypress with tip browning. One of the consultants said it was Imprelis damage. I asked “are you sure?”, because to my eye it looked like environmental stress from the July heat. I was told that, no, it was from the herbicide. I then met them the next day at Tyson’s Corner, VA to inspect an office building that had 24 ma-ture Honey Locusts, 2 large Norway Spruce with Imprelis

damage and suspected damage to a Red Oak. Three of the Locusts had 0% damage because they were in raised plant-ers and the Oak had scorch. The rest were all damaged. What a stressful season! If all the early rain and extreme heat wasn’t enough, we then had to contend with an earthquake, a hurricane and a tropical storm at the end of the summer! Finally by October, things started to quiet down, as no more damage had shown up. Despite DuPont’s assertion early on that the damage was from applicator error, the company finally reversed its stance and accepted responsibility for the dead and dying trees. Twenty years ago, I worked in distribution with Lea’s Green Meadows out of the D.C. area. There were reports of damage from the use of Benlate or Tersan 1991 Fungi-cide (a DuPont Product). The problem with this material was that the manufacture of Benlate had been contaminat-ed with herbicide from the plant next to the Benlate plant. In my opinion, Benomyl, (the active ingredient in these products) was the BEST fungicide on the market. It was widely used in agriculture, greenhouses, arboriculture, golf courses, turf and ornamentals, because it was systemic, had a wide label as to various diseases, and was very effective. DuPont sustained a major financial setback from the dam-age from Benomyl and the loss of the sale of this product. DuPont accepted claims for tree damage through the end of November 2011. For those lawn care firms and golf courses that had tree damage, February 1, 2012 is the deadline for sending completed claims forms to DuPont. DuPont also has a return and refund program for Imprelis herbicide, as the material has lost EPA registration. Should anyone have questions or concerns about Imprelis, please call 866-796-4783 (DuPont Imprelis Hotline). There are concerns about the herbicide having soil activity persisting into 2012 and beyond. Frankly, no one can answer this question at the present time. I recently attended two seminars that had sessions dealing with this major problem. There was discussion about not planting the same trees in areas that had Imprelis applications for the near future. I agree with the logic with this situation because of the concern about sustained herbicide activity. How will all of this wash out? Time will tell. Good rid-dance, Imprelis! ■

Damian VargaScientific Plant Service

Finally by October, things started to quiet down, asno more damage had shown up.

“

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Insurance Specialists for the Green Industry

Delivering Customized Insurance Solutions & Exceptional Service Since 1977

MATT SIMMONSVice President

GEORGETOWN INSURANCE SERVICE, INC. 10010 Colesville Road, Suite A

Silver Spring, MD 20901Tel: 301-681-9645 • Fax: 301-593-2590

matt@georgetownins.com

www.georgetownins.com

9

We received in a sample from an arborist in Harford County that was a longhorned borer found attacking Leyland cypress. Right after this, MDA reported finding a longhorned borer in Cryptomeria in the Anne Arundel County. This longhorned beetle found in Anne Arundel was confirmed by Gaye Williams as Callidiellum rufipenne commonly called the Japanese Cedar Longhorned Beetle, Cedar Longhorned Beetle, Smaller Japanese Cedar Long-horned Beetle, or Lesser Cedar Longicorn Beetle. Known Hosts: In Asia the Japanese cedar longhorned beetle is considered a secondary pest attacking stressed and freshly cut conifers. Known Asian hosts include Japanese cedar (Cryptomeria japonica), Hinoki cypress (Chamaecyparis obtusa), Sawara cypress (Chamaecyparis pisifera), false arborvitae (Thujopsis dolabrata), firs (Abies spp.) and pine (Pinus spp.). In Connecticut this beetle has been observed in healthy American arborvitae plants. In its introduced range in the United States and Europe, hosts include eastern redcedar (Juniperus virginiana), American arborvitae (Thuja oc-cidentalis), juniper (Juniperus communis), and Monterey cypress (Cupressus macrocarpa). They do not have many Leyland cypress growing in the Northern parts of America or in the Orient and it is not reported as pest there. It may be a different story here in Maryland with all the Leyland cypress planted in the landscape.Key ID Features (Adults, Larvae, Eggs): ■ Adults emerge from the host in early spring. They are 1/4 to 1/2 inch (6-14mm) in length with a slightly flattened body. Adult beetles are often found at the base of crotch where two branches meet.■ Male have antennae that are slightly longer than their body. They are an iridescent blue-black color with reddish areas on the upper corners of the wing covers (elytra). Females have shorter antennae, reddish-brown elytra, and an orange-red abdomen.■ Females lay small (1.4 mm), yellowish eggs in bark crevices in spring.■Larvae feed within the stems forming shallow, serpentine galleries just beneath the bark. ■The beetle pupates in the fall and over-winters as an adult inside the host. What to Look For and Description of Damage:■Small oval exit holes (less than 0.25 inch) are created by adults exiting the wood in the spring. ■ Puckering incisions along the bark result from larval mining. Frass can be seen in openings to the tunnels.

Fact sheets that will help you out in identifying this pest:Cooperative Pest Agricultural Survey: Links to resources, maps, and articles on Japanese Cedar Longhorned Beetle. http://ceris.purdue.edu/napis/pests/celb/

Japanese Cedar Longhorned Beetle in the Eastern United States USDA APHIS Pest Alert. http://www.aphis.usda.gov/lpa/pubs/jclbpale.pdf

Canadian Forest Service: Exotic Pest Advisory. http://ceris.purdue.edu/napis/pests/celb/alerts/pacanad1.html

Pest Management Page for Japanese Cedar Long-horned Beetle Ministry of Agriculture, Food, and Fish-eries, Government of British Columbia. http://www.agf.gov.bc.ca/cropprot/jlbeetle.htm

What to Do?If you find a longhorned beetle attacking Leyland cypress, arborvitae or Cryptomeria get a sample to us at CMREC, 11975 Homewood Road, Ellicott City, MD (Sgill@umd.edu) or to MDA in Annapolis.

Stanton Gill, Extension Specialist, IPM and Entomology for Nursery, Managed Landscapes and Greenhouses, CMREC, University of Maryland Extension and Professor with Montgomery College, Landscape Technology Program sgill@umd.eduwww.IPMNET.umd.edu

Add Another Invasive Beetle to the List – Japanese Cedar Longhorned Beetle Stanton Gill (Extension Specialist, CMREC)

10Article courtesy of Bartlett Tree Experts

11

■

Don’t Let Another Elm Die.

Rainbow took a stand in 1977 to save the American elm using only scientifically backed treatments. Much has changed in arboriculture over that time, but our commitment to science and saving trees has never faltered. Our tree care company treats thousands of elms every year and we only recommend tree health solutions that we use on our own clients’ trees. We stand behind Arbotect because it is the best solution available for saving elm trees. Period.

The Solution Center:877-272-6747www.treecarescience.com

A branch of the employee owned Rainbow Tree Companies

In the Mid-Atlantic:Jean Scott

410-430-4108jscott@treecarescience.com

QUICK TIP:

Macro-infusion treatments should take about

an hour regardless of the size of the tree.

If your treatments are taking longer, please

contact us for tips on how to make your

treatments faster and more profitable.

© 2012 Rainbow Treecare Scietific Advancements. Arbotect is a registered trademark of Syngenta Corp.

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The Maryland Arborist Association sponsorsaspecial state-issued license plate that displays the MAA logo, featuring the Wye Oak. Your $50 contribution will cover the MVA fee of $25 and provide $25 towards the MAA education fund.

If you are interested in purchasing this special plate, please send a check for $25 to the MAA, requesting the license plate application. MAA, in turn, will mail you the application for the plate, which you com-plete and return to the MVA with a separate $25 check. MVA will issue the plates.

Please send your requests to the MAA at:MAAPO Box 712Brooklandville, MD 21022

MAA LICENSE PLATES NOW AVAILABLE

Maryland Arborist AssociationBoard of Directors

July 1, 2010- June 30, 2012 Executive Committee Members

PresidentSteve Castrogiovanniscastrogiovanni@meadtree.com 301- 854-5990

President-ElectJohn Davis, jdavis@bartlett.com 410-526-6655

Secretary Jeremy Baker, jeremy@antietamtree.com 301-791-3500

TreasurerKevin Mullinary, kevin.mullinary@davey.com 410-377-4002

Immediate Past President Nicholas Valentine, nvalentine@lewistree.com 410-987-4815

DirectorsBob Mead, meadtree@meadtree.com 301-854-5990

Kirk Floyd, k.floyd@landscapeprojects.com301-652-8844

Frank Dudek, frankdudek@arborvalleytreeservice.com410-357-8445

Executive DirectorVanessa A. Finney, mdarboristassoc@aol.com410-321-8082

Maryland Arborist Association, Inc.P.O. Box 712Brooklandville, MD 21022Phone: 410-321-8082mdaboristassoc@aol.com

If you are losing jobs to the unlicensed, uninsured, low bid, so called tree expert and you want to protect your company, the one that is playing by the rules, then you should have the telephone number to The Maryland Natural Resources Police (NRP). NRP is the enforcement arm of the Department of Natural Resources (DNR). NRP is the only police force aside from the Maryland State Police that has statewide jurisdiction. If you call from any place in Maryland: 410-356-7060 to report unlicensed arborists, they will take action. All you have to do is call and give the address of the job site, the name of the company or person violating the law. A vehicle description, color, style, tag number, or whatever information you have to provide. The Maryland Natural Resources Police will take action, however, you must take the first step and make the call. You do not have to be involved beyond the initial telephone complaint. Operating a tree expert business without a license and advertising or soliciting tree work is unfair to the consumer and the honest business person as well as being illegal. ■

14How do You Compete With the Unlicensed Tree Expert? YOU CAN’T.

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Maryland DNR Tree Expert Exams

The following individuals have recently passed the Maryland Licensed Tree Expert Exam. Congratulations to these new LTEs!

William Shelton Haralampi Chopev Daniel Schrom Zachary Richardson John Polizos Cindy Sawyer

The Maryland Licensed Tree Expert exams for 2012 will be held on: January 11, 2012 February, 2012 (Notest) March 14, 2012 April 11, 2012 May 9, 2012 June 13, 2012 All tests are administered at DNR Headquarters in Annapolis. Pre-registration is required. Please call Ms. Romcesa Estep at 410-260-8531 or visit: www.dnr.state.md.us/forests/programspps/newtreeex-pert.asp, for an application.

Note: You will need to sign in at the front desk in the lobby. Valid photo ID is required for entry. Directions and parking information can be found at: www.dnr.state.md.us/map.html

Vermeer Corporation is pleased to announce that Calley Pittman, co-owner of Pittman Tree Inc., based in Front Royal, Va., is the lucky winner of the 100,000th piece of tree-care equipment manufactured by Vermeer. A specially decaled Vermeer® BC1200XL brush chip-per was presented to Pittman during the TCI Expo in Hart-ford, Conn., on Nov. 3. His name was drawn from nearly 6,000 customers from 11 countries who participated in the “Leading the Way to 100K” giveaway drawing, which launched at the Tree Care Industry Expo in 2010. “Our customers expect us to show up with reliable equipment and Vermeer has always been there for us,” said Calley Pittman. “We are excited to receive the 100,000th machine and celebrate this great achievement with Vermeer.” Pittman conducts work in Virginia, North and South Carolina, Maryland and the District of Columbia. His company owns a dozen pieces of Vermeer equipment, and the BC1200XL brush chipper will soon be part of his fleet. “This is a great achievement for Vermeer,” said Todd Roorda with Vermeer Corporation. “With the invention of the first stump cutter in 1957, not many companies within the tree-care industry can state they have built more than 100,000 pieces of tree-care equipment. It goes to show that if you build a quality product and provide exceptional service, customers will keep coming back.”

Vermeer Corporation of Pella, Iowa, U.S.A., manufactures a full line of tub and horizontal grinders, brush chippers, stump cutters and tree spades, as well as horizontal directional drilling systems, mini skid steers, utility and track tren-chers and agricultural products. Vermeer offers worldwide sales, support, service and parts through an independent, authorized dealer network. Vermeer and the Vermeer logo are trademarks of Vermeer Manufacturing Company in the U.S. and/or other countries. ■ Vermeer Corporation P.O. Box 200Pella, Iowa 50219salesinfo@vermeer.com

Vermeer Builds 100,000th Piece of Tree-Care EquipmentCalley Pittman Awarded Unit in Global Drawing

Pictured left to right; Scott Koenig, Calley Pittman, Charlotte Pittman and Walter Pittman

July 11, 2012August, 2012September 12, 2012(Notest)October 10, 2012November 14, 2012December 12, 2012

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When you stand in front of a sick or dying tree or shrub the cause of the plant’s problem often doesn’t jump out and bite you. The all too frequent tendency is to spray it with something in the hope that it will get better. One of the primary tenets in the IPM philosophy says, “Identify the cause of the problem before initiating any type of con-trol procedure”. Why then do we often spray first and di-agnose later? There are two reasons for this. First, it seems

like the easy way to go. Diagnosing the cause of plant problems is often hard. Spraying is easier, at least mental-ly. Second, we have all grown up in “a medicine society”. If it hurts, take two aspirin and call me in the morning. For many people, pesticides and fertilizers are like plant medi-cine. If the plant looks sick, give it fertilizer and spray it with a pesticide. A good plant professional however knows better. Diagnose first, spray if necessary later.

The First Step in Diagnosing Plant Problems Is Getting Answers to the Right QuestionsBob Stewart, Area Extension Agent, Retired, July 2005

A newly described insect/fungus complex, called thousand cankers disease, has been responsible for the death ofthousands of black walnut trees in the western U. S. for at least a decade. In the summer of 2011, the disease wasconfirmed for the first time in Virginia and Pennsylvania. We are asking Marylanders to be on the lookout for thislethal disease of black walnut trees.What is Thousand Cankers Disease? The disease is caused by a newly described fungus, Geos-mithia morbida,which is spread by a native insect, the walnut twig beetle (Pityophthorus juglandis). The beetles attack trees in largenumbers, and carry the fungus into trees when they create breeding galleries under the bark. The fungus invades thephloem around the beetle galleries, forming cankers that coalesce and eventually girdle the trunk and branches.

Look for:• Dead or dying black walnut trees• Trees with wilted or dead branches in upper crown• Trees with shoots sprouting from the lower trunk• Insect galleries (tunnels) and dark brown cankers just under the bark of branches or trunks of declining trees

Thousand Cankers Disease of Walnut–Plant Disease Alert

If you find a suspect tree, contact:UMD Plant Diagnostic Laboratory (301-405-1611)UMD Home and Garden Information Center (410-531-5556)Links to additional information:http://na.fs.fed.us/pubs/palerts/cankers_disease/thousand_cankers_disease_screen_res.pdfhttp://www.agriculture.state.pa.us/portal/server.pt/gateway/PTARGS_0_2_75292_10297_0_43/AgWebsite/ProgramDetail.aspx?name=Thousand-Cankers-Disease&navid=12&parentnavid=0&palid=137http://www.thousandcankerdisease.com/

Declining black walnut

Dark brown cankers around insect galleriesjust under bark▼

▼

17 Still, diagnosing the causes of plant problems is hard. I would like to utilize this IPM Web Page to help you learn to diagnose landscape plant problems. I welcome com-ments and questions as well go along. I will also be report-ing on a number of the landscape diagnostic visits I make during the year. Let’s start at the beginning with a general overview of the things that cause plant problems; they fall into four broad categories:1. PROBLEMS CAUSED BY THE PLANT’S ENVIRONMENT2. PROBLEMS CAUSED BY THE PLANT’S CARE3. PROBLEMS CAUSED BY INSECT, MITE AND OTHER ANIMAL PESTS4. PROBLEMS CAUSED BY INFECTIOUS DISEASE The plant’s environment includes the weather and soil conditions. Plant care problems include irrigation (both too much and too little), fertilization (almost always too much), and various injuries (herbicide injury is the most common). Most landscapers recognize the common insect, mite and infectious disease problems, but there are occasional run-ins with the more unusual pests, and these can some-times be confused with environmental or cultural problems. A careful examination is the first step toward a plant problem diagnosis. Try and put together a picture of what is taking place. Here are a few questions to try and answer:

What is the observable problem?Are the leaves damaged or falling off? Are the leaves brown or spotted in some way? Do the leaves appear to be eaten? Is the new growth malformed in any way? Are the branches still alive or have they died? It’s often important to know whether the problem is only affecting the leaves or whether additional parts of the plant are also affected.How much of the plant is affected? Is the problem occurring over the entire plant? If not, what part of the plant is affected? Is it the bottom of the plant, the top of the plant, or maybe just one particular branchor plant section? If the problem is confined to a particular branch or other section of the plant it is unlikelyto be caused by the weather or chemical application.When did the problem first appear? Has the problem been going on for sometime? Is it very recent? Did the problem start and one point on the plant and spread, or did it occur all over the plant at once? Often a problem that appears all at once can be associ-ated with a one time event, such as a late season frost, or injury from a chemical application. Problems that spread gradually over time are more likely to be associated with an infectious disease or a soil problem.

Are other plants in the area showing similar problems? Infectious diseases and many insect and mite pests have particular host plants. If a number of different types of plants in the area are showing damage it is more likely that an environmental or cultural problem is the cause, rather than a pest problem.Are insects or mites on the plants? Insect and mite pests are not invisible, if they are the cause of the problem you should see them. Check plant carefully. Check the backs of the leaves with a good 10X magnifying glass or hand lens.Is there any noticeable damage to the trunk or main stem of the plant? The effort is to figure out what part of the plant is dam-aged. Is it only the leaves? Is it the stem that is damaged and indirectly affecting the leaves? Is it the roots that are affected and indirectly affecting the leaves? We know that if the roots are damaged the leaves will ultimately be af-fected. Therefore, it is important to try and figure outwhether the leaves are being directly affected by a pest, or by the weather, or by some type of chemical injury, or the leaves are being indirectly affected by damage to the plant stems, or indirectly affected by damage to the root system. Finally, always be aware of the weather and it’s con-sequences. This winter has been wet and relatively mild. What does that indicate for the spring? Well, it’s not very likely we’re going to have problems with salt injury on landscape plants. When there’s no snow and ice, there’s no salt application. It’s not likely we’re going to have prob-lems caused by drought and desiccation. Brown leaves on rhododendrons and magnolias this spring will NOT be due to wind, sun and frozen soil. However, the ground is satu-rated with moisture. Continued above normal rainfall into the spring can mean root damage from water backing up in planting holes. When roots are damaged, and the weather turns warmer, we’ll see wilting and brown foliage.

The information given herein is supplied with the under-standing that no discrimination is intended and no endorsement by Maryland Cooperative Extension is implied. Read labels carefully before applying any pesticides. Photographs are by Suzanne Klick and Stanton Gill unless stated otherwise.University of Maryland Extension programs are open to all citizens without regard to race, color, gender, disabil-ity, religion, age, sexual orientation, marital or parental status, or national origin.

Declining black walnut

Dark brown cankers around insect galleriesjust under bark▼

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