T R E ET I P S

B A R T L E T T T H E F. A . .B A R T L E T T T R E E E X P E R T C O M P A N Y

Plants, like humans, are subject to illness anddeclining health. Disease pathogens and insectpests cause a variety of plant problems, includingloss of aesthetic value, decline, death, and structuralhazards. Accurate diagnosis of plant problems iscrucial because treatment timings and products usevary from pest to pest. Knowledge of the causalagent is required before effective treatments can beapplied. When the causal agent can be identifiedon the plant, accurate diagnosis and treatment pro-grams can be developed on site. Bartlett Arboristsare highly skilled at identifying pests and environ-mental damage from plant symptoms. However,when similar symptomsmay be caused by differentcausal agents or the causalagent may not be apparent,a sample must be collectedand submitted to a diagnosticclinic for further evaluation.Bartlett Arborists rely on theBartlett Plant Diagnostic Clinic(BPDC) at the Bartlett TreeResearch Laboratories inCharlotte, NC to analyze and diag-nose pest and cultural problemsof trees and shrubs on client prop-erties at no additional charge. Our newly renovatedclinic is equipped to perform microscopic analysis,conduct serological tests, and isolate plantpathogens from plant tissue for accurate diagnosis.

The first step in diagnosing a plant problem isto collect and submit an appropriate sample froma symptomatic plant. We use a web-based digitalsubmission system to facilitate sample submissionand improve response time once the sample arrivesat the clinic. Bartlett Arborists enter informationabout the sample including symptoms, soil condi-

tions, environmental fac-tors, and previouslyapplied treatments to aidin the diagnosis. Digitalphotographs of sympto-matic plants can also besubmitted for analysiswith or without submis-sion of a physical sample.

Every aspect of the diagnostic process fromsample submission, diagnosis, treatment recom-mendation, and production of the final diagnosticreport is managed through the digital sample sub-mission system. This system also stores and col-lates all data that is submitted so that BartlettArborists can trend plants, problems and problem

locations. This helps us trainArborists and Monitor IPM tech-nicians and assists with earlydetection and treatment ofproblems on client properties.

The diagnostic staff atthe clinic analyze over 9,000

plant samples from every geographic region withinthe U.S. and Canada each year. In addition, theBPDC collaborates with other organizations to stayat the cutting edge of technology, techniques, andnewly emerging plant health concerns. In 2008, theBPDC was the first private diagnostic lab to begin apartnership with the National Plant DiagnosticNetwork (NPDN). The NPDN was established in2002 by the USDA with the intent to form a networkof Land Grant University and State plant diagnosticlabs. The primary mission of the NPDN is to promoterapid detection and communication of high priorityplant pathogens and insect pests posing a threat toplants. The NPDN also allows the BPDC to remainalert to new and emerging diseases and insectpests that are constant threats to the horticulturalindustry. Bartlett will continue to monitor thesethreats due to increased global trade, movement ofornamental plant material across geographic areas,and Bartlett’s national presence and expansion intonew areas. �

Are My Plants Sick? Getting a Diagnosis

Find out about reforestation at: www.arborday.org/replanting

Summer PlantHealth Care TipsSummer is the traditional time to prune spring flow-ering trees and shrubs to help maintain size andshape of plants. Major pruning performed beforeflower buds set in late summer will enhance nextyear’s bloom. Light pruning also should be done onbroadleaf evergreens, conifers and plants used ashedges to maintain size and appearance.

As weather turns hot and dry, pay close attention towater requirements of plants. Woody plants benefitfrom infrequent but deep watering once plants areestablished. New transplants and plants grown inconfined spaces will require more frequent irrigationwhen regular rainfall does not occur.

Pests that are traditionally active in summer includespider mites, Japanese beetles, insect scalecrawlers, lacebugs and webworms. Powdery mildewbegins to become severe as weather turns warm andhumid. Deer browse becomes a major concern espe-cially on annuals and perennials. Repellents that areused to deter browse must be applied more fre-quently to protect new growth as it develops

Get Electronic Tree Tips – Plant a Tree!When you use our link below to enroll in our paperlessprogram, you can choose to plant a tree. We’ll sponsoryou for the Arbor Day Foundation’s reforestationproject. www.bartlett.com/newsletter

Find your client code in the yellowbox on the reply card included withTree Tips. It looks like the sampleat right. Then, go to the registra-tion link and sign up.

You can always return to mail serv-ice if you prefer a printed copyof Tree Tips. �

samplecode no.

Many Bartlett clients have irrigation systems thatthey love to use, with the intention of enhancingthe performance of their landscape. However, it isimportant that we encourage the smart use of ourprecious water resources. Notonly that, but overwateringcauses root mortality and dis-ease and is a leading cause ofdecline of landscape plants.The following are some con-cerns and ideas on wise wateruse for you to consider as yourreview your next water bill:� Landscapes are consistent-

ly over-watered by an aver-age of 50% according tomany water agency audits

� Using evapotranspiration and soil moisture-based control systems (“Smart” controllers) cansave water where over-watering is occurring

� Using these technologies, water use might go upif the landscape was under-watered or irrigationsystem was poorly designed

� Efficient irrigation scheduling can reveal weak-nesses in irrigation system design

� No technology or monitoring can “fix” inefficientor weak irrigation systems – modifications to acurrent system may be necessary

� It doesn’t have to be expensive – an economicalrain sensor can be added tomost timers to keep the irriga-tion system from running whenit is raining; preventing wastedwater and runoff

An irrigation system audit should be performedby a certified landscape irrigation auditor (CLIA) toevaluate the need for adjustments, additions orretrofits to existing irrigation systems. Adjustmentsmade to conventional systems to deliver water moreefficiently will do landscapes and the environmenta favor. This service could result in less waterusage, a healthier landscape and perhaps more

successful plant health care programs.Think about this…

A typical 1/3 acre landscape witha conventional irrigation systemscheduled to run every other day for15 minutes uses 10,000 gallons ofwater per week. By using “smart”controllers, converting shrub andflower beds to low-volume (drip) irri-gation, and properly regulatingwater pressure, at least a 25% watersavings can be realized! That’s 2500gallons of water per week! Add upthe potential savings across allBartlett clients – it’s staggering howmuch water we could conserve while

improving our landscapes’ health and per-formance in the process. �

Smart Water Usage

Diagnosticians at the Bartlett Tree Research Lab-oratories have received dozens of samples of vari-ous conifers over the past few years with seeminglyunexplainable symptoms of decline. Spruce and firare most common. Decline is a term used for plantsthat exhibit progressive deterioration in health. Thisis evidenced by poor growth, stunting and discol-oration of leaves followed by premature defoliationand branch dieback. Many common diseases andinsect pests can cause these symptoms, but in mostcases these agents were absent from samples sub-mitted to the Bartlett diagnostic clinic.

The decline has become increasingly commonand widespread. Bartlett’s diagnostic staff has con-tacted dozens of state and university diagnosticiansand pathologists from across the country to deter-mine if they were seeing similar problems in theirareas. Responses as to the origin of the decline werevaried. Causes identified as the source were anincrease in common pathogens, climactic condi-tions, poor planting sites, and newly described dis-eases. Because Bartlett offices operate across sucha large geographic area, our scientists were able toconclude that while some of the above factors mighthave been involved in individual cases, there wasnot a consistent cause that appeared across all of

the areas affected by the problem. In response, ourdiagnosticians at the laboratory developed adetailed survey protocol and arranged for site visitsto try and get to the bottom of this mysteriousconifer ailment.

After two summers of inspecting sites across theNortheast and Midwest, it became clear that whilethe symptoms exhibited bythese trees may have beenvery similar, the growingconditions, disease andinsect pressure, and weath-er factors varied consider-ably by region. In mostcases the major cause ofdecline was determined ateach site, but there was noconsistency in these factorsbetween sites. For exam-ple, while spruce bud scaleand shallow soil mighthave been a factor in onelocation, the exact samesymptoms were arising due to over-irrigation andcanker disease in another, and prolonged drought ata third site.

Disease Watch: What is Causing Conifers to Decline?Overall this project illustrated a few very impor-

tant points about diagnosing plant health disorders.First, every tree grows in a unique environment.Generalizations about plant species, geographicregions, or weather conditions tend to oversimplifythe actual situation. Second, decline of maturetrees can rarely be linked to one specific factor. It is

usually related to severalinsect, disease, cultural andenvironmental conditions thatact in concert. And finally, manydifferent factors can lead tosimilar appearances and symp-toms, so keeping an open mindto all possibilities and payingclose attention to details arecrucial when diagnosing planthealth issues.

Our advice is to consultwith your Bartlett ArboristRepresentative about the con-dition of your landscape. Ifplant health care issues arise,

the Diagnosticians at our research laboratory willprovide information and recommendations for treat-ment on your property. �

Converting to low-volume irrigation may savethousands of gallons of water in your landscape

Rain sensors canreduce water waste bypreventing systemactivation during rain

Asian longhorned beetle (ALB) is a destructive pestof maple, birch, willow, elm and other hardwoodtrees. This Chinese import was first discovered inthe United States in Brooklyn, New York, in 1996.ALB was later detected in Chicago and New Jersey.In 2008, a large infestation was detected inWorcester, MA.

People living in regulated areas face uniquechallenges in protecting their valuable landscapeinvestment. During the summer months, eachfemale beetle chews 35 to 90 individual barkdepressions (called oviposition wounds) into thebark of numerous trees. Just one bark depression

will trigger tree removal to meet sanitationguidelines to eradicate this pest.

Research has determined that themost effective treatment in most

situations is a soil applied sys-temic insecticide containing

the active ingredientimidacloprid.

Yes, it can be amazingly beautiful. Ice storms par-ticularly, because tree limbs coated with a layer ofglistening ice reflect light like a prism and are anexquisite jewel of nature.

Arboriculturally speaking, ice storms are a dis-aster. These photos were taken by Auburn, MAArborist Representatative/Local Manager, JeffHehman and by Paul Fletcher, Assistant DivisionManager to document the aftermath of an ice stormthat hit the Auburn area particularly hard lastwinter.

When events like this occur, Bartlett offices areon “red alert” and mobilize crews and equipmentfor storm response. These crews work around theclock to clear fallen limbs and trees, eliminatingimmediate hazards and freeing up streets fortraffic.

Afterwards, when the storm has passed, prop-erties are inspected and remediation efforts begin.Any remaining hazardous situations areaddressed; trees and shrubs are pruned to elimi-nate broken limbs and necessary removals aremade. Properties are cleared and restored to“normal”.

It’s hard to lose valuable specimen trees andshrubs to a one-time event. It’s sad to see trees

Emerald ash borer (agrilus planipennis) wasfirst discovered in southeastern Michigan in 2002and has been since identified in several neighbor-

ing states includ-ing Indiana andOhio as well as inWindsor, Canada.

Emerald ashborer larvae feedin the outer sap-wood of ash treesand can rapidly

girdle stems and branches. Trees often die within1—3 years following the initial attacks.

Emerald ash borer is native to Asia includingChina, Japan, Russia and Korea. The insect affectsall ash species native to the Midwest. Adults are

capable of flying at least a half mile from the pointof emergence. In Ohio, infestations are expandingat approximately ¼ mile per year.

Long distance movement of emerald ash borerhas been attributed to transport of infested fire-wood and nursery stock.

Firewood should not be transported from areasknown to be infested by emerald ash borer.

Treatments are available to manage EAB andare most effective on a preventative basis. Themost effective treatment is a soil applied systemicinsecticide containing the active ingredient imida-cloprid. �

Pest Watch: New Invasive Borers

Winter In New Englanduprooted and limbs fallen on the ground. It’sexpensive to replace what’s been lost.

Periodic pruning assessment can reduce a lotof storm damage. Crown thinning, dead branchremoval, cabling and bracing and removal ofhazardous limbs are all prevention techniques toreduce damage for the inevitable storm events thatoccur in winter.

The entire country was subject to a lot of winterstorms this year. The Midwest and the northernstates were also hard hit. So, our advice is tohave your Arborist Representative assess and per-form storm damage reduction procedures to helpyour trees and shrubs withstand the whims ofMother Nature. Summer thunderstorms are on thehorizon! �

David Cappaert, Michigan State University, Bugwood.org

Marianne Prue, Ohio Dept of Natural ResourcesDivision of Forestry, Bugwood.org

David Cappaert, Michigan State University, Bugwood.org

published byT H E F. A . B A R T L E T T T R E E E X P E R T C O M P A N Y

(877) BARTLETT (877-227-8538) in U.S. and Canadawww.bartlett.com

©2009 The F.A. Bartlett Tree Expert Company

Question: I want to plant a small orchard in mygarden and would like to use varieties that canbe grown organically. Can you recommend somepest resistant varieties? Jed Stevens

Answer: There are many apple and pear vari-eties that are resistant to common foliage andfruit diseases as well as fireblight, which is apotentially lethal disease of susceptible vari-eties. AdamsCounty nursery in Pennsylvania hasan excellent website that lists and describes dis-ease resistant apples and pears:http://www.acnursery.com/acn_resistant.phpThis nursery is an excellent source of mail orderfruit trees as well. Selection of the specific vari-eties depends on the intended uses of the fruitand personal preferences on characteristicssuch as ripening time, sweetness, texture etc.When purchasing fruit trees, make sure youhave at least two varieties of each species thatbloom at the same time to ensure pollination.The website can guide you on selection of appro-priate pollinators.

The disease resistant varieties are suscepti-ble to certain peel diseases such as sooty blotchand fly speck that affect the appearance, but notthe quality, of the fruit. These varieties are alsovery susceptible to insect/arthropod pestsincluding aphids, mites, scales, Japanese bee-tles, plum curculio, coddling moth and applemaggot. Insecticidal soap and horticultural oilsare organic products that can suppress some ofthese pests. There are traps available for cod-dling moth and apple maggot to suppress dam-age to fruit by these pests. Benefical insectreleases can also be employed to help keepinsect pests and spider mites in check.

It is not as easy to grow stone fruits (peach-es, nectarines, plums and cherries) organically.Brown rot is a disease that affects these speciescausing decay of the fruit just prior to ripening.Early ripening varieties of cherry and plum mayescape this disease in some years and would beworth trying. Stone fruits are also very suscepti-ble to insect borers especially as the plant ages.Ensuring the root collar is not buried by soil ormulchwill help avoid borers. If borers are detect-ed early, they can be removed from the stemwitha knife to prevent serious damage.

Squirrels, birds and deer can also be seriouspests of all fruit trees. Fencing off orchards maybe needed to keep deer away from trees. Nettingmay be used to help exclude squirrels and birds.

Dr. Bruce R. Fraedrich

ASK DR.BRUCE In the early 1990’s, large-scale mortality of oaks and

tanoaks was observed in Marin County, CA. Thecause was not clear. A previously unknown species ofthe fungus-like organism Phytophthora was identi-fied as the causal agent in 1996. It was namedPhytophthora ramorum. Since then, the organismhas proven to affect a large number of plant species,with damage ranging from minor leaf spotting torapid death of the entire plant. Thedisease caused by this pathogen iscalled Sudden Oak Death (SOD) foroaks, and Ramorum blight for a num-ber of other plant species.

Phytophthora species cause rootrots, trunk cankers and leaf and stemblights on trees and woody ornamen-tals. A unique type of organism, it isnot a true fungus. Most Phytophthoraspecies require free water insoil to spread and infect newhosts, but P. ramorum sporesare produced on above-groundplant tissue and can be spreadby rain, wind, fog, or animals(including humans).

‘Sudden Oak Death’ is amisleading term because themortality of infected oaks is not always ‘sudden’. Thepathogen infects a large number of plants other thanoaks and does not lead to death for many species.The California bay laurel, camellia, and rhododen-dron are important to the disease cycle because theydevelop leaf spots from which large numbers ofspores are released, but the plant survives infection.These foliar or ‘sporulation hosts’ drive the epidem-ic by producing spores that can infect oaks. The dis-ease does not spread from oaks to other oaks. Thevirulence of SOD varies. The most severely affectedtree hosts are live oak (Q. agrifolia), black oak (Q. kel-loggii) and tanoak (Lithocarpus densiflorus). Blueoak (Q. douglasii) and valley oak (Q. lobata) appearto be resistant to infection.

Infected oaks develop bleeding cankers on thelower trunk that eventually expand and girdle thetree. Cankers appear as small, dark spots that ‘ooze’a dark amber liquid. Crown symptoms are very gener-

Sudden Oak Death Still a Major Threatal and usually appear as branch dieback, generalchlorosis, and canopy thinning. Symptoms on foliarhosts vary, but normally appear as spotting or blight-ing of leaves. SOD infected oaks are often attackedby ambrosia beetles and/or infected with the wooddecay fungus Hypoxylon spp. This hastens mortalityand leaves infected trees more prone to structuralfailure. P. ramorum does not produce any structures

that are visible to the naked eye.Laboratory analysis is required. Aculture of the pathogen from plantmaterial or molecular testing of plantmaterial is used to confirm the disease.

University of California researchersdeveloped a successful treatment forSOD with Phosphonate fungicides. Thisreduced-risk product is mixed witha bark penetrating carrier and applied

directly to the trunks of oaks.This systemic material directlyinhibits the growth of Phyto-phthora, and increases resist-ance by triggering the plant’simmune responses. It isimportant to remember thatthis treatment is most effec-tive as a preventative meas-

ure on healthy trees rather than as therapy fortrees showing symptoms. Due to this research,phosphonates are now being used to treat otherPhytophthora diseases in the U.S. Cultural treat-ments to help reduce the spread of SOD includeremoval of spore hosts, like the California bay, ifthey are near oaks at risk of infection.

This pathogen has been proven capable ofinfecting over 100 host species, and has beenfound in the landscape in 14 California counties. Asmall area of southern Oregon is also affected, asare several locations in Europe. Discoveries of thepathogen in nurseries are far more numerous andinclude Western Canada and several easternstates. Although the geographic distribution is lim-ited at this time, the ever-increasing interstate andinternational trade of plant material causesconcern that the disease range will eventuallyexpand. �

SOD bleeding canker

Symptoms on bay leaf