Like most folks , I ’m particularly fond of redbud , and I treasure several in our pace . Two are volunteers — the most welcome military volunteer ever ! — but one of those volunteers suddenly started look unwell last summer . Its folio were spotty , but not the familiar brown spots of kingdom Fungi , such as Cercospora , which I ’ve discover to take in pace . SeeIllinois Ext . Then the folio get down to bend brown way too early , and eventually , some branches appear to be dead or dying . Research seemed to be in order ; after some metre on the computer , I began to worry that our Cercis canadensis might have a serious disease that had only recently appear on Tree in the U.S. But there were a few other diseases that present in a similar style , but none of them comfort my mind at all .
The most likely distrust wasBotryosphaeria canker sore and dieback — a fungal disease to which redbuds are quite susceptible , especially if they ’ve been stressed by drought . Symptoms of Botryosphaeria canker and dieback — which impact many species of trees and bush — are wilted or stagnant branches on a Sir Herbert Beerbohm Tree or shrub that see healthy in other respect . My redbud does have a few branches that seem to be idle . Here ’s what the experts at the Virginia Tech Plant Disease Clinic have to say about Botryosphaeria canker :
This is a common disease on Cercis canadensis . pestilence are often centered at arm stubs or other wound where the fungus gains entry . The fungus can also infect trees that have been sabotage by drouth , wintertime injury , or other environmental factors . No effective chemical control is usable . Prune out affected branches . Make pruning cuts several inches below the cankered arena , through respectable ( white ) wood . Pruning tools should be disinfested between cuts by dip in inebriant or in a 10 % solution of household bleaching agent to prevent spread to the newfangled wounds . touch to theVCE factsheeton this disease for further information .
— Plant Problem Image Gallery , Va Tech Plant Disease Clinic
How to protect your Cercis canadensis from Botryosphaeria fungal infection ? First of all , protect it from focus , and remember that any lesion could be an entry point for the fungus . Do not prune when it ’s wet ; only when it ’s ironic . And if you ’re pruning out morbid branches , watch the direction in this helpful video from Va Tech : www.youtube . VCE / Botryosphaeria Dieback – Common Plant Diseases in the Landscape and Garden . Also , if you ’re planting a novel redbud , be sure to allow its favour condition .
If you think one of your trees or shrubs has Botryosphaeria — and I was beginning to suspect that ’s what mine had — you ’ll want to transmit a sample to the Plant Disease Clinic at Virginia Tech . It ’s critical to provide them with a sampling branch that contains both healthy and diseased tissue ; i.e. , a leg that incorporate a “ junction of tidy ( white ) and diseased ( chocolate-brown to reddish - chocolate-brown ) tissue paper . ” This case of sample distribution is essential for diagnosing .
The next defendant on my list wasVerticillium Wilt , another fungal disease that affects many trees and ornamental shrubs , and for which there is no cure . It can be because of two unlike fungus kingdom , both of which reside in the soil , and sadly , can hang on in the soil for a longsighted time , infect new planting . The verticillium pathogen infects tree via root word and basically blocks the tree diagram ’s vascular system , prevent the transport of piddle and nutrient , leading to dieback and death . Just like Botryosphaeria , this disease is less likely to taint Tree that have optimal growing weather .
My redbud had the usual symptoms of verticillium wilt : “ wilt , shrivel , scorch or browning farewell ; off - colour foliage ; stunting ; defoliation ; dieback and death . ”Verticillium Wilt of Shade Trees and Woody Ornamentals / VA Tech . read about verticillium wilt was a rather scarey experience because my redbud is fence in by much - loved perennial that could be infected . Even if the disease progression could be slowed by deliberate tearing during summertime ’s teetotal periods , transplanting those perennial would just unfold the pathogen to a new area of the garden .
On top of the spreading - through - the - grunge return , there ’s even a problem with move out an infected tree — which is advocate if most of the tree diagram looks like sick . The cadaver can not be compost or chopped into mulch ( also contagious ) and must be landfilled — but not in an area where free mulch is being prepare ! All of these contagion problems dictate that only resistant species be institute in domain where verticillium has been diagnose . For a list of tolerant or immune species , as well as a leaning of susceptible species , seeVerticillium Wilt of Shade Trees and Woody ornamental . Verticillium wilts also affects a number of vegetable crop , though mostly in arena north of us . SeeVerticillium Wilt of Vegetables / Univ . Md. Ext .
Next on the list of suspects wasVascular Streak Dieback , a disease that appeared in parts of the United States in the retiring two twelvemonth , and which had formerly been know only as a disease of cacao plant in Southeast Asia . In Virginia , it has been redbud , maple , and cornel that have been apparent victims of vascular streak dieback ( “ VSD ” ) . Scientists are scrambling to learn more about VSD , and so far have not been able to make a positive identification of the effort . Here ’s a sum-up recently ready by a group of Virginia Tech researchers :
In the retiring two age , nurseries in Virginia and some other states have observed wilt disease and severe dieback on redbud , maple , and dogwood tree stock ( Beckerman et al . 2022 ) . In some case , 90 - 100 % of stock was unsellable due to the extent of damage . other symptoms include leaf greensickness , scorched leaf margins , and stunting and/or wilting of current yr ’s growth , eventually leading to death of single branches and progression into the main stem . wilt typically starts on the top of the works and progresses downwards into and along the main shank . Streaking or discolouration within the vascular , or weewee conducting , tissue appears when symptomatic offshoot and/or main stem are trim down . However , vascular symptom may be subtle or absent on dogwood or other hosts , add up a challenge for diagnosing . Commonly , opportunist fungus kingdom such as Botryosphaeria and Phomopsis colonize the weakened arm and have cankers , adding another challenge for detection of the primary causal agent .
The fungusCeratobasidium theobromae(synonym : Rhizoctonia theobromae ) has been consistently associated with vascular tissue of baby’s room stock show the symptom described above . This fungus has previously been reported as the movement of vascular bar dieback ( VSD ) on cacao in Southeast Asia ( Samuels et al . 2012 ) . Therefore , works pathologists in the United States are calling the putative disease VSD .
— Vascular Streak Dieback : An Emerging Problem on Woody ornamental in the U.S.
scientist are apprise that trees diagnosed withC. theobromaebe removed and burn . They are also suggesting that sound plants might be protect from contagion through the use of systemic fungicide soil drenches that are labeled for management of Rhizoctonia . To learn more about VSD , you ’ll require to readVascular run Dieback : An Emerging Problem on Woody ornamental in the U.S. , which also provides elaborated guidance on how to take a sample for diagnosis by the Virginia Tech Plant Problem Clinic .
After studying the three suspects and numerous photos of each disease , it became vindicated that professional help was needed . So , I follow the direction for taking samples of branches and soil and take them all to the Extension Office , where staffers mailed them to the Plant Disease Clinic at Virginia Tech . When an e-mail from the Clinic landed in my inbox , I took some deep breath and open up it . Which of the defendant was it ? None of them ! That ’s correct , near reader . Our redbud was a dupe of a problem I had not even considered : decay . The paper very helpfully detail the examination that had been done and resolve as follows :
Based on the impairment and appearance of the body in the photo submit , I think there is very likely decay in the primary luggage compartment of this tree diagram . Many different fungi have woods disintegration . Most decay fungi put down through wound ( e.g. planting injury , lawn lawn mower , weed whopper , etc . ) on accented Sir Herbert Beerbohm Tree .
– Plant Specimen Diagnostic Report # 2023 - 248 Redbud
I was quite surprised by the report , but also relieved . Although our redbud will finally give in to the decay , the remainder will not be prompt . And I was relieved that nearby plants were not in danger of catch a case of verticillium wilt . honestly , I learned a great business deal from this experience . There are a lot of fungal diseases out there , but if you protect your trees and shrub from accent , they will probably be able-bodied to avoid them . If you do discern a problem , take advantage of the diagnostic expertness usable from the university serve your extension office . You ’ll be beaming you did !
SOURCES :
Featured Photo : Redbud consider to have vascular streak dieback by Nicole Kopas , Va. Department of Agriculture and Consumer Services
“ Vascular Streak Dieback : An Emerging Problem on Woody Ornamentals in the U.S.,”VA Tech(Devin Bily , Plant Pathologist , Virginia Department of Agriculture and Consumer Services , and Elizabeth Bush , Extension Plant Pathologist , School of Plant and Environmental Sciences , Virginia Tech , 2024 )
“ Eastern Redbud Tree,”The Garden Shed
“ Verticillium Wilt of Shade Trees,”Va . Coop . Ext / www.pubs.ext.vt.edu/450 - 619
www.youtube . VCE / Botryosphaeria Dieback – Common Plant Diseases in the Landscape and Garden
“ Botryosphaeria Canker and Dieback of Trees and Shrubs in the Landscape,”VaCooperativeExt./450 - 726
