Hi everyone,


Sorry for the duplication of emails, I am sending this to two different (and probably overlapping) listserves.


I visited a nursery yesterday to examine some injured Hydrangea arborescense.  Photos are attached.  The third photo is actually of a weed growing in one of the pots (horseweed, or Conyza Canadensis).  The weed is also very symptomatic.  Please let me know if you have observed this injury before.  Here is some background information based on my site visit and interview with the grower:


·         The injury was uniform across the entire block of H. arborescense.  All three cultivars of the species were affected, even though they were in different locations throughout nursery (a very large nursery).


·         H. paniculata was not affected, despite being located immediately adjacent to the H. arborescense.


·         All of the affected plants were irrigated from the same water source (pond with captured and recycled water).


·         Weigelia were also stunted, but did not display these symptoms.  All other crops, primarily evergreens of some sort, were NOT affected.


·         All of these plants were potted this year, with liners coming from different sources.


·         Based on information from the grower, this was not 2,4-D, dicamba, or any other phenoxy or auxinic herbicide.  These products were not used on this location. 


·         They have agronomic neighbors, but again, the pattern was very uniform across very large blocks of plants at several locations throughout the nursery.  Drift from a neighbor does not seem to be responsible.


Any thoughts or opinions?  I am tracking down several herbicide-related possibilities with my weed science colleagues.  But I didn’t want to rule out other horticultural causes.  Please let me know if you’ve seen this type of injury before, and if so, what potential causes were identified.


Thank you,




James Altland

220 FABE Building


1680 Madison Ave.

Wooster, OH  44691



This electronic message contains information generated by the USDA solely for the intended recipients. Any unauthorized interception of this message or the use or disclosure of the information it contains may violate the law and subject the violator to civil or criminal penalties. If you believe you have received this message in error, please notify the sender and delete the email immediately.