[CANUFNET] Elms and breakage

Thu Jan 11 12:49:37 EST 2018

The issues with pear are clearly for poor nursery pruning that makes a heading cut to promote a tight canopy head and weak branch unions.  i have seen Bradford pears that were properly pruned in the nursery and they ave quite strong union, open canopies.  A valley forge elm that i started from a small hip and moved into a open landscape site developed a very wide spreading open canopy 9almost too open and wide spreading and i can see that the industry would want to prune that species hard to make a “better looking” tree but one with structural defects.  We have to always look at the nursery pruning (and root system) before writing off a species as a weak candidate.  The industry too often never thinks about the future health of the tree.

Jim Urban

> On Jan 11, 2018, at 11:35 AM, Naomi Zurcher via CANUFNET <canufnet at list.web.net> wrote:
> 
> It would certainly be interesting to know more about how we get to point B - trees that cannot survivie long term making it through the process - whatever that might be.
> 
> 
> On Jan 11, 2018, at 9:59 AM, shawnriberdy at yahoo.ca <mailto:shawnriberdy at yahoo.ca> wrote:
> 
>> Hi Naomi 
>> 
>> I'm not an expert in developing  disease free plant I also have never applied for funding on any research project but my guess would be that these cultivars are created from grants or funding for a research project. Then  the funding gets started to solve the issue that is causing the problems and then when that has been figured out the funding is stoped or has already been cut. The other issues that come up like structure and weak attachment is an issue that arises latter in the life cycle of the tree when the funding is already cut or is not the focus. Just my thoughts I'm not sure if anyone els has a more first hand explanation. 
>> 
>> Thank you 
>> 
>> Shawn Riberdy 
>> 
>> On Jan 11, 2018, at 5:41 AM, Naomi Zurcher via CANUFNET <canufnet at list.web.net <mailto:canufnet at list.web.net>> wrote:
>> 
>>> Hi ANderw:
>>> 
>>> Field experience is the very best research so appreciate your sharing as will be helpful for future reference.
>>> 
>>> Elms are not the only urban tree species that have had this issue. Pyrus calleryana 'Bradford" was a great tree for many reasons but notorious for falling apart with approaching maturity due to branch angle / included bark issues.
>>> 
>>> Do you have an idea why, when these cultivars are developed, this issue is not taken into account more often? What's the point in specifying trees that you know will fail with maturity? Better to never use and that is certainly a "no win" for the developer or the nurseries selling the species.
>>> 
>>> Wastes a lot of time effort and money.
>>> 
>>> Kind regards
>>> naomi
>>> On Jan 11, 2018, at 8:17 AM, Andrew Boyd via CANUFNET <canufnet at list.web.net <mailto:canufnet at list.web.net>> wrote:
>>> 
>>>> Hi Alison,
>>>> As someone who has been heavily involved in the work around Parliament Hill in Ottawa I can tell you that the predominant cultivar (clone) used has been ‘Liberty’ and not ‘Accolade’ (at least in the case of the elms planted adjacent to the US Embassy not far from the hill).  Like many elms developed in response to Dutch elm disease it seems they do have a tendency to form poor unions (in particular with included bark).  Ultimately of course this can lead to failure as the trees mature. 
>>>> On another recent project in Ottawa this was also an issue for a number of ‘Valley Forge’ trees, none of which were over 15cm in diameter.  From what I could tell in this instance they were victims of their own success - growing so rapidly that pruning couldn’t keep them in good form.  It sounds as though your clients are experiencing the same issue. 
>>>>  
>>>> Andrew K. Boyd, R.P.F.
>>>> Consulting Urban Forester
>>>> IFS Associates Inc.
>>>> P.O. Box 13593
>>>> Ottawa, ON
>>>> K2K 1X6
>>>> Tel: 613-839-0101
>>>> Fax: 613-839-0114
>>>> www.ifsassociates.ca <http://www.ifsassociates.ca/>
>>>>  
>>>> From: CANUFNET [mailto:canufnet-bounces at list.web.net <mailto:bounces at list.web.net>] On Behalf Of Alison Bond via CANUFNET
>>>> Sent: Tuesday, January 9, 2018 4:46 PM
>>>> To: canufnet at list.web.net <mailto:canufnet at list.web.net>
>>>> Subject: [CANUFNET] Elms and breakage
>>>>  
>>>> All:
>>>>  
>>>> At a conference in Quebec City I learned that much of the areas around the parliament buildings were being planted with Accolade Elm with good success.  After that conference we started incorporating elms into our street tree planting plans.  Accolade wasn't always available so there were often substitutions (Valley Forge, Princeton, Pioneer, Triumph.)
>>>>  
>>>> I have recently noticed that some of the elms (when reaching about 15.0 cm dbh) are starting to break apart and large branches are failing.  Many of these elms are vigorous growers and municipalities haven't been able to keep up with pruning to keep the form strong.
>>>>  
>>>> Has anyone else noticed this predisposition to breakage? 
>>>>  
>>>> Thanks.
>>>> Alison
>>>> 
>>>> 
>>>> Alison Bond BSc MSc BLA   OALA  CSLA
>>>> Landscape Architect and Certified Arborist
>>>>  
>>>> ENVISION-TATHAM Inc.   
>>>> 115 Sandford Fleming Drive, Suite 200, Collingwood, L9Y 5A6
>>>> abond at envision-tatham.com <mailto:abond at envision-tatham.com> I  Tel: 705.445.0422  I  Fax: 705.444.2327  I  Cell: 705.994.2059 I   www.envision-tatham.com <http://www.envision-tatham.com/>
>>>>  
>>>> This email may contain confidential and/or privileged information for the sole use of the intended recipient.  Any review or distribution by others is strictly prohibited.  If you have received this email in error, please contact the sender and delete all copies.
>>>>  
>>>>  
>>> 
> 

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