[CANUFNET] Elms and breakage

Thu Jan 11 08:41:21 EST 2018

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> 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
>  
> From: CANUFNET [mailto:canufnet-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
> 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 I  Tel: 705.445.0422  I  Fax: 705.444.2327  I  Cell: 705.994.2059 I   www.envision-tatham.com
>  
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