[CANUFNET] Tree maintenace

[Kuta, Gerry]

Data from some older cities may be approaching a point now whereby the
life expectancy of any given older planted street tree can be better
predicted. Historical data may factor greatly into this prediction and
would likely include conditions when the tree was planted, recent
traffic flow changes and any major construction work done around the
tree that would limit the tree's ability to perform to its full
potential. 
In Winnipeg most of our "old" boulevard trees, located in well
established neighbourhoods, were planted in 1920 - 1930 and are now
about 100 years old (mostly American elm). In their lifetime these trees
have "seen" roads being paved, the disappearance of the horse and buggy,
sewer and water line trenches, natural gas trenches, the introduction of
automobiles, salt, use of various chemicals, increased building and
associated micro climate change etc. I'm sure none of these, and other
local "improvements", are what the tree was waiting for.
Proper historical pruning in these areas has undoubtedly helped our
trees survive into 2008 and what Anita has mentioned here is absolutely
the best advice for older maturing trees. The pruning of only wood which
is dead will likely help the trees survive during their remaining years
and reduce any potential branch failure hazardous situations.

Gerry Kuta
Winnipeg 

-----Original Message-----
From: canufnet-bounces at list.web.net
[mailto:canufnet-bounces at list.web.net] On Behalf Of Anita Schill
Sent: September 17, 2008 9:49 AM
To: Canadian Urban Forest Network
Subject: Re: [CANUFNET] Tree maintenace

Alex Shigo covered this during his workshops in Boone, NC. Basically old
trees have a lot of mass with limited energy to support that mass. What
it can no longer support it sheds. We do not know which branches the
tree decides to shut down until the following growing season - what we
see as dieback. That should be the only thing that is pruned and don't
do any pruning until the leaves on the tree have fully expanded. Don't
prune anything else. Do not fertilize. Do everything you can to improve
the opportunity for photosynthesis as that will allow the tree to
produce and store more food. Usually this means soil aeration (reduce
compaction) and water (infiltration and drainage). Fertilization with
nitrogen is not recommended unless you know there is a deficiency. If
so. fertilize at a third of the rate and only fertilize when the leaves
are fully expanded. It is better though to improve your root
environment, including high quality organic matter that is full of
biology that can associate with tree roots (mycorrhizae). One of the
best ways to do this is allow the leaves to accumulate at the base of
the trees as a mulch. You do not need to add micorrhizae. They are all
ready there but they too need water, oxygen, organic matter and a proper
pH. Avoid root damage....
my two-bits,
Anita Schill
Calgary, Alberta
________________________________________
From: canufnet-bounces at list.web.net [canufnet-bounces at list.web.net] On
Behalf Of Listar, Ivan [ilistar at london.ca]
Sent: Wednesday, September 17, 2008 6:02 AM
To: canufnet at list.web.net
Subject: [CANUFNET] Tree maintenace

The City of London is conducting a UFORE analysis this year.

We are trying to raise the importance of tree maintenance, especially
pruning older trees.  There is a lot of general information about the
benefits of pruning but I couldn't find anything specific with to how
much longer (years) we can keep trees alive and maintain our canopy
cover through good pruning practices.  Does have any information on this
or could you point me in the right direction?

Thank you

Ivan Listar, R.P.F.

Urban Forester, City of London

A.J. Tyler Operations Centre

663 Bathurst St.

London, Ont.  N5Z 1P8

Phone: 519-661-2500 ext. 4977

mailto:ilistar at london.ca

fax: 519-661-2352