[CANUFNET] To Mulch or Not To Mulch

[Stephen Smith]

We did soil tests before we started.  Salt is high because it's on the east 
side of a major highway.  Drainage was poor because the topsoil was stripped 
off 60 years ago to build the highway, leaving silty clay subsoil. Too wet 
in spring, concrete in summer. They told me to improve organic matter 
content and loosen the soil to improve drainage.  Soon I'll plough the chips 
under, subsoil the site, and seed it with a cover crop a let it sit a while 
again until we plant it up.

Never had a problem with mulch and nitrogen as long as it's not incorporated 
at root depth. The amount matters too, a little won't hurt even if it is 
incorporated. Even volcanoes can be OK if they pull the material away from 
the stems.

I grew leftover bare-root stock last year in 100% ground up woodchips, 
watered and fertilized regularly, and none of them showed any negative 
effect from the substrate. If longer than 1-2 years it might start to show 
negative effects.

Gerard's response is the way to do things properly.  All the good planters 
do these things. Probably the difference between trained arborists and a 
low-bid landscaper doing the work.

Stephen Smith
Urban Forest Associates Inc.
www.ufora.ca

-----Original Message----- 
From: Anita Schill
Sent: Thursday, March 31, 2011 2:16 PM
To: Canadian Urban Forest Network
Subject: Re: [CANUFNET] To Mulch or Not To Mulch

You bring up a great point - what are te soil properties under the mulch?
compacted? clay? high in salts, etc. etc. There's a lot more factors that
are in play before we can say mulches a re good or mulches are not.

With regards to a previous comment regarding the nitrogen draw down from
mulch... This would happen if the mulch is incorporated into the soil but if
it is just on top? I don't think that should happen. Any other comments on
this?

Anita Schill, PAg
RCA #421
________________________________________
From: canufnet-bounces at list.web.net [canufnet-bounces at list.web.net] On
Behalf Of Stephen Smith [ufora at idirect.com]
Sent: Thursday, March 31, 2011 8:01 AM
To: Canadian Urban Forest Network
Subject: Re: [CANUFNET] To Mulch or Not To Mulch

We mulch heavily when we can.  It keeps the weeds down and moisture in.  The
only drawback is on wet sites that become wetter with a blanket on them.
Have a look at the attached doc from one of our projects.  The goal was to
improve the soil by mulching heavily and letting it rot in an old field with
hard clay soil. All we did was put mulch down and wait 2 years.

Stephen Smith
Urban Forest Associates Inc.
www.ufora.ca<http://www.ufora.ca>

From: Philip van Wassenaer<mailto:pwassenaer1022 at rogers.com>
Sent: Thursday, March 31, 2011 9:47 AM
To: 'Canadian Urban Forest Network'<mailto:canufnet at list.web.net>
Subject: Re: [CANUFNET] To Mulch or Not To Mulch

I agree that the organics are very important as well protecting the fine new
roots we need to encourage.

Mulch is good. Bad mulching practices are bad!


Philip van Wassenaer, B.SC., MFC
1248 Minnewaska Trail
Mississauga, Ontario
Canada, L5G 3S5
Tel:  (905) 274-1022
Cell: (647) 221 3046
Fax: (905) 274 2170
[cid:A551261B7B4C48A09D497BE9346F6098 at StephenSmithPC]

www.urbanforestinnovations.com<http://www.urbanforestinnovations.com/>




From: canufnet-bounces at list.web.net [mailto:canufnet-bounces at list.web.net]
On Behalf Of Jack Radecki
Sent: Wednesday, March 30, 2011 5:29 PM
To: 'Canadian Urban Forest Network'
Subject: Re: [CANUFNET] To Mulch or Not To Mulch

These new findings contradict my 35 years of experience in the field and
monitoring tree growth throughout. Perhaps  they are talking about mulch
volcanoes or excess mulch over the root zone. I have only seen the benefits
and the proof is the resuts that I have seen over many years.
Ask yourself the questions about how organic matter is replenished in a
forest? Trees "feed" themselves from their own litter. Without the mulch you
put the tree into an inorganic, inert world and prone to the many problems
that we are aware of, drought obviously is the main killer of young trees.

Jack Radecki Registered Consulting Arborist 342


From: canufnet-bounces at list.web.net [mailto:canufnet-bounces at list.web.net]
On Behalf Of terri smith
Sent: March-30-11 12:49 PM
To: Canufnet Canufnet
Subject: [CANUFNET] To Mulch or Not To Mulch

I would like to know if there are any municipalities that have stopped
applying mulch on newly planted boulevard trees.  Current research indicates
that mulch should not be placed over the root ball because it causes roots
to grow up into the mulch area, it also causes roots to remain within the
root ball area instead of growing out laterally, and it actually prevents
the water from penetrating deep into the soil.  Dr. Ed Gilman and Dr. Hannah
Mathers both agree that no more than 2 – 2.5 inches of mulch should be
applied outside of the root ball area (if mulch is still going to be
applied) and both are in agreement that mulch provides no benefit to the
tree.  At 2 inches of mulch there is little to no weed suppression.

These new findings contradict our current mulching practices and have
created much debate within our department.  I would like to hear from other
municipalities that have either discontinued mulching or have never mulched
their blvd trees.  Is there a need to increase the amount or frequency of
watering?

Terri Smith
Urban Forestry
City of Saskatoon