Hello timespacette-ga!
In looking at past questions it seems that you?ve been dealing with
these Lombardy poplars for some time! I found a lot of information
about them, and it is readily apparent that they are trees with many
problems. I hope the information that I?ve collected for you is useful
in approaching your neighbor.
- - - - - - - - - - - - - - - - - - - -
HEIGHT AND GROWTH RATE
According to this online nursery, you can expect the Lombardy poplar
to grow at a rate of 6 feet or more per year! Some of their customers
report a growth rate of 9 to 12 feet per year.
http://www.cdr3.com/lombardy/
This nursery also describes the poplar?s growth rate as ?rapid, and
gives a conservative estimate of its mature height as being 40-60
feet.
http://www.naturehills.com/new/product/productdetails.aspx?proname=Lombardy+Poplar&ovmkt=6TL4TEQ1FFTRVQI52E5G63E95O
According to a tree information sheet created by The National Arbor
Day Foundation, the mature height is 70 to 90 feet, with a ?rapid?
growth rate. Incidentally, they are one of many organizations and
individuals to say that ?because of their disease problems, Lombardy
poplars are not recommended for planting.?
http://www.arborday.org/programs/TreeDiversityActv.pdf
Estimates of the maximum mature height for a Lombardy poplar vary from
40 to 100 feet, depending on the source. Here are a few websites with
their estimates.
http://www.backyardgardener.com/plantname/pd_7223.html
http://www.desert-tropicals.com/Plants/Salicaceae/Populus_nigra.html
http://www.davewilson.com/br40/br40_trees/br40shade.html
http://plants.nrcs.usda.gov/cgi_bin/plant_attribute.cgi?symbol=PONI
You can estimate how long it will take a poplar to reach its mature
height by assuming a growth rate of 6 feet or so per year. The EPA
states that its ?reproductive maturity? is reached in about 5- 10
years.
http://www.epa.gov/r10earth/offices/ecocomm/poplars2.pdf
- - - - - - - - - - - - - - - - - - - -
ROOT SYSTEM
The most commonly used descriptors when discussing the Lombardy
poplar?s root system are ?extensive? and ?invasive.? Many users on one
particular gardening forum complain of the ?far-reaching? and
?extensive? root system of the Lombardy poplar. Some report root
effects up to 30 feet from the tree!
http://forums.gardenweb.com/forums/load/rmgard/msg0220314420940.html?14
According to the USDA, Lombardy poplars require a minimum root depth of 32 inches.
http://plants.nrcs.usda.gov/cgi_bin/plant_attribute.cgi?symbol=PONI
The Lombardy appears on the list of ?Plants to Avoid? in Virginia?s
Suffolk County because of its ?extensive root system.?
http://www.suffolk.va.us/citygovt/udo/apdx_c/appendix_c9-1_plants_to_avoid.pdf
The Dave Wilson Nursery also describes the root system of the Lombardy
as ?invasive.?
http://www.davewilson.com/br40/br40_trees/br40shade.html
One strategy to keep the roots from spreading too much is to ensure
that the tree is watered adequately. This site also cautions against
planting Lombardy poplars near ?sensitive areas,? such as gardens or
walkways.
http://www.cdr3.com/lombardy/
- - - - - - - - - - - - - - - - - - - -
STUMPS, SUCKERS, AND ERADICATION
The USDA?s National Resource Conservation Service, on its online fact
sheet about Poplars, states that the Lombardy poplar does reproduce
through suckers (or ?resprout ability?), saplings that sprout directly
out of the roots, even in remote locations from the actual tree trunk.
http://plants.nrcs.usda.gov/cgi_bin/plant_attribute.cgi?symbol=PONI
Professional forester Steve Nix states that ?multiple suckers often
appear at the base of [Lombardy] trees and occasionally on roots far
from the tree, and the roots are considered invasive.?
http://forestry.about.com/od/silviculture/p/lom_poplar.htm
Removing a Lombardy poplar and its root system is seemingly quite the
task. On a question and answer site with Ron Smith, Horticulturist at
North Dakota State University, he states:
?The root suckers are coming from . . . the plantings [of Lombardy
poplars] and will continue to do so for years to come.?
To the question, ?Should we treat the stump [of a fallen tree] or have
it removed,? he says:
?Have the tree and stump removed. As the suckers come up from the
roots, spray them with a weed killer called TRIMEC. It translocates
quickly and will be effective in killing the roots.?
Another visitor to the site asks, ?We took your advice and cut down
nine huge [Lombardy] trees. The company that cut down the trees
removed the stumps and applied some type of chemical to supposedly
kill all the roots and trailers. Do you believe removing the trees and
using chemicals will take care of the problem or will we have to tear
up our yard in order to get rid of new growth? I'm having a hard time
believing that new trailers don't already have a good start and will
keep growing on their own.?
His answer:
?You are right to be a skeptic but, don't despair. Treat the suckers
that will be coming up with a broadleaf weed killer. Trimec, applied
two or three times this season, should take care of the problem.?
So in short, even after removing the stump, you will need to treat the
suckers with Trimec, or some similar product, to kill the broad root
system once and for all.
http://www.ext.nodak.edu/extnews/hortiscope/tree/poplar.htm
For more information on Trimec herbicide see:
http://www.trimec.com/
- - - - - - - - - - - - - - - - - - - -
WIND TOLERANCE
The main use for poplars, and Lombardy poplars in general is as a
windbreak. Most information I?ve found says that they are ?tolerant?
to wind, but they don?t usually specify how strong the wind has to be
before that tolerance is no longer effective.
Among the many fact sheets and informational websites discussing the
characteristics of the Lombardy poplar, here are a couple that mention
their use as windbreaks:
http://www.backyardgardener.com/plantname/pd_7223.html
http://rswcd.org/programs.htm
There are numerous references to the relatively short lifespan of the
Lombardy poplar. It is extremely susceptible to fungal diseases and
other infestations, leading to a hollowing of the trunk and subsequent
weakening. Theoretically this would present a greater risk to fall
damage when exposed to a strong wind.
http://hort.ufl.edu/trees/POPNIGA.pdf
http://forestry.about.com/od/treeplanting/p/bad_lombardy.htm
http://www.kiowacd.org/Products/SeedlingTrees/lombardy_poplar.htm
http://www.ameren.com/Environment/ADC_PlantingLargeTrees.pdf
For what it?s worth, one user of this gardening forum stated concern
about the fall risks of Lombardy poplars:
http://forums.gardenweb.com/forums/load/rmgard/msg0220314420940.html?14
Here is a quote from an article written in the South Manchester
Reporter. Apparently there was a fair amount of public opposition when
Manchester City decided to remove a number of poplars from a public
park area. The quote is from city arboriculturist Joe Walsh.
?Three previous trees in the area have already fallen. It has just
been fortunate that they have not fallen onto the dwellings, but it is
a 50-50 chance. . . . The life span of a Lombardi poplar is usually
about 60 years and they rarely die ?on their feet?. The nature of this
type of tree is that they become hollow in parts. In these particular
cases the likelihood of tree failure was full, they were close to
dwellings and were over 60 years old. This meant that they were
increasingly likely to fail [sic].?
Not scientific evidence, but it is another anecdote to heighten concern.
http://www.southmanchesterreporter.co.uk/news/s/78/78414_how_to_lose_friends_and_aggravate_people.html
- - - - - - - - - - - - - - - - - - - -
I hope that this information is useful in discussions with your
neighbor. A lot of groups are recommending against the routine use of
Lombardy poplars in general landscaping. Good luck! If you have need
of any further clarification, please let me know how I can help.
Sincerely,
Boquinha-ga
Search strategy:
Lombardy poplar tree
growth rate Lombardy poplar
Lombardy poplar maturity age
Lombardy poplar removal
root depth Lombardy poplar
"root system" "Lombardy poplar"
?Lombardy poplar? wind tolerance |
