Re: Canadian hemlocks

What a shame, Nancy.  I've had woolly adelgids on my hemlocks and
gotten rid of them with hort. oil spray.   Have to keep it up, tho'
as they tend to return.  With a tree that large, your Mom will
probably need to hire a service to spray it, since you have to hit
the little beggers to do much good.  And, they need to be controlled
or they _will_ kill that tree.  Fertilizer will not help the tree
and, as someone else pointed out, this is totally the wrong time of
year to fertilize a tree.  High nitrogen would only encourage new
growth which would not harden off and would be winter killed, adding
to the tree's stress.

There's a fair amount of info. on these pests on the web - here are
only a few of the sites devoted to it:

http://www.ext.vt.edu/departments/entomology/factsheets/hewoadel.html
(tells what concentration of hort. oil is needed for which months of
year)

http://www.state.ct.us/caes/FactSheetFiles/Entomology/fsen012f.htm
(which also points out that fertilizer is NOT what one should do for
a tree under adelgid attack!)


http://www.forestworld.com/forestry/outreach/pestalerts/hem_w_adelgid/
hemlock.html
(has pix of egg masses and damage done)

http://www.kevintree.com/hemlock.htm
(points out that " Control of 95-100% is common with the following
pesticides: horticultural oil, insecticidal soap, malathion or
diazinon")

Best of luck to your Mom on saving that tree.

Marge Talt, zone 7 Maryland
mtalt@clark.net
Editor:  Gardening in Shade
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Hemlock Woolly ----------
> From: Nancy Stedman <stedman@RCN.COM>
> Date: Friday, August 18, 2000 10:40 AM
>
> I just spent a few days working on my mother's garden in Cape Cod,
a fairly
> mild climate even though it is north. My mother has a once-gorgeous
Canadian
> hemlock with at least a two-foot wide trunk. The tree has been
attacked by
> woolly algelid (not sure I'm spelling that right). My mother wants
to "help"
> the tree by fertilizing it with Scott's evergreen fertilizer, which
has a
> nitrogen ratio of about 33. I tried to convince her that she'd be
making a
> mistake, but to no avail. Can anyone come up with some compelling
reasoning?
>
> Her garden, by the way, has gotten out of control and is a good
argument in
> favor of *not* planting ajuga unless you are a vigilant sort of
gardener.
> The ajuga develops holes, giving a foothold to weeds, and then runs
into the
> lawn, where it is difficult to pull out without also removing turf.
>
> Nancy S.
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