Keywords: Trees--Diseases and pests, Abies, Fungal diseases of plants
PAL Question:
Can I attempt to diagnose a diseased tree online? We're getting more brown spots on our grand fir and I would like to try to figure out what is wrong.
View Answer:
Try the Pacific Northwest Disease Management Handbook online---it has excellent photos. Search for fir.
There are several possibilities with brown spots as symptoms, especially:
*needle casts (there are 3 kinds)
*rust
*web blight
*current season needle necrosis
*shoot blight
*Grovesillea canker
*interior needle blight
Season
All Season
Date 2008-01-10
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Keywords: Sequoia, Abies, Burl
PAL Question:
I would like to remove a burl from one of my fir trees. Can I do this without causing harm to the tree?
View Answer:
I was unable to find any information on the incidence of burls (lignotubers) on fir trees (Abies), but I did locate information about redwood (Sequoia sempervirens) burls from The Sempervirens Fund:
About Redwood Burl
by Chris Brinegar, PhD
"The swollen tissue at the base of some redwood trees is commonly known as a "burl" although scientifically it is referred to as a lignotuber (from the Latin for "woody swelling"). All redwoods have lignotuber tissue but not all have large visible burls. Lignotuber tissue is derived from cells that exist in the tree's seedling stage and then proliferate near the base of the tree as it ages. Buds form within the woody burl and remain dormant until stimulated to grow by damage to the main trunk (usually by fire or logging). The resulting shoots grow rapidly using carbohydrates stored in the surrounding cells and minerals transported through the parent tree's root system. Lignotubers can also form their own roots.
Lignotubers are responsible for vegetative (clonal) reproduction common in redwoods. Without this mode of propagation, the redwood forest would appear far different than it does currently. The second and third-growth redwoods in our coastal forests were generated vegetatively after 19th and 20th century logging of the original forests. If redwoods were solely dependent on reproduction from seed, their numbers would only be a small fraction of what we see today.
Most people think of burl as the "sliced redwood" sold in gift shops and roadside stands, but they do not realize that many of these burls were obtained illegally. There is a growing black market for burl with much of it coming from unscrupulous dealers who harvest it from healthy redwoods on protected forestland. In some cases, removing burl can kill a tree or, at the very least, deface it and reduce its reproductive potential.
Burls can be planted under the appropriate conditions to allow the shoots to form roots and then grow into trees, but the typical buyer of a redwood burl places it in water, watches the shoots grow, then disposes of it after the shoots die from lack of nutrients. If you are determined to grow a redwood tree we suggest that you purchase a small seed-derived tree from a reputable nursery rather than trying to grow one from a burl that may have been acquired through questionable methods."
According to the information here, it seems that by removing a burl, you may risk harming or killing the tree. You might want to contact a certified arborist in your area, and ask them what they recommend. Here is a link to a list of certified arborists in the Pacific Northwest.
Season
All Season
Date 2008-02-07
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Keywords: Trees--Diseases and pests, Abies
PAL Question:
We planted a young Fraser fir last March. It has a lot of
new growth, but has developed some dead-looking tips here and there that
are a reddish rust color. I am wondering if we have a serious problem or
should I just remove the affected tips and not worry about it? I have
noticed a lot of trees this summer on my travels out through the
Cumberland-Enumclaw area that look a similar cinnamon color and are
totally dead!
View Answer:
The problem you describe could be the result of drought injury, or it
could be one of several rust and fungal diseases which affect fir trees.
Was the tree watered well after planting? Here is a link to information
on drought injury, from Oregon State University's plant disease database. Excerpt:
Drought injury usually progresses from the top of the tree downward and
from the outside to the inside of the crown. Top dieback and branch death
may be common. Defoliation of the mid-crown or loss of needles at the
base and tip of shoots can also occur in Douglas-fir. Older needles
commonly turn yellow and are shed prematurely. Roots may be alive even
though the entire above-ground parts are dead. Winter injury, gopher and
root weevil problems can produce similar symptoms.
Here is a link to the complete list of potential problems affecting firs.
Your description also sounds like the symptoms of Phytophthora, a fungal
disease which is common in our area. Excerpt:
Phytophthora root rot is usually a problem only in areas with poor
drainage or where flooding occurs. The fungus attacks the roots, which
rot and die. The infection moves up into the crown, where the cambium
(soft inner bark) turns reddish-brown or caramel in color instead of the
normal white to greenish color. Older trees may develop cankers on the
trunk, which are a dark reddish-brown when cut. The cankers may be
accompanied by split bark and oozing pitch. Lower branches wilt, turn
dark red, and die back. Younger trees are often killed outright, while
infected mature trees may show wilting, branch dieback, and/or gradual
decline.
Here is an image of Fraser fir suffering from Phytophthora.
The American Phytopathological Association provides additional information on this disease.
I recommend taking a sample of one of the cinnamon-colored branches to a
Master Gardener Clinic, and also taking photos of the whole tree, so that
you can have the problem diagnosed. If you are in King County, a link to clinic schedules may be found here is
the list of clinics. If you are near Enumclaw, the Pierce County Master Gardeners also have clinics.
Season
All Season
Date 2007-07-25
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Keywords: Abies, Chamaecyparis, Conifers, Dwarf conifers, Picea, Plant and garden societies, Tsuga
Garden Tool:
The Pacific Northwest is an excellent climate for growing evergreens because our winters are generally mild. We can grow far more species than just Douglas Firs and Red Cedars, and in city gardens dwarf conifers are much more suitable. Explore the wide world of conifers, plants that produce cones, by joining the American Conifer Society. Membership costs $25 per year which includes a nice quarterly journal with color photos. Their website has a database with descriptions and photos, as well as information on becoming a member. Call (410) 721-6611 to join.
Favorite four conifers as voted on by members of the American Conifer Society:
- Picea orientalis 'Skylands'
- Abies koreana 'Silberlocke'
- Tsuga canadensis
- Chamaecyparis obtusa 'Nana Lutea'
Season: All Season
Date: 2007-04-03
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