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Gardening Answers Knowledgebase

Search Results for: Tree identification | Search the catalog for: Tree identification

Plant Answer Line Question

Keywords: Slope stabilization and soil erosion, Tree identification, Populus

When a cottonwood tree is cut down, does the stump die, or does it send out shoots that grow into more trees?

And, if a cottonwood tree located on a hillside is cut down, what is the risk of erosion?


As it turns out, some poplars and cottonwoods sucker from the roots and some do not. Determining what kind of cottonwood you have is the key to answering this question.

Identifying tree varieties can be tricky. The best way to get a positive ID is to take a sample to the Hyde Herbarium at the Center for Urban Horticulture (near the University of Washington). It is definitely worth a visit, as it is the only herbarium on the West Coast that serves the public.

Hours, driving directions, how to collect specimens, etc. are on the Hyde Herbarium page.

As for your second question, here is what the Washington State Department of Ecology's Vegetation Management: A Guide for Puget Sound Bluff Property Owners has to say (p.25):
Given the importance of tree cover on potentially unstable slopes and the advisability of retaining them for erosion control purposes, a landowner should explore alternative options to tree removal or topping...[if a tree must be cut] stumps and root systems should be left undisturbed...[to reduce the risk of erosion].

The above document is available online at http://www.ecy.wa.gov/programs/sea/pubs/93-31/intro.html.

A companion website from the Washington State Dept. of Ecology contains a great list of groundcovers, shrubs and trees that will help keep your slope intact if you decide to remove the cottonwood. The website includes a Plant Selection guide.

Date 2017-04-19
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Plant Answer Line Question

Keywords: Fungi and mushrooms, Forest products, Quercus, Tree identification

I am looking for advice on how to obtain an oak log or two. I got some shiitake mushroom starter plugs at the garden show in Seattle, and it seems that they grow best on oak logs. But I am having the hardest time trying to find one or two oak logs to plant them in. I've tried craigslist, and can't seem to find a thing. My tree identification skills are not exactly up to par, and I don't know the rules for cutting parts of trees in the forest, so I wonder if you have any advice for a novice mushroom grower. I really only need two logs, about 6 inches in diameter and maybe 3-4 feet long. This is proving to be a much more daunting task than I ever imagined!


Have you tried contacting Plant Amnesty? They maintain a list of certified arborists, some of whom will probably have occasion to prune or cut down an oak tree at some point. That might be one way of obtaining a log.

You might also try posting on the Pacific Northwest Garden Exchange (watch out--annoying ads!).

As far as cutting branches on public forest land, you should contact the Washington Department of Natural Resources before proceeding. They have information on harvesting and collecting forest products, and how to obtain a firewood permit.

Once oak trees have leafed out fully, they should be easier to identify. See the following tree identification guides:

Date 2017-04-13
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Plant Answer Line Question

Keywords: Pyrus, Malus, Tree identification, Prunus

Is it possible that I'm seeing cherry trees flowering this early (mid-February)? Some have white flowers, and some are pink.


It is certainly true that things are flowering early due to our mild winter this year. Last year, the famous cherry blossoms in the University of Washington's Quad began opening on March 13, and this winter has been warmer, so they may be opening earlier than that. While it is possible you are seeing flowering ornamental cherries (Prunus species), they are easily confused with their cousins in the same genus, flowering ornamental plums-- extremely common street trees in Seattle--most of which are definitely flowering now. Ornamental pears (Pyrus) are also flowering now. They have white petals, and might be mistaken for cherry trees as well but the distinctive odor of pear blossoms is a big clue to their true identity: acrid, astringent, and just plain stinky!

The Vancouver Cherry Blossom Festival offers some pointers on how to tell the difference between cherry and plum blossoms. Most cherry blossoms are not noticeably fragrant, while plums are. Cherry blossoms usually have small splits or indentations at the ends of their petals. Note, however, that the book Japanese Flowering Cherries by Wybe Kuitert (Timber Press, 1999) says cherry "petals are mostly [emphasis mine] retuse," that is, not all of them have a shallow notch or split on the ends of the petals.

Project BudBurst, a citizen-science phenology project, has information on identifying cherry trees. There is also a guide to telling the difference between cherry and apple blossoms (apple blossoms have 3 to 5 styles whereas cherries have one). According to the British Natural History Museum, one unifying characteristic of cherries is "flowers in clusters with stalks all arising from a central point, or arranged along a short stem, or in spikes."

Date 2017-05-12
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Garden Tip

Keywords: Tree planting, Tree identification

Trees are the answer! Or at least trees make our lives better by casting shade, cleaning the air and giving refuge to birds. It's important to find the right tree for the right place.

  • Great Plant Picks has selected plants that are proven performers in the Pacific Northwest. Complete profiles of all selected trees are available at their website www.greatplantpicks.org or give them a call to get their free booklet (206) 362-8612
  • Use SelectTree, a database from the Urban Forest Ecosystems Institute to select attributes that you want your tree to possess, such as clay soil, dry, resistant to verticillium wilt and fragrant flowers (that search suggested ornamental pear). Over 1,000 trees are profiled.
  • More tree information can be found at Virginia Tech Dendrology department fact sheet database, including a recording of the proper pronunciation of the Latin name. Over 800 trees are listed.
  • Friends of the Trees promotes planting trees in our cities to improve our quality of life. Their website also offers tree profiles and has a list of suggested trees for planting under power lines.

Date: 2007-04-03
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Garden Tip

Keywords: Tree identification, Trees--Diseases and pests, Trees--Care and maintenance, Trees

Silvics of North America Online by United States Department of Agriculture Forest Service, 1990.

Property owners with woodlots and tree lovers alike will find the Silvics of North America an informative and authoritative reference source on trees. Two hundred, mostly North American native trees are described including native habitat, associated trees and shrubs, propagation details, growth rate, and information on the major pests that may damage the tree. Many entries have information on the root development, which can be helpful in learning if a chosen tree will tolerate construction, or be appropriate for planting over water utilities.

Date: 2007-07-12
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May 31 2018 13:14:08