What is this tree? - Ask Extension
I noticed this small tree, very vertical structure, on a walk near my house. It is growing in a mostly shaded area with mostly native plants near a s...
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What is this tree? #869063
Asked May 18, 2024, 8:26 PM EDT
I noticed this small tree, very vertical structure, on a walk near my house. It is growing in a mostly shaded area with mostly native plants near a stream. I thought it might also be a native. My interest is that this might make a good plant for a back corner of my yard, shaded under my neighbor's fir trees. I don't recognize it, so I think I may need to search for a specimen to buy. Can you identify this tree?
Washington County Oregon
Expert Response
This looks a lot like one of the Sorbus. Maybe S. aucuparia, the European Mountain Ash. It's hard to be sure though. What does the bark look like? How is the overall plant shape (provide a photo from a greater distance).
You might need to wait for berries for a firm ID.
Go to the Oregon State Landscape Plants page I linked above, as you'll see on the right links for other Sorbus (mountain ash) plants. Some are native. You might want to visit area plant nurseries to see if any are for sale.
There are some specialty native plant nurseries with staff that can make recommendations for your area based on their inventory.
You might need to wait for berries for a firm ID.
Go to the Oregon State Landscape Plants page I linked above, as you'll see on the right links for other Sorbus (mountain ash) plants. Some are native. You might want to visit area plant nurseries to see if any are for sale.
There are some specialty native plant nurseries with staff that can make recommendations for your area based on their inventory.
Thank you for the reply to my question. In the photo the wood in the upper left is the truck of the tree.
The specimen has no significant side branches (yet) and is well over 6' tall, just from recall.
I will estimate the height later, probably next week to give it a chance to finish blooming to see the flowers better.
Hopefully I will remember to bring my phone for a second photo.
Ed
I took more photos as promised but forgot them for a week. The first photo (0256) shows the whole plant (maybe not the top foot), which I guess is about 14 ft. tall. I aligned the photo so the tree is backed by the middle tall italian cypress (I think that is right). The second photo (0257) is the same closeup as the first one I sent much earlier. The benefit that I see here is that you can see the small berries to help identification.
Note that if you confirm that this tree is an ash tree I have no desire to have it. Our street trees are 40+ year old ash trees. With the ash borer showing up locally I have no desire to accidentally bring the ash borer to the neighborhood. Thanks for your help.
Ed
This is one of the mountain ash trees. I’ll discuss which one, but first want to assure you the emerald ash borer will not attack a mountain ash, Sorbus aucuparia, because these are not true ash, (Fraxinus), so that insect isn’t a concern.
The next question is which mountain ash tree this is, and more specifically, which one you would plant on your property. The growth habit looks like this will be a straight, tall, tree, and leads me to guess this is European mountain ash, as natives are usually more shrub-like. The European species has berries hanging down though. Perhaps as they grow, these will tip down? It’s something you can watch for.
The page I linked above from Oregon State Landscape Plants for the European mountain ash, lists cultivars you may find for sale. There is concern in Washington about the plant invading natural areas. See a discussion with more links in this prior Ask Extension. For this reason, choosing a native seems best. Both native Sorbus are commonly called western mountain ash. Here are the two Oregon State Landscape Plants pages: Sorbus scopulina and Sorbus sitchensis.
Any mountain ash may get leaf rust, and some homeowners choose to remove a tree if badly infected. The rust moves between incense-cedars (follow this link for more information) and plants in the rose family, such as mountain ash. I’m not sure how to advise you about this though, as you won’t know until you try. However, if incense-cedars, apples or roses in your neighborhood obviously have rust, then avoid buying a mountain ash.
This turned into a longer answer than expected. I hope I’ve helped.
The next question is which mountain ash tree this is, and more specifically, which one you would plant on your property. The growth habit looks like this will be a straight, tall, tree, and leads me to guess this is European mountain ash, as natives are usually more shrub-like. The European species has berries hanging down though. Perhaps as they grow, these will tip down? It’s something you can watch for.
The page I linked above from Oregon State Landscape Plants for the European mountain ash, lists cultivars you may find for sale. There is concern in Washington about the plant invading natural areas. See a discussion with more links in this prior Ask Extension. For this reason, choosing a native seems best. Both native Sorbus are commonly called western mountain ash. Here are the two Oregon State Landscape Plants pages: Sorbus scopulina and Sorbus sitchensis.
Any mountain ash may get leaf rust, and some homeowners choose to remove a tree if badly infected. The rust moves between incense-cedars (follow this link for more information) and plants in the rose family, such as mountain ash. I’m not sure how to advise you about this though, as you won’t know until you try. However, if incense-cedars, apples or roses in your neighborhood obviously have rust, then avoid buying a mountain ash.
This turned into a longer answer than expected. I hope I’ve helped.
