Method and season for pruning River Birch - Ask Extension
I have a clumping River Birch in SE Portland with one of the three stems not growing like the others. When we first planted this tree about 4 years ag...
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Method and season for pruning River Birch #817831
Asked December 28, 2022, 1:14 PM EST
I have a clumping River Birch in SE Portland with one of the three stems not growing like the others. When we first planted this tree about 4 years ago, the smallest stem had a dead terminal bud, so we cut it and now it is branching. i'd like to just prune this stem off and keep the two, but unsure about the best method and when to make the cut? Is now, in late December the best time or not? I've read different perspectives on when to cut these trees due to sap flow.
Thanks and Happy New Year
Multnomah County Oregon
Expert Response
Thank you for your question, Jay. The recommended time for pruning is late winter, while the tree is still dormant. Here is an extensive OSU article on the when, why and how of it: https://extension.oregonstate.edu/crop-production/fruit-trees/tree-pruning-basics
As for the three stems, I suspect the small one is a sucker, rather than a true trunk, which is common with this species. As the article explains, you can cut it and not impact the health of the remaining true trunks. I hope this is helpful. Good luck, and have a green 2023!
As for the three stems, I suspect the small one is a sucker, rather than a true trunk, which is common with this species. As the article explains, you can cut it and not impact the health of the remaining true trunks. I hope this is helpful. Good luck, and have a green 2023!
Hello and thanks for the reply,
The smaller stem I am referring to was originally the same height and width as the other two when we first got it. It isn't a sucker. Its just that it didn't produce any foliage after the first winter and the top half seemed brittle and dead. There was a small bud in the middle section of the stem growing out of the side, so I cut the stem off just above the bud and that's what we now have 3 years later. Doesn't seem like it will ever grow back to become a major stem like the other two, so I'm considering pruning it near the base.
Question - Is there a certain height I should prune to above the ground/root flare?
Thanks - Jay
Thank you for further information. When the leader (whether single or multi-) is pruned, there are no more growth hormones causing it to grow upward. The only hormones then active are those causing lateral growth, which is what your third stem has. In order to keep further lateral branches, you need to prune below a growth node. I am afraid the photo x2 is taken too far away, and no detail can be seen showing where the extant growth nodes remain. I have tried to enlarge it, but with no success. Either you prune just a few inches above the soil level, or you examine it to find a node. Alternatively, you can have a certified arborist visit to examine the tree and advise. This is a reliable website to find such a specialist: https://www.treesaregood.org/findanarborist/findanarborist
I am sorry I can't give you a more specific solution.
I am sorry I can't give you a more specific solution.
I have taken two closer photographs from opposite angles and hope this may help reveal any growth nodes near the bottom of the stem. I can understand if the bark makes it difficult to determine from a photograph.
Thank you for all the help.
Jay
Jay: much as I'd like to help, identifying a growth node requires scraping away the bark, and examining the plant tissue. Extension personnel are not allowed to make home visits. That's why I recommend an arborist.
Quite alright - much appreciated.
Good luck!
