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NEWisc
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American Mountain Ash (Sorbus americana)

Does anyone have any information on propagating American Mountain Ash (Sorbus americana) by cuttings? I've located a lot of information on seed propagation, but nothing for cuttings.

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Jess
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I cannot give you specific information of propagating from mountain ash but most trees are easy to reproduce from hardwood cuttings taken in the autumn.
You need to take mature wood (not soft tip growth, a nice whippy young branch is best) with buds ideally spaced 6 inches apart but slightly longer or shorter won't hurt.
Cut above the upper bud at an angle purely to remind yourself which end is up! Cut straight across just below the bottom bud. Plant in a pot spacing cuttings a few inches apart and push down about an inch so they are firmly held in the pot. Place pots in a sheltered position for the winter and forget about them.
Sometime around April the following year they should have produced enough roots to plant out. :D

TheLorax
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How about Sorbus decora propagation? I don't know anyone who has been successful propagating either species from cuttings. Not that it probably hasn't been done by somebody somewhere but propagation for both S. americana and S. decora is known to me only from seed. Now, there are people out there who have successfully grafted cultivars to appropriate stock so grafting will work but then you'll need the stock onto which to graft so you're back to propagation from seed for understock. I've grown S. decora from seed. It's actually a trickier seed and I suspect S. americana is going to follow suit. Place the seed in shallow containers where water can wick up to keep it damp not moist. Place these containers in a green house or bright window in your home where soil temps will remain at around 70°F for about 4 weeks. From there, go ahead and take your seed and wrap it in damp sphagnum and place them in a zip lock and cold stratify in your frig for around 3-4 months. When spring comes, take them out and plant them in containers that will allow for the tap root. You should get a germination rate of around 90%+ this way. You can winter sow this species as well.

I got 19 out of 20 to germinate as described above. I used 2-liter pop bottles with the tops cut off to start them and pro-mix.

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Jess
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TheLorax wrote:How about Sorbus decora propagation? I don't know anyone who has been successful propagating either species from cuttings. Not that it probably hasn't been done by somebody somewhere but propagation for both S. americana and S. decora is known to me only from seed. I've grown S. decora from seed. It's actually a trickier seed and I suspect S. americana is going to follow suit.
Apparently it is not possible from cuttings as this site shows. https://www.macphailwoods.org/nursery/partlist.html
I wonder why? What is it in some plants that stops them being propagated vegetatively? :roll: You would have thought that the more options open to a plant to the better.
Perhaps I should study botany and find out. Any botanists on here?

TheLorax
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I went and checked out my Dirr manual after I posted and he states it has been done for S. americana but provides absolutely no information on how and cites no research. Based on that, I'd be inclined to agree that there exists no "practical" means by which to propagate them asexually so the info at the site Jess found is good and solid.

Here's what I found for Sorbus spp.-
https://www.fs.fed.us/global/iitf/pdf/shrubs/Sorbus%20scopulina.pdf
Greene’s mountain-ash may be asexually reproduced using cuttings. Late-summer semihardwood stem cuttings 15 to 25 cm long and 0.3 to 1.3 cm in diameter are recommended. After hormone treatment, cuttings placed in a bottom-heated mistbed for 6 weeks yielded 47 percent rooted
cuttings (Luna and Wick 2001).
I did find numerous references to cuttings being almost impossible to root.

I'm not a botanist but I'll take a stab at why they might be extremely difficult to root using my trials and tribulations with oaks which are touted as being almost impossible to root. At least I've never gotten any oaks to root from cuttings. Seems as if there is a precarious balance that needs to be respected when using hormones. Don't use enough- they don't root. Use too much- basal tissue damage occurs which kills off your cutting. Now toss in all the other factors that can negatively impact the success of a cutting such as humidity, air circulation, and the medium chosen and I guess the nursery industry took the path of least resistance and decided to forgo taking up bench space to propagate certain species from cuttings that could be grown from seed more cost effectively. Not enough research out there for the "almost impossible to root" species because there's simply been no incentive to create same? That being said, I guess asexual propagation is possible but who can afford the time and expense to repeatedly "tweak" the clonal process to the extent that one can get consistent results. Sorry Jess, that's the best I can come up with.

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Thanks for all the help. I will have to try the seed approach when I try to propagate some more trees. My reason for trying to get some info on cuttings is that I have a small american mountain ash that is trying to form a double leader and I plan to remove one of the leaders. I was hoping to use the removed leader to propagate another plant. I'll just have to put it in some potting mix and try some experiments with it.

Miss Daisy
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Hi NEWisc,

Mountain Ash propagation by branch is extremely easy. I've done it a couple of times in the past, and again, yesterday with two other small branches.

My motto is: do or die.

Two Falls ago, I cut a small twig (maybe 2' high) from my main tree. Stuck it in the ground and left it alone. Now, the twig/tree is approx. 7' tall.

Yes, do experiment, you'll loose nothing. Take a few twigs, put them in the ground where you'll want the trees, and forget about them... except for watering of course :) You might want to keep a few rocks around it until they are established (to make sure the wind does not carry them away).

Other branches I've tried is from my black currant. They are extremely easy and produce very fast.

Hope this helps.

TheLorax
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Are you able to post a photo of the Mountain Ash you propagated from cuttings please? I'm thinking you might have Sorbus aucuparia which is European Mountain Ash. The European Mountain Ash roots well from softwood cuttings with or without rooting hormone.

There are people out there who claim to have rooted Sorbus americana successfully so I know I would have experimented if I was going to be pruning out a leader but then that's just me. I am sort of in with Miss Daisy from the respect that there's nothing to lose and they could just take.

Miss Daisy
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Hi TheLorax,

Yes, I'd be happy to post a pic. Will get one going tomorrow... and perhaps, even with me in the pic so that you may see how tall it is now.

The "mama" tree is at my zone 3 home (Northern Ontario). I will be there this weekend. I live in zone 5 (Eastern Ontario). I will also post a pic of the mama tree so that you may see the parental unit tree :))

I must correct something... I said two Falls ago, but looking back at my archive pics, I believe it was more in Fall 2005. Just the same, the results are fabulous.

If you google "American Mountain Ash", the pics you see there are exactly the tree I have.

If for some reason I am distracted tomorrow and do not post, don't panic, I will do so for sure before the end of the weekend :))

Miss Daisy...
... who's always willing to experiment with anything !!!

Miss Daisy
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TheLorax,

I just noticed you were not talking to me, but to NEWisc... hehehe.

Anyway, just the same, I will post a pic of my experiment :D

Miss Daisy

TheLorax
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I'm always willing to experiment with anything myself. I don't even care if it croaks on me.

The growth habit you described suggests you might have the European Mountain Ash even if you rooted it in '05. S. decora has a slower growth rate and S. americana is also slow but... if they like their new digs, they could conceivably both grow to your height in 3 years.

In winter, you can tell which is which easier. For right now, you might want to hold off on posting photos of your Mountain Ash until the leaves are fully developed and then maybe get some photos of the blooms which will follow soon after. The berries that come in fall are usually telltale if what you have can't be pinned down by the leaves.

I stuck a few twigs of weeping willow in the ground once on a lark and those rooted and took off like all get out. I really didn't think they'd do that. Got rid of the momma and the twigs I had stuck in the ground when I saw that. Didn't want any to begin with because they're very messy trees. I've got enough to do around here as it is.

Editing to add- just saw your other post. Was typing when you were typing-oops. It's your Sorbus I'd love to see photos of! If you pulled off rooting these, I want to try it again.

Miss Daisy
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TheLorax,

So sorry, I wanted to take pics tonight, but my new stove took priority :(((

I will definitely do so in a few days. I am going to zone 3 this weekend and will take pics of mama mountain ash. And then of zone 5 twig a few days later.

Have a nice weekend :)

Miss Daisy

TheLorax
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NEWisc-
The 4 year old plant on the left is a Sorbus decora from seed. It was re-potted two years ago.
The 2 year old plant on the right is S. americana from seed.
The 4 year old plants go in the ground this year. I'll cut off the 2-liter pop bottles and re-pot the 2 year olds and hang onto them for a bit longer before planting them out.

Leaf color means nothing, the younger plant will end up the same color as the older plant.

[url=https://good-times.webshots.com/photo/2610198000103590453RuNVeu][img]https://thumb13.webshots.net/t/66/666/1/98/0/2610198000103590453RuNVeu_th.jpg[/img][/url]

Buds on both are generally glabrous but can be ever so slightly pubescent. Leaflets on decora are less than 3x as long as wide and leaflets on americana are more than 3x long as wide. Git ur specs on and have a good ruler handy. Easiest way to tell those two apart is to feel the leaves. S. decora lateral leaflet undersides are glabrous while americana is slightly pubescent beneath.

Leaflet size differences-
https://www.uwgb.edu/biodiversity/herbarium/trees/sorame_sordec_leaves01web.jpg

Here's a close up of S. decora-
[url=https://good-times.webshots.com/photo/2673086700103590453jFfLCx][img]https://thumb13.webshots.net/t/69/469/0/86/70/2673086700103590453jFfLCx_th.jpg[/img][/url]

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