Pruning Azalea in Autumn

[iconvoid]

I picked up this Korean azalea at a local nursery a couple weeks ago. I haven't done much to it except lightly prune to open up the interior.



I've been reading and video-watching about the John Geanangel approach to pruning azaleas, and from what I can tell from that, pruning it back now to my target length for primary branches would be a good idea--it won't harm the tree, and would save me having to wait 5-6 month to start developing the structure. It also seems like repotting it now is a fine option for azaleas, which again would save time in setting it on the path to being a bonsai. (And getting it in the right soil surely won't hurt).

What I want to probe is, does this advice hold true for both hardy and evergreen varieties? I had planned on wintering this guy outside this year. It's a poukhanense variant, hardy to Zone 4. (I plan to winter it deeply mulched, protected from wind under a stairwell landing that gets indirect light). First frost is somewhere between 5-7 weeks from now in Chicago. Is the Geanangel approach better suited to more temperate climes, or am I just as safe hard pruning and repotting in the Midwest?

All replies welcome, replies from people in similar climates with experience with this species especially valued.

 

[Jzack605]

The only adverse effect I can think of is they set their buds for the next season after they flower in spring. So you may not get flowering in the spring. Azaleas are actually rhododendrons.

This is likely not an issue for bonsai, but something to be aware of so you don’t think there is something wrong with your azalea come next spring.

 

[iconvoid]

The only adverse effect I can think of is they set their buds for the next season after they flower in spring. So you may not get flowering in the spring. Azaleas are actually rhododendrons.

This is likely not an issue for bonsai, but something to be aware of so you don’t think there is something wrong with your azalea come next spring.

Happy to forego flowers for a season if it means developing tree structure earlier. Thanks!

 

[Shibui]

I'm not sure about the varieties you grow over there but all the types we have access to here in Australia behave basically the same. Can be cut back at any time of year and will sprout new shoots all over bare wood. Can be repotted almost any time of year though they seem to respond better for me when repotted from spring through the warmer months while they are active.
many seem to think the flowers are more important than progress toward better bonsai and will delay pruning if it might reduce flowers for a year. I'm glad to hear that you are prepared to forego the brief enjoyment of flowering for a year or to to hasten shaping and development. This approach should yield a far better tree several years earlier than those who must have flowers.

 

[Mike Hennigan]

You are in a very different climate than John, and it is good that you’re keeping that in mind. There’s a number of things people do in the south that don’t make sense up north (not limited to bonsai ). That said I can’t give you an informed answer on azaleas specifically. I’ve not done a hard pruning on mine in the fall. But I will say that a hard pruning right now could severely lower your trees cold hardiness going into a Chicago winter and I would not advise it. The other thing is that you’re not actually saving 6 months in the development of your tree either. Your tree is going to be dormant those 6 months. You will get the same result (probably better result) in the same time frame as if you hard prune in the spring. And you’re tree will be alive. It’s not like your tree will be growing over winter. And I’m guessing that the growth response from a spring prune will be much stronger than if you cut now. Just my thoughts.

 

[CasAH]

@Leo in N E Illinois is the Chicago azalea expert. Let’s wait and see what he says.

 

[JudyB]

I would cast my lot with Mike H, it seems like you won't gain anything from doing this now with little time before the first frost. Although this is a more hardy species, if we get a very cold winter again, you might be setting the tree up for damage. I make sure that my Azaleas get the best spots in my overwintering setup to keep them from damage. If your recent pruning causes new growth I doubt it'll be hardened off before the frosts, so you may loose that in any event if it does grow now. Good luck!

 

[sorce]

What's up Chitown?

Lil late and maybe double but welcome to Crazy!

I'm with Judy. Cutting now won't necessarily cause new growth, but it will weaken the whole tree, and remove a lot of antifreeze making abilities.

I think your best bet may be to throw it in the ground before fall ends.

Unless you have a well protected (no rain) spot for winter.

What winter does to azaleas in nursery cans here kills them for me. Over and , well, I gave up before the last over.

Sorce

 

[Forsoothe!]

I respectfully disagree. Hard pruning now will give plants time to reassign secondary buds to primary at the new tips of branches and have little effect on winter hardiness. Over-wintering sunk in the ground is better for everything. Re-potting now is a bad idea. I only re-pot when plants are growing vigorously, like late spring and summer.

 

[iconvoid]

I respectfully disagree. Hard pruning now will give plants time to reassign secondary buds to primary at the new tips of branches and have little effect on winter hardiness. Over-wintering sunk in the ground is better for everything. Re-potting now is a bad idea. I only re-pot when plants are growing vigorously, like late spring and summer.

Unfortunately putting the plant in the ground is not an option, but I plant to keep it pretty well protected. We'll see!

 

[iconvoid]

FWIW, here are the threads I was referring to, suggesting (?) that azaleas can take late-season hard pruning and repotting.

Trunk chopping azalea

I've been told that it's best to wait until azalea are done flowering before bare rooting and trunk chopping. Is this correct?

www.bonsainut.com

Working with Nursery Stock

I have a couple of azaleas that were nursery stock and I’d like to start training them. They are a little overgrown and growing in 3 gallon pots. Where should I start working on these plants? Is it best to work on branches first, then roots after recovery or a little bit of both? Is...

www.bonsainut.com

 

[KillerButts]

Unfortunately putting the plant in the ground is not an option, but I plant to keep it pretty well protected. We'll see!

Can't speak from bonsai experience, but in my landscape experiences on large pjm and azalea, this type of work should be done in late April. After the spring rains and before the heat. I have had to do major restorative work due to a landscape "professionals" work over a 15 year period. I had to do structure work over 2 years before I could even think about proper form. I have done cuts now, June, march 20th and April 28. We prolly have many similar weather patterns in terms of blowing winter winds. I can promise you 2 things. 1 winter burn from fall cuts sporadically. Also rust from the previous fall spreading on late winter below cuts (not the new growth).

In late spring I have found the most vigor and generally an additional shoot aside from the avg 3. I feel this is optimum for back budding, and new shoots on dead heads or what's left below if you pinched. This will also help solid bud formation (sometimes doubles) for the next spring (pictured here). You will also give that new growth time to get some semihardwood but that's usually year 2 for me personally. Use of fish emulsion May 1st through August 28th has encouraged strong new growth. I have no clue if this will help but consider it. The final thing I do in April of year 2 of cuts is add m.o.a.b

On a much smaller scale I don't see a problem with expecting the same results. As long as you scale down. I bet you will get much better advice on your bonsai, but the above method should be tried. I also mulch with yew needles. I have found the mulches I have access to tend to be higher in ph. Also they like to breathe, most of my feeder roots sit only a inch below the soil. Thick (dead) hays and grasses should offer you better protection this winter. Seeing as it's small, throw em in the oven at 350 for a few minutes to kill any nasty first.

I have no degrees so take it with a grain of salt.

 

[KillerButts]

Before he was fired, and after the above practices.

 

[KillerButts]

Before he was fired, and after the above practices.

 

[JudyB]

I guess you need to determine for yourself if you are gaining anything or risking anything. Bonsai in pots are def. going to have a harder time thru winter than landscape plants in the ground. So I guess you can be patient or not and risk or not.