When/where to hard prune azaleas

[ShadyBonsai]

Hey guys so I’ve picked up a few azaleas over the summer. Grabbed a nice satsuki (attached image) along with a couple Hino. All of them have fairly straight trunks which I would like to develop further using a hard pruning method. I plan to grow them out for a few seasons in larger containers before i move them to bonsai pots. My question is where do I apply the hard prune - do I just chop the branches back or do I chop off the top entirely? In the image I would be looking to either cut the branches back at the blue lines, or chop back entirely at the red line. Also should I do this in late autumn or early spring? Finally, I seem to have mixed info on when to fertilize, should that be applied through winter or should I start up at the beginning of spring? Thanks for the tips!

 

[Shibui]

Azaleas will sprout from bare wood so you can chop anywhere you choose. That one is still pretty skinny. Do you really think it is ready for a trunk chop? Chopping will give better taper and options for trunk movement but will stop growth until the new branches grow to the size of the current crop. One is not right or wrong, just different ways to achieve similar outcomes however timing (years of development) may vary according to choices.
Larger containers for growth is a good plan.
Chopping the branches will still leave a mass of branches growing from the top of the trunk - prime conditions to swell the top of the trunk and create reverse taper.

Azaleas can be pruned any time of year. Prune in late autumn will not usually result in new shoots until the plant starts to grow in spring and will also remove any flower buds that are forming. Spring prune will grow back quicker.

Fertilizer is wasted if the plant is dormant over winter. Down here I fertilize through winter as plants are never truly dormant but I assume you have cold winters? Probably better to fertilize well through summer and hold off over winter and recommence in spring when growth resumes

 

[ShadyBonsai]

Oh man, thanks for pointing all that out! I’m definitely reaching information overload and mistakenly trying to skip steps. Now that you say it, no I’m not ready to trunk chop. I was watching some guys YouTube videos and he was talking about hard pruning every year to encourage growth but now that you mention the reverse taper his trunks were definitely all wonky and bubbled. It’s seriously difficult to find accurate bonsai information!

Ok - so I don’t have yard space to ground plant these, so I’m thinking of just upping the containers as needed. I guess a follow up question is related to the flowers. Ive been reading about flower removal on bonsai so they don’t cap their available energy, if I remove flowers while the plant is growing will it help it grow faster or will it not matter? Thanks!

 

[Shibui]

I have not done any tests to see if removing flowers makes a difference to growth rates. My gut feeling is that any difference will be marginal but flowers are routinely removed after flower peak to avoid setting seed which probably has a bigger impact on plant resources.
I always advise that development takes precedence over flowers so if it is a choice between pruning for future shape or to direct growth or having flowers for a week I know which way I would go. Flowers are transitory - there will be more next year. Good development lasts a lifetime.

 

[ShadyBonsai]

Great, thanks for the tips!

 

[Deep Sea Diver]

The first question I ask myself before chopping, is what’s my plan for this tree, and azaleas in particular as I’ve got lots of them that started off in the shape yours is in.

imo for azaleas specifically, Its better to see if there is anything left in the present structure of the tree already to give you a “line” and leave this intact. You can wire it to be how you like. Then before you cut, look for 1-2 complementary side branches to leave also. These branches may be temporary, or not, yet by doing so you save about a year of growing out and cutting back as there is a response in the azalea putting out buds when you keep the sap flowing through the trunk. It will also force you to plan the base primary structure right off, which gives you a clear goal for the tree Finally be absolutely sure to leave vegetation on the end of each branch.

In the past two years I’ve done a number of experiments with 2-5 year old azaleas this has shown to be the case each time time. Here’s a couple examples of 2 - 4 year olds.
.

Flowers - just as @Shibui mentions, energy savings comes from removing the ovaries which become the seed pod, as opposed to just removing flowers. Thus includes removing as much of the calyx as possible… shown in these images.


Fertilization - In the PacNW fertilization goes from late Feb -the end of Sept, with a halt the month of blooming. Some azaleas are prone to winter bark split if fertilized later the Sept. I use slow release Osmocote Plus with 1.5 - 2 weekly Miracle Gro & Humic acid for those in kanuma. Use less frequent fertilization for plants still in the peat/perlite nursery mix to avoid fertilizer burn.

If you do a severe cut back as shown above, it’s best to remove the flower buds in the late winter here when growing out azalea until the next year, except maybe a couple. Why…. Flower buds temporarily halt the extended growth of azalea stems.…. and then push out multiple extensions, splattering growth in all directions. Here’s an example of a whip left to bud on purpose as an experiment. You can see the kink on the stem? That’s where it budded. Then it sent out five new stems at the base of the bud, all but one were removed and the one left if is now the trunk. The upshot of this is that all vertical growth was temporarily stopped, then the energy was spread amongst all the new stems. For me it’s better to keep the energy going to growth.


cheers
DSD sends

 

[ShadyBonsai]

The first question I ask myself before chopping, is what’s my plan for this tree, and azaleas in particular as I’ve got lots of them that started off in the shape yours is in.

imo for azaleas specifically, Its better to see if there is anything left in the present structure of the tree already to give you a “line” and leave this intact. You can wire it to be how you like. Then before you cut, look for 1-2 complementary side branches to leave also. These branches may be temporary, or not, yet by doing so you save about a year of growing out and cutting back as there is a response in the azalea putting out buds when you keep the sap flowing through the trunk. It will also force you to plan the base primary structure right off, which gives you a clear goal for the tree Finally be absolutely sure to leave vegetation on the end of each branch.

In the past two years I’ve done a number of experiments with 2-5 year old azaleas this has shown to be the case each time time. Here’s a couple examples of 2 - 4 year olds.
.View attachment 387013 View attachment 387014 View attachment 387015 View attachment 387016

Flowers - just as @Shibui mentions, energy savings comes from removing the ovaries which become the seed pod, as opposed to just removing flowers. Thus includes removing as much of the calyx as possible… shown in these images.
View attachment 387020 View attachment 387022 View attachment 387021

Fertilization - In the PacNW fertilization goes from late Feb -the end of Sept, with a halt the month of blooming. Some azaleas are prone to winter bark split if fertilized later the Sept. I use slow release Osmocote Plus with 1.5 - 2 weekly Miracle Gro & Humic acid for those in kanuma. Use less frequent fertilization for plants still in the peat/perlite nursery mix to avoid fertilizer burn.

If you do a severe cut back as shown above, it’s best to remove the flower buds in the late winter here when growing out azalea until the next year, except maybe a couple. Why…. Flower buds temporarily halt the extended growth of azalea stems.…. and then push out multiple extensions, splattering growth in all directions. Here’s an example of a whip left to bud on purpose as an experiment. You can see the kink on the stem? That’s where it budded. Then it sent out five new stems at the base of the bud, all but one were removed and the one left if is now the trunk. The upshot of this is that all vertical growth was temporarily stopped, then the energy was spread amongst all the new stems. For me it’s better to keep the energy going to growth.
View attachment 387023

cheers
DSD sends

Oh man this is brilliant! Thanks so much for all this info, super helpful. I like some of the azaleas that have pretty chunky trunks - I understand that takes years to develop but will removing a good portion of the branches help develop that better/faster? Like leaving on some branches to help develop the taper of a single trunk, or is it better to leave more branches on to thicken quicker. I like what you did with your young plants they just look cool even at the smaller size.

 

[QuantumSparky]

The first question I ask myself before chopping, is what’s my plan for this tree, and azaleas in particular as I’ve got lots of them that started off in the shape yours is in.

imo for azaleas specifically, Its better to see if there is anything left in the present structure of the tree already to give you a “line” and leave this intact. You can wire it to be how you like. Then before you cut, look for 1-2 complementary side branches to leave also. These branches may be temporary, or not, yet by doing so you save about a year of growing out and cutting back as there is a response in the azalea putting out buds when you keep the sap flowing through the trunk. It will also force you to plan the base primary structure right off, which gives you a clear goal for the tree Finally be absolutely sure to leave vegetation on the end of each branch.

In the past two years I’ve done a number of experiments with 2-5 year old azaleas this has shown to be the case each time time. Here’s a couple examples of 2 - 4 year olds.
.View attachment 387013 View attachment 387014 View attachment 387015 View attachment 387016

Flowers - just as @Shibui mentions, energy savings comes from removing the ovaries which become the seed pod, as opposed to just removing flowers. Thus includes removing as much of the calyx as possible… shown in these images.
View attachment 387020 View attachment 387022 View attachment 387021

Fertilization - In the PacNW fertilization goes from late Feb -the end of Sept, with a halt the month of blooming. Some azaleas are prone to winter bark split if fertilized later the Sept. I use slow release Osmocote Plus with 1.5 - 2 weekly Miracle Gro & Humic acid for those in kanuma. Use less frequent fertilization for plants still in the peat/perlite nursery mix to avoid fertilizer burn.

If you do a severe cut back as shown above, it’s best to remove the flower buds in the late winter here when growing out azalea until the next year, except maybe a couple. Why…. Flower buds temporarily halt the extended growth of azalea stems.…. and then push out multiple extensions, splattering growth in all directions. Here’s an example of a whip left to bud on purpose as an experiment. You can see the kink on the stem? That’s where it budded. Then it sent out five new stems at the base of the bud, all but one were removed and the one left if is now the trunk. The upshot of this is that all vertical growth was temporarily stopped, then the energy was spread amongst all the new stems. For me it’s better to keep the energy going to growth.
View attachment 387023

cheers
DSD sends

Even just seeing your photos of those young trees makes me want to go back to the nursery and just buy a ton to experiment on. Were those all raised from seedling? My current issue is styling. All the nursery azaleas I have access to are quite large and there seems to be a limit to how much shaping I can do especially if I want to achieve the forms that you've shown yours in. Not to hijack the thread but I'm going through a similar thing. I chopped the heck out of one, and did extremely light pruning on the other. Not sure what direction i want to go with these, I'm just over here being happily lost

 

[Adair M]

Here ya go:

 

[Deep Sea Diver]

Oh man this is brilliant! Thanks so much for all this info, super helpful. I like some of the azaleas that have pretty chunky trunks - I understand that takes years to develop but will removing a good portion of the branches help develop that better/faster?

There are pros and cons to developing an azalea into a bonsai from seed, cuttings, young nursery plants, older nursery plants and yamadori.

Each requires multiple decisions and time. I work at all levels. Presently my favorite is making cuttings and growing out whips. This is the cleanest way to create a decent bonsai without any fits and starts. Yet it takes time. As you acquire older nursery stock or yamadori one ends up cutting off a year up to decades of growth and facing hard to overcome challenges, not the least embedded structural flaws and restoring natural taper. The former may never be solved, the latter usually takes years of growth and pruning to overcome if ever.

Like leaving on some branches to help develop the taper of a single trunk, or is it better to leave more branches on to thicken quicker.

IMHO When developing thunk thickness one trades off vertical growth. When working only on vertical growth one trades off trunk thickness. Both can be done at the same time however, but it’s a trade off, moderate trunk growth and moderate vertical growth, neither attribute develops as fast as working on just one aspect. The plus of this approach is that you are developing the design all at once, rather then in a piecemeal approach. It’s looks better and, to me, more fun.

So to answer your questions, it depends on your goal, which should be developed and refined starting with the very first cutback. This cutback should leave you with a clear avenue towards your primary structure, and maybe a bit of the secondary structure.

Its also my personal opinion that the scorched earth method of cutting an azalea back to an number of hurkey nubbins is counterproductive, wasting energy and time. (Except in the case of creating a clump design, even then, cutting back should be keep to the minimum needed). The tree ends up throwing off a plethora of small branches helter skelter in a desperate burst for survival. Next the operator using this approach goes ahead and cuts back all the growth they don’t want, growth the tree has expended energy on, further weakening the tree, to begin to create the makings of a decent primary structure.

Of course azaleas are tough, yet I feel a better way is to cut off only what you don’t need to establish your design, ensuring one leaves growth at the end of, or on each branch. This keeps the trees sap flowing going through the remaining branches, speeding growth producing nutrients etc into the exact areas you want growth.

I like what you did with your young plants they just look cool even at the smaller size.

Thanks, it’s pretty fun to work on the younger stock. I’ve about 30-40 youngsters going right now and am learning a lot.

cheers
DSD sends

 

[Deep Sea Diver]

Here ya go:

Gosh I’ve watched both Part 1 & 2 three times over the past year and have gone away with a not so good taste overall.

However, that said, much of what the operator does is good practice and should be listened to. imho he falls well short of doing a complete workmanlike job by the end. But there is a lot to be said for trying.

Also the example tree is one I would never have selected, however, as we all know, beauty is in the eye of the beholder!

cheers
DSD sends again.