Thanks for that Al. Very valuable information this !!!

Yes, Al, very helpful demonstration!

Makes me want to go out and pinch a couple of my maples....but it's still a bit early in the morning ;-)

Josh

My pinch project for the weekend :-)

Much to do!

I nipped off about 30 growth points, and will repeat throughout the Summer.

Josh

I pruned all the already mature trifies last year when I got mine, now I'll take care of the new ones.

Rob

Looks like I have some fun work to do..I have over 8 of them and never knew of this..Thank you Al...I hope they can look nice and compact this season)

al, can you explain what trifurcation and bifurcation is? i have searched trying to learn, however haven't found much at all. very much appreciated!

Kim, it's when three or two branches, respectively, emerge from the same node on a plant.

Josh

Great info here. I usually chicken out pinching so early in their budding stage. Mainly because of fear of a sudden frost. Now if only I could be a little more organized and clean out my shed so that I can shelter them properly.

One question: Would you do this for maples or other deciduous plants that are still too young and need to thicken up? I have seen many youtube bonsai videos where they let a few selected branches grow unhindered to fatten up the trunk or heal a large wound. What most do not say is how they treat the rest of the plant.

toc - You want to prune/pinch trifurcations; because if allowed to grow it will cause the branch to bulge at that point. If it's a sacrifice branch, you needn't waste your time.

Rob

Would you do this [early pinching] for maples or other deciduous plants that are still too young and need to thicken up? Because the fewer corrections you need to make on the branches that are ultimately destined to be a part of the end product, I'd be careful about how that branch grows and looks, so it's a 'yes' for branches I'm planning to keep and a 'no' for branches that are ultimately destined to be contributions to the compost pile when 'sacrificed' after having served their purpose. To some degree, I also prune these sacrifice branches so they grow in such a way that they don't shade any of the branches I plan on using as part of the composition. I prune ALL growth off that is occurring close to the trunk & leave all the growth toward the end of the branch or main stem if that's what I plan to sacrifice.

Al

Makes a lot of sense. I will be happy when pruning and shaping a plant becomes a second nature. Not there yet.

It's funny ....... the decisions I make about where to prune are virtually automatic at this point. It takes much, much longer to get the scissors or other cutting tools into a position appropriate to make the cuts than to figure out what needs to be done. One of the most rewarding parts about bonsai is building the vision of a tree in my mind and then deciding what needs to be done today to bring that vision to fruition many years down the road.

Al

Al,

My biggest JM (2" trunk at the base) is opening buds right now. Several sets of buds could be ready to pinch in a couple days.

Last month I pruned almost every branch to the first internode except for a few leaders and removed all trifurcations.

Two days ago I root-pruned it because the roots were pot-bound and to replace the soil. 2/3 of the roots were pruned off.

Should I pinch the tree if I don't even know what branches I want to keep later?

Is there a benefit to pinching if it is not a goal to keep a Japanese Maple intentionally (Bonsai) small? I recently bought several small varieties for my patio container garden, but I want them to reach their full (small) size.

I also have a mature size Red Dragon planted in ground. Is pinching a benefit there?

Is there a benefit to pinching if it is not a goal to keep a Japanese Maple intentionally (Bonsai) small? Absolutely. There is no way to get this type of ramification (branch/leaf density) w/o pinching:

..... and pinching is something that is best started early on in the seedling stage.

If we're using actual growth of a plant as the metric by which we measure success, we do ourselves an injustice as it gives over much of the tree's potential eye appeal to the whims of nature, which invariably sides with the hidden flaws. Ask yourself if you're willing to sacrifice the trees future eye appeal on the altar of celerity.

In autumn after leaves fall, pinch/prune all branches back to 1 or 2 pairs of buds. As soon as the first pair of leaves emerge come spring, pinch out the central branch leader. I often use tweezers to separate the newly emerging leaves so I can get at that leader as soon as possible.

Also, take care to avoid multiple branches that form from redundant buds at nodes. They destroy the plant's eye appeal. It's not uncommon to see a dozen branches all emerging from a single node site that should have a maximum of 2 branches + the central leader that passes between the 2 branches.

Pinching out the central leader in the image forces new buds to emerge and grow from the axils of the 2 leaves that remain. Pinching out the leader also significantly hinders extension of the internode immediately proximal to the leaves in the image. THEN, when you repeat the process after the new branches appear by pinching out those central leaders, the internodes will be much shorter and the leaves smaller; whereas, if I had not pinched this new branch when I did, the internode proximal to the pair of leaves would have been much longer (2" or so), the next internode much longer (perhaps 4-6"), and the next internode as long as 12".

The following images were taken today, and the tree is genetically the same as the one above (first image in this post).

Here, you see 3 pairs of nodes within 1/2":

And here you see 4 pairs of nodes within 5/8". There are 2 nodes at the branch apex, but I had removed one of the leaves to help slow down growth of the branch. Partial defoliation is a technique used to manage the flow of energy in the tree. Defoliating/ partially defoliating strong branches ensures weaker branches (usually lower on the tree) which need thickening to look natural, get a greater share of the tree's energy.

Below, note how much a bonsai practitioner can reduce the size of leaves by judiciously

employing methods of increasing ramification and decreasing leaf size. Remember, these trees are both cuttings from the same tree.

Same tree as immediately above at the very beginning stage of increasing ramification and reducing leaf size.

Al

Some follow up questions: In your graph paper you allow for bifurcation by pinching out either the central leader or one of the side leaves. You seem to default to the central leader in describing what you do. If I pinch one of the side leaves, does that allow for more outward growth by the leader? And if I miss some trifurcations, do I get some big and some small leaves?

I pinched a half dozen maples yesterday. What I try to do is: when the branch buds are opening and first leaves start to unfold, I pinch out the central leaded from every branch I'm not purposely trying to thicken.

Once this leader is pinched out, extension of that branch is terminated, growth of the internode is significantly curtailed, and 2 new branch buds will develop and start to grow from the axils of the remaining leaves. Then, when the 2 new branches start to extend, I repeat the process. This keeps the tree very compact/full, and as you've seen it reduces leaf size and reduces internode length, both highly desirable for potted trees.

Sometimes, I remove 1 side bud on one side, allowing the central leader to grow, then remove a bud from the opposite side (or top or bottom) before terminating the branch just beyond a pair of buds. The branch in the image had 6 buds at the branch terminus. I scraped off all but 2. It is very important to remove these buds as soon as they appear. It isn't unusual to see potted maple trees with as many as 10-12 branches all growing from the same node. This destroys the appearance of the tree IMO.

The main reason to terminate the leader after the first pair of leaves is, the second internode is going to be LONG - I mean really long, like 5-8" long in many cases.

If I pinch one of the side leaves, does that allow for more outward growth by the leader? Don't forget that all the buds on the plant in the spring are BRANCH buds, so you're not pinching a leaf or leaves, you're pinching out the branch's apical meristem. Each bud will open and start to extend, with the extension growth occurring just proximal to the branch tip, at the apex/ apical meristem. And if I miss some trifurcations, do I get some big and some small leaves? No. there might be some variance in leaf size throughout the canopy, but that is a function of the tree's energy flow. Usually, when I see a large leaf, I simply remove it. This reduces the amount of energy being made in the branch, which decreases leaf size.

Al

I did all the pinching this year on my japanese maples as we discussed. I am wondering though if in the future I should instead allow the plants to grow as much as they want while young to get more size and trunk thickness. Maybe once larger, then start pruning and pinching? I am asking because it seems that even though I got a more full look with pinching, allowing it to grow would have gotten more leaves, more sap and more maturity faster. These are not bonsai, I am just container growing them until larger and will then plant them around the house. I got the idea though from a bonsai video where it was suggested to let the tree grow wild for awhile before pruning.

@chamaegardener, I grow ALL my collection of Japanese maples in containers and the only pruning I undertake is the removal of dead or damaged wood. Fullness of the canopy develops on its own with routine container care and regular fertilization. But I have no intention to grow mine as bonsai subjects other than the necessary repotting and root pruning required to maintain a healthy container subject.

Several of my trees are more than 20 years old.

Thank you GG. Am I right to think I will get better growth in containers while they are young, by babying them more with better soil (5-1-1 or gritty mix), more regular watering, and better placement for sun than growing in the ground right away?

I would not say so necessarily :-) I think much will depend on the age and size of the maple in question and your specific inground growing conditions.

Sizes are 1 gallon and 3 gallon. Small. If I am not necessarily getting better growth in a planter, then I may just plant them out in the spring following acquiring them and be done with it, except for those I want to keep on the patio. One planting area is mostly clay, with compost and mulch added over the years. The other is a garden bed I made by amending in a lot of pine bark fines and compost into the clay, which raised the bed about 18".

Japanese maples are hardy trees despite their often delicate appearance, so they don't need much in the way of special care. I have grown maples in the ground that put on an inch of trunk caliper per year, and I can't get even half that in a container, no matter how diligent I am about care.

There is no question that allowing a tree to grow wild (unfettered by pruning) results in more everything in terms of growth, o/a mass, extension, ..... I just find that taming trees that can send out shoots with internodes 1-2 ft long is a good idea unless you have unlimited space.

There is no reason to think maples must be pinched while young, but at some point you'll want to contain containerized trees, as you probably don't want 6 ft long branches sticking out from the basic outline. I like to take the extra time because pinching because it gives me much greater control over the end product. If you prefer, let them grow wild until the trunk is as thick as you want it, then prune back the top and all branches back hard in autumn after leaf drop - the branches will (should) be stubs from 1-3". If the tree was reasonably healthy just before leaf loss, tolerating the hard pruning is no problem. Starting the following spring, you can start building branches and the top.

Al

Thank you! Final question (probably not) is there a time in the season when I should stop fertilizing Japanese Maples in containers?

That "fertilizing late in the fall will force tender growth which will freeze" .... is a myth. Nitrogen plays no role in stimulating bud break. That honor goes to day length (actually the length of the dark period is the stimulus) and temperatures. Fertilizing late into the year enhances cold hardiness (more dissolved solids in cell solution to act as antifreeze [think salt[) and enhances enthusiasm of the spring push. You can fertilize right up until temps regularly start dropping into the 30s overnight, even after leaf loss (temperate deciduous trees). Roots continue growing strongly until soil temps hit about 36*, then slow to about freezing where they stop.

If anything, I would say withhold fertilizer in spring until the first flush of leaves have matured. This will help reign in the tendency toward long internodes after the very first pair of leaves on each branch.

I copied this from one of my old posts on a different thread - in case you have interest:

If you do a search using Japanese maples 14 degrees as the search words, you'll find that 14*f is widely considered and quoted as the lowest root temperature they will tolerate (not the 24* typo I listed above). If your trees were on the ground, you had the added advantage of the earth's geothermal heat to help keep root temps well above the 14* ambient temps. Even then, it's bad form to subject your trees to temps that low. Not all roots succumb to cold at the same temperature. The finest roots can be killed at temps as high as 28*, followed by increasingly larger and more lignified roots as temps fall. It's entirely possible that subjecting your trees to temps that low caused the loss of a lot of roots it would have been to the plant's advantage to keep, perhaps half or more - no way to tell w/o a look in early spring before buds move. Even then, root regeneration would be well underway. The end effect is to move the trees closer to cutting status than the well-rooted tree it was heading into dormancy. The end result is a tree that wakes up late in the spring because it was using a significant portion of its stored energy for root generation, which translates to a noteworthy amount of lost potential that can never be regained.

Al

I went tothis website showing soil tmperatures in my area north of Chicago along Lake Michigan.

Soil temperature got down to 12 degrees February 7, 2022, then down to a low of 11 degrees February 14, 2022.

Fall 2021 I bought one gallon size skeeters broom jm and rainbow jm. I sunk the pots into our garden for the winter. Those two made it but one other, I don't recall which kind of jm but it didn't make it. I did cover them with a layer of large pine bark nuggets.

I bought a mature red dragon in a box planter in fall of 2019 when my father passed and had it planted in our backyard. That made it. I would think the maturity of its roots would add some protection from death by 14 degrees.

Not doubting you, I think this means even planting jm in the yard in this area has risks.

That "fertilizing late in the fall will force tender growth which will freeze" .... is a myth.

I always thought about that and other fertilizer dos and donts. This one I had a gut feeling that it is a myth but could not find a good source of information. Thanks for clarifying that.

Can you recommend some good reading material on the topic of fertilizing to get a better understanding? Getting ready with reading material during winter.

Another example is suggested regimen of fertilizing conifers. For example, for Japanese Black Pine it is said that to fertilize well before bud break and then to stop it altogether after candle pruning in July or so. Is there any good reason for following these "rules" ?

I read a paper, a study on rhododendrons, with respect to effect of Nitrogen. In that paper they found out that N had no effect till about July in plant growth. After that extra N has helpful in increasing biomass. That was bit of a surprise to me.

Al, forgot to mention. Thanks for debunking the myth surrounding fertilizing in late fall.

Just yesterday I was talking to someone in our bonsai group why one of my azaleas does not flower at all. It is a different type for sure except I do not what is the type. But I got the standard answer - reduce N and increase P.

I've read it debunked several times, but I can't remember precisely where. Pruning too late in the season can force new growth which can often succumb to freeze injury, but even that is nothing more than a minor waste of energy. When we prune, new branches are forced to grow in leaf axils immediately proximal to the pruning cut. There is a whole row of buds in leaf axils, just waiting for a chance to grow. So even if the new growth freezes all the way back to its point of origin (leaf axil), a new branch will grow from the next axillary bud in line. The tendency for buds to remain dormant as the growth cycle progresses into fall is strong. Pruning now, in our zone, might not even activate buds proximal to the pruning cut; and, no matter how much N (or any other nutrient) you won't be able to trump the tendency for those buds to remain dormant until spring. I've actually consciously observed my own trees and see absolutely no inclination for late fertilizing to initiate buds that won't have a chance to harden off; and as noted, even pruning late in fall might not do the trick. There is probably a brief period of about 2 weeks that varies with geography and changes in weather during which after pruning, the growth won't have time to harden off and freeze might occur. On the early side of that 'window' the buds WILL have time to harden off, and on the late side, photo-period influence is likely to nullify the back-budding response.

Sorry about the azaleas - I haven't personally grown them, so I probably shouldn't comment. I know they like acidic soil and they are basally (as opposed to apically) dominant. If I had to guess, I would say that going to a 2:1:2 ratio fertilizer is all you need to slow vegetative growth, which forces the plant to put more energy into reproductive parts (blooms/fruit). I think I'd go that rout before I started to increase the amount of P the plant gets. Excess P can be a real issue for containerized plants. But- if you know the person to be knowledgeable and reliable, go with (s)he suggests.

Al