Growth response to pruning

[Wulfskaar]

I'm confused about something I keep reading... That with some trees, you get a growth response to pruning.

For the first time, this summer, I pruned back a coast live oak pretty heavily, and it responded with a lot of new growth. The others that I left unpruned grew maybe 4-8 inches, extending mostly only the leader. But when I pruned this one oak, I got 4-8 inches of growth on several branches. These are all about 4.5 years old.

Unpruned oak: 8" of growth on leader.
Pruned oak: 8" of growth x 8 = 64" of growth.

By pruning, it seems like I got a lot more growth. Does doing this add thickness to the trunk since it's actually growing more than if I didn't prune? Is this a thing or am I just making stuff up? If so, what other species react like this?

I didn't get a before pic.

Blue: Trunk and branches before pruning.
Red: Chop spot.
Green: New growth.

FYI: I plan to chop these back a lot more this winter. This was just an experiment, as I wanted to see how it handled pruning.

 

[nuttiest]

Is this a thing or am I just making stuff up?

Making stuff up.

 

[Wulfskaar]

Making stuff up.

So 8" of growth to 1 trunk > 64" of growth to several branches?

I'm open to me being wrong, but do you have any explanation as to why this theory is wrong? Trying to understand the mechanics of how this works.

 

[Japonicus]

Maybe this is why Walter Paul hedge prunes his maples. At least developing ones.

 

[cheap_walmart_art]

When you prune, you interrupt the hormone path between the roots and the apical buds - the ones at the very tips of the branches that are usually what elongate. When you interrupt that hormone cycle, the plant send those hormones to latent buds all along the branch behind the apical buds. Those buds then basically become apical buds and start elongating. This will build ramification in branches.

Trunk thickness can be achieved by elongating leaders. So pick a branch or the apex of your tree and let that grow unhindered. Trim and style the rest. I’ve had 10” tall pre bonsai with 5’ leaders before. Let it run, that thickens the base, chop it, do it again.

 

[Wulfskaar]

When you prune, you interrupt the hormone path between the roots and the apical buds - the ones at the very tips of the branches that are usually what elongate. When you interrupt that hormone cycle, the plant send those hormones to latent buds all along the branch behind the apical buds. Those buds then basically become apical buds and start elongating. This will build ramification in branches.

Trunk thickness can be achieved by elongating leaders. So pick a branch or the apex of your tree and let that grow unhindered. Trim and style the rest. I’ve had 10” tall pre bonsai with 5’ leaders before. Let it run, that thickens the base, chop it, do it again.

So it's more a function of lengthening/thickening of the existing sacrifice(s) and not overall growth of thinner shoots and new leaves?

8" of growth on a single existing sacrifice thickens the trunk more 8" of growth on several new shoots, even though it's less actual growth? Ok, I think that is starting to penetrate my thick skull, even though it feels counter-intuitive.

Thanks! I appreciate the input!

 

[nuttiest]

Just looking at this photo again where you cut,what was the decisions made there, why did you cut where you did (instead of farther) was there a small branch you liked, etc.
And B, did you have a percentage in mind. and C what month?

 

[Wulfskaar]

Just looking at this photo again where you cut,what was the decisions made there, why did you cut where you did (instead of farther) was there a small branch you liked, etc.
And B, did you have a percentage in mind. and C what month?

I have several oaks the same age in 1 gal pots.

This particular tree is one I've been experimenting with, while all the others have been left untouched. A couple years ago, I tried some wiring on this one to see how it would react to wiring a relatively thick and non-bendy trunk. It was basically a single long trunk. Ultimately, it worked, but I was not able to get a hard turn and it also peeled some of the bark off.

So, this year, around April or May, I decided to prune off a big part of the wired/bent trunk as well as 2 of the longest branches/trunk that grew out of the main trunk that was wired down. I had read about inducing more growth by pruning, so I wanted to see what happened.

What happened was an explosion of new growth at all the leaves just below the cuts. Buds from the base of the leaves shot out new shoots within a couple weeks. I have since even pruned those back a bit to again see growth (and ramification) from those secondary cuts.

In January/February, I plan to prune well below the places I pruned a couple months ago in order to add movement to the trunk in a clip-and-grow fashion, rather than using wire. As you can see in the pic, those branches are super straight and long. They must go eventually.

tldr: I've been experimenting with this tree. Just trying to learn hands-on how coast live oaks react to things. Also, I don't mind having a smaller bonsai in development while I let the others grow.

 

[rockm]

Hard pruning older wood improves ramification dramatically. The response can be manipulated to varying degrees to fine tune branching and design needs.

Lignified (woody) tissue is best to prune since it has developed those resting buds that are “told” by interrupter hormones to grow. Route of thumb is The greener the stem the less the backbudding. The woodier and old the branch the more you generally get. This can vary with age and species

 

[nuttiest]

So, this year, around April or May, I decided to prune off a big part of the wired/bent trunk as well as 2 of the longest branches/trunk that grew out of the main trunk that was wired down.

Wiring things down to make new leaders and preserve the existing leaves is good for conserving energy, but normally a cut,,,. we know if you prune a tree you are trying to build up, everything you cut off is less to manufacture food for the trunk. But you are saying it is bushier than the other 2 at summertime, then you are making more energy with tree 1 and if there is indeed more leaf area, then you would be building trunk faster than the other 2 at this point forward. You must have really hit the sweet spots on each branch to get more biomass than the others!

 

[cheap_walmart_art]

Th

So it's more a function of lengthening/thickening of the existing sacrifice(s) and not overall growth of thinner shoots and new leaves?

8" of growth on a single existing sacrifice thickens the trunk more 8" of growth on several new shoots, even though it's less actual growth? Ok, I think that is starting to penetrate my thick skull, even though it feels counter-intuitive.

Thanks! I appreciate the input!

Thats been my experience, yes.

 

[leatherback]

A single long whip generally adds more girth to the lower trunk than 10 shorter whips. What comes into play is also the mechanics of the tree. Morce on wood encourages the tree to build a stronger base. A long whip in the wind therefor really builds mass for strength, rather than just the girth needed to transport sap.

 

[Shibui]

By pruning, it seems like I got a lot more growth. Does doing this add thickness to the trunk since it's actually growing more than if I didn't prune? Is this a thing or am I just making stuff up? If so, what other species react like this?

Way back, one of the more experienced club members told me that pruning helped thicken trees because of the extra growth that pruning causes so you are not the only one to notice this and form the same conclusions. I have not done any side by side tests to either confirm or disprove the theory. Maybe you could take this on board and do some trials with accurate measurements over a couple of years. Some trimmed trees V some allowed to grow long.
Look forward to any results.

 

[oranjeaap]

I think "growth" is too much of an umbrella term to simply state that "pruning stimulates/inhibits growth".
There are different types of growth and they respond different to pruning, you should be more specific.

I think it's also not as black and white as ppl make it out to be.

I'm convinced that if you take 2 identical trees, and let one grow wild for 10 years, and prune the other for maximum ramification for 5 years and then leave it to grow wild for 5 years the result might surprise you.

 

[Wulfskaar]

Thanks, everyone, for the very interesting discussion! After seeing so much growth in the pruned tree, the question was bothering me. The consensus is that letting it grow will give it a fatter trunk.

I'll be pruning hard on this little oak in January or February 2026 again (when the new growth starts) and I'll leave at least one or two of the others to grow wild.

Theory 1: Maybe the growth response is an emergency response that uses up some stored energy, which will set back trunk thickening in the long run.
Theory 2: A long whip blowing in the wind increases trunk girth/strength by breaking tissue on a microscopic level that is then filled in with new tissue, adding girth over time.