Removing inner leaves

[Matte91]

Hello.

We all know the two techniques defoliation and partial defoliation.

I ones saw a guy removing all the inner leaves completly and then he cutted all the outer leaves in half. But I forgot why he did that. Have you guys seen that technique before? What are that technique used for?

Thank you.

 

[SWfloirda]

For some tropical trees, a ficus would be a good example, the old leaves will come off on their own eventually but they will look dull and maybe yellow for a long time before they shed so I will take the inner ones off myself sometimes. It helps to see the inner structure of the tree, allows more air circulation and it looks better. I've seen some videos where people cut the leaves in half but never understood what good it does so I've never done that myself.

 

[Shibui]

Reducing outer leaves outer leaves allows light to reach inner parts of densely ramified trees. That is supposed to help inner shoots develop and grow therefore keeping and promoting better branch structure. Some growers remove every second leaf, others cut all outer leaves in half, some selectively defoliate all outer ends but leave inner foliage intact.

Defoliating can sometimes stimulate shoots to grow from the dormant buds at the base of each leaf stalk. This works best when all foliage is removed as leaving outer and upper foliage can suppress new buds below.

My guess is that the grower you watched was using one or both of the concepts above. The trouble with many of these online posts is that we rarely see the results to determine if the techniques worked as intended.

Cutting part leaves does not seem to hurt either leaf or tree but it does reduce the amount of shade the leaves cause and allows air and sun to reach inner branches. It also reduces the amount of energy the tree can harvest from sunlight and therefore the food it can convert so that's one way to slow growth, reduce internode length, etc when we are trying to develop more compact ramification. Leaf cutting is just one possible technique in the bonsai tool box. There are other ways to achieve similar outcomes.

 

[Lorax7]

Hello.

We all know the two techniques defoliation and partial defoliation.

I ones saw a guy removing all the inner leaves completly and then he cutted all the outer leaves in half. But I forgot why he did that. Have you guys seen that technique before? What are that technique used for?

Thank you.

That’s very much counter to what I have seen from a number of credible bonsai professionals. Generally, one thins the outer canopy to let light in and takes care to preserve the smaller weaker leaves in the interior, as one of the key purposes of partial defoliation is to balance the energy of the tree, strengthening weaker branches and checking the growth of the strongest shoots.

I don’t know why anyone would deliberately weaken the already weak inner shoots by defoliating them and leaving the already strong outer shoots to grow.

 

[MrFancyPlants]

That’s very much counter to what I have seen from a number of credible bonsai professionals. Generally, one thins the outer canopy to let light in and takes care to preserve the smaller weaker leaves in the interior, as one of the key purposes of partial defoliation is to balance the energy of the tree, strengthening weaker branches and checking the growth of the strongest shoots.

I don’t know why anyone would deliberately weaken the already weak inner shoots by defoliating them and leaving the already strong outer shoots to grow.

I think it is different strokes for different types of trees. Ficus, I have heard, is more likely to back bud when a branch is left to run long. In my experience it does back-bud on bare wood where there hasn’t been a leaf in quite a while.
Also, you mention shoots where as OP is speaking generally. If I like a weaker, inner branch or shoot, I wouldn’t defoliate it, but may cut back to it.
JBP and Tsuga, tend to only backbud at the base of a needle or where the has been one in the past year or two, so preserving those inner needles can be important.

 

[Lorax7]

Also, you mention shoots where as OP is speaking generally.

Actually, I tend to use “shoot” and “branch” interchangeably most of the time. I’m a hobbyist, not a horticulturist or botanist, so my language may be a little imprecise.