How much foliage removal on juniper?

[Joe Dupre']

I'm working on a decent sized shimpaku juniper and have been watching YouTube videos on styling. I've seen people cut off what appears to be 70-80% of the branches and foliage in the styling process. I've always read that junipers really depend on their foliage. What gives? I'm curious on your experiences and research on survival rates on such aggressively pruned junipers.

 

[Paradox]

I don't think I've seen anything with that much foliage removed survive.

I try to remove no more than about 30%

 

[Dav4]

Healthy junipers can have foliage drastically reduced during an initial styling but they will slow down for a year or two after. I wouldn't blink at 50% or a bit more foliage removal if the design warranted it but 70-80 % will almost definitely severely affect the short term health and vigor of the tree and be potential dangerous even with on point aftercare. Planned reductions over several stylings with meaningful recovery and redistribution of energy in between work would be a better option.

 

[Hartinez]

With a nicer tree and one you prize, I’d take the slow approach for sure. With that said though, I have an entire thread dedicated to removing massive amounts of foliage on nursery stock junipers with great success. Recovery was slower than id like to see, but recovery took place none the less.

 

[Wires_Guy_wires]

I think it completely depends on how much foliage the remaining 30% is compared to the size of the tree.
I've hacked junipers back by 90% of their size (bad idea) and left about 5% of the original foliage, but they pulled through.

If a plant is super bushy, it's very easy to hack back to a small percentage of foliage, as it's relative %, and it'll stay healthy as long as the roots are functional. If there are just three branches with five tufts of foliage on a foot wide trunk, reducing more than 5% will kill it.

 

[bwaynef]

Here's a japanese article translated to english and published by Bill V. That's a pretty good indication of what is necessary ...as well as what's safe. Tip growth, particularly on runners, will drive recovery. (This from an article on developing an overgrown tree and building new branches. Similar work was already conducted in the article for a previous iteration.)

 

[Scriv]

I'm working on a decent sized shimpaku juniper and have been watching YouTube videos on styling. I've seen people cut off what appears to be 70-80% of the branches and foliage in the styling process. I've always read that junipers really depend on their foliage. What gives? I'm curious on your experiences and research on survival rates on such aggressively pruned junipers.

I’ve taken close to 80% without issue. Really depends on…

— how vigorous the tree is…
— time of year the work is performed — making sure the tree is an energy positive state (right now, prior to the push of spring growth would be a good time).
— size of the root mass compared to the quantity of remaining foliage…
—quality of substrate (an 80% reduction in a 5 gal nursery container w poorly draining field soil is a great way to drown a tree. Been there, done that.)

In most cases, if you dial in the right balance of water and oxygen and nutrition after a heavy reduction you’ll be fine.