How much can you reduce the root zone of a San Jose Juniper

[b]recently picked up some nice San Jose Junipers in 3 gallon nursery buckets in nursery potting soil. They all have thick nicely tapering trunks. Should make nice shohin sized trees, which is why I bought them. I suspect the buckets are densely filled with fibrous root systems at least that's how they appear on the surface and that's been my experience with nursery potted plants.

When I collect I typically remove all the field soil and reduce the root zone and that seems to work well, but when I attempt to do the same thing with nursery grown plants in this condition, I haven't has as much success. So, just wondering what other folks do in similar circumstances particularly folks who have experience with nursery junipers.

Any suggestions are appreciated.

Nursery tree are generally in much deeper pots than bonsai. Even with good roots, I never remove more than about 1/3, and then just plant in a smaller pot so they won't get that deep again. Takes a few years to get them into bonsai pots this way, but I've had good luck.

I've recently watched several Ryan Neil videos, and he says the strength of junipers is the foliage so maybe I'm being too conservative and you could cut roots back harder with an actively growing juniper.

I'm sure a lot depends on your climate and what kind of aftercare you can provide as well. Being in Phoenix I tend to leave more roots rather than less.

so in my opinion, this is a questions with a lot of "it depends"...the "rules" say to not bare-root junipers or remove more than 1/3 of the roots at a time...ive done both, at the same time, and they where fine...i think it mostly depends on the health of the tree, and how much energy it was able to store up the previous year...i also think after-care is more important than anything else with junipers when it comes to repotting after some drastic root work...example: you do some major root work, move it into a nice shady protected area, a few weeks later all is well in the world and you think to urself "well, lets move it into the sun let it grow"...a week later you have a junipre that is looking pretty dry and seems to be fading quick...then it dies...then you come back to the forums and say "but that mike guy said you could do some drastic root work and everything would be ok"...

the reality is this...junipers are able to maintain foliage for qquite some time with pre-existing sap (one of the reasons they are easy to root)...but that doesnt mean the roots hae recovered...so it may look good in that shady area, but then to throw it into full sun all of the sudden is a major shock to the tree and if the roots havnt recovered enough to uptake enough moisture...you end up with a crispy juniper. my advice would be that if you are going to do major root work on a juniper, then move it into the sun gradually...shade, dappled sun, then morning sun prtected from after-noon sun, then finally full sun...this can take several months depending on the tree and how it is recovering...misting the foliage and all that helps as well...

as far as the nursery pot thing goes, i have a theory about that, but its only a theory...so, in the nursery business, its all about making money, so time is important, and when moving stock to larger pots its not like the do root-pruning and comb out the roots nicely...they basically just romove the stock from the pot (which by now is a coiled mess of roots) and stick it in a pot the next size up...then new roots grow and those also become a coiled tangled mess, and the process repeats itself until it is sold...so by the time we purchase it, the root mass is usually nothing but a tangled coiled mess...well, in our attempt to get the roots untangled, we end up damging a good majority of the roots...like i said, just a theory

Michael T wrote:[b]recently picked up some nice San Jose Junipers in 3 gallon nursery buckets in nursery potting soil. They all have thick nicely tapering trunks. Should make nice shohin sized trees, which is why I bought them. I suspect the buckets are densely filled with fibrous root systems at least that's how they appear on the surface and that's been my experience with nursery potted plants.

When I collect I typically remove all the field soil and reduce the root zone and that seems to work well, but when I attempt to do the same thing with nursery grown plants in this condition, I haven't has as much success. So, just wondering what other folks do in similar circumstances particularly folks who have experience with nursery junipers.

Any suggestions are appreciated.

Short of doing experiments with a few trees you don't mind losing personal experience seems to be your best guide. When questions like this are asked there tends to be a number of answers that are surely perfectly valid for whomever offers it. Take your experiences, variables, skill, advice and desire and then do what seems right to you.

Sometimes they just die out of spite anyway.

Just Mike wrote:
as far as the nursery pot thing goes, i have a theory about that, but its only a theory...so, in the nursery business, its all about making money, so time is important, and when moving stock to larger pots its not like the do root-pruning and comb out the roots nicely...they basically just romove the stock from the pot (which by now is a coiled mess of roots) and stick it in a pot the next size up...then new roots grow and those also become a coiled tangled mess, and the process repeats itself until it is sold...so by the time we purchase it, the root mass is usually nothing but a tangled coiled mess...well, in our attempt to get the roots untangled, we end up damging a good majority of the roots...like i said, just a theory

Yeah, I agree. That is pretty much what happend. You are probably better off cutting the bottom 1/3 or even 2/3 of the rootball with an old knife, saw or something. Then clean out the leftover roots very carefyllu, or next year.

I remove 90 or even 95 percent of roots from junipers in large nursery containers. First I saw off about 2/3 of the bottom of the root ball, then I wash as much soil off as possible using strong pressure, and then prune the roots back to the point that just a few fine roots are remaining. I then pot into a training pot,or a over sized bonsai pot and then care for the tree as though it was a cutting ( misting, sun/wind protection etc) and within weeks the tree is ready to continue growing normally. Its' really all about details. Never let the roots dry out during the process, do in a shady place on an overcast day out of the wind , ensure the soil is watered right away and the top is kept moist and misted for several weeks.

I'm in the coservative camp and absolutely, positively agree with Mr. Lackhand. Remove 1/3 and loosen/comb the rootball being gentle with the fine feeders. You can train the rootball step by step during future repottings.

Next step is to sitback and enjoy your healthy junipers!

Best,

Augustine
central MD 7a

For nursery junipers whose roots fill a nursery pot, I simply take a saw and cut the bottom 2/3 of the rootball, scratch out the edges of the remaining rootball, then cut the SAME pot down by 2/3 and put the tree back in, and let it grow. I work on the top over the following year, and repot the next year.

Here is a link to a few recent photos of root pruning and potting shimpaku from 3 gallon to bonsai grow pots.

https://www.facebook.com/photo.php?fbid=10200745921950173&set=a.10200734478944105.1073741825.1225947337&type=1&theater

Nice work Jim. Thanks for the progression.

Geraldrain wrote:Here is a link to a few recent photos of root pruning and potting shimpaku from 3 gallon to bonsai grow pots.

https://www.facebook.com/photo.php?fbid=10200745921950173&set=a.10200734478944105.1073741825.1225947337&type=1&theater

Facebook says this is unavailable.

R U on facebook ? I wonder if only users have access ? that shouldn't be ?. Anyway, I'll provide a different link soon. ThnxG.

Geraldrain wrote:R U on facebook ? I wonder if only users have access ? that shouldn't be ?. Anyway, I'll provide a different link soon. ThnxG.

Yes I logged into my facebook account and got the same problem. Thanks for the alternate link.

I would never so hastily cut off the bottom third with a saw. My experience with nursery stock is they are planted pretty deep so they don't blow about. I would rake down to the surface roots then decide to take the bottom third away. I have recently done this with a hollywood juniper and the surface roots did not appear untill well below half of the size of the container it was in. So had I hastily cut the bottom third off I would of been left with a 6th of the rootball. So find your nebari first....then act on reduction. But as already stated I have reduced by more than a third of the rootball AND washed the old soild out completely in one sitting to no ill effect.