Repotting a big juniper

[Tim.E]

Hey everyone,

I've got a question regarding the repotting of a big mint Julip juniper I plan on doing in spring. It is a well established nursery Juniper growing in some really poor clay/sand soil. I'm newer to juniper repotting and I'm unsure as to how hard I can go on it when it starts extending growth in spring. Can you bareroot em and prune aggressively seeing as they are foliage dependent? Any feedback would be great and I'll throw a picture up of the juniper later when I get home from work.

Thanks

Tim

 

[DougB]

The answers will greatly depend on your location Tim. Please modify you profile to include your location. Many here are will experienced with junipers. They will need to know how big your mint julep juniper actually is, if you are going to work on the top and the size of the pot. Pictures will help as well.

Welcome and good luck.

 

[sorce]

I could use a good juniper from nursery soil repotting rundown myself.

Sorce

 

[Tim.E]

Hi Doug,

Thank you for your quick response! I have updated my profile, I am in Barrie, ON Canada and my USDA zone is 5a. I do not plan on styling this tree for another year after the repotting to allow it to establish itself sufficiently. Not sure what size the pot is but i'm guessing probably a 7-10 gallon nursery pot would seem right. I have a thread on this tree at http://www.bonsainut.com/index.php?threads/twin-trunk-mint-julep-juniper.20700/ already created if you want to check it out over there. I have included some previously taken pictures of the tree. I think it has some pretty awesome potential and it is definitely very vigorous from what I've seen so far.

Any insight would be amazing from you guys!

 

[Tim.E]

I could use a good juniper from nursery soil repotting rundown myself.

Sorce

Yeah I've found it hard to get good info on this exactly. Some people have said to go ahead and bareroot, others have indicated not to as they can be like pines where you do not want to get rid of too much of the original soil. Very conflicting info on how you can get to grips with repotting new material.

 

[GrimLore]

Any insight would be amazing from you guys!

The method of just bare rooting 1/2 the first time and 1/2 the following year is often done on larger stock. Myself I avoid repotting Junipers and have left them in the same container and substrate for several years. When I do repot them I will most often saw off a fair amount of the bottom root and brush/rake out the outer edges of the root mass. I never bare root Junipers, Azalea and a few other plants.

Grimmy

 

[Tim.E]

The method of just bare rooting 1/2 the first time and 1/2 the following year is often done on larger stock. Myself I avoid repotting Junipers and have left them in the same container and substrate for several years. When I do repot them I will most often saw off a fair amount of the bottom root and brush/rake out the outer edges of the root mass. I never bare root Junipers, Azalea and a few other plants.

Grimmy

Thanks for the info Grimmy! My only concern is still the original soil which the juniper is growing in. It's VERY hard to get good water penetration but once it is wet, it stays super wet for a long period. It makes me concerned about the possibility of root rot. Would you still only bare root half and back fill with almost all inorganic to improve the drainage some?

 

[GrimLore]

Thanks for the info Grimmy! My only concern is still the original soil which the juniper is growing in. It's VERY hard to get good water penetration but once it is wet, it stays super wet for a long period. It makes me concerned about the possibility of root rot. Would you still only bare root half and back fill with almost all inorganic to improve the drainage some?

Yes - It will stress it far less. I understand your "concern" about the current substrate BUT that Juniper looks pretty darn happy! Many here, myself included leave Junipers in the original muck they came in for several years while torturing them as they often respond poorly to any repot until they are WELL established.

Grimmy

 

[fore]

Tim, for container junipers where there's a lot of roots, and it's young like yours. You can remove some roots from the bottom and sides to fit container. But for yamadori, you don't root prune at all. You layer them back into pot. Only, yrs later, when it's packed full of roots do you start cutting these back. Pick the best container and substrate as you don't repot but every 5yrs or so.

 

[Tim.E]

Yes - It will stress it far less. I understand your "concern" about the current substrate BUT that Juniper looks pretty darn happy! Many here, myself included leave Junipers in the original muck they came in for several years while torturing them as they often respond poorly to any repot until they are WELL established.

Grimmy

Awesome thank you for the feedback! In your opinion would you have a go at the tree now? The tree is definitely vigorous and full of compact old growth. If so, any suggestions on styling the tree? I've debated doing a twin trunk or making a single trunk with lots of deadwood.

 

[Tim.E]

Tim, for container junipers where there's a lot of roots, and it's young like yours. You can remove some roots from the bottom and sides to fit container. But for yamadori, you don't root prune at all. You layer them back into pot. Only, yrs later, when it's packed full of roots do you start cutting these back. Pick the best container and substrate as you don't repot but every 5yrs or so.

Awesome fore thanks for your help. I have to admit, attempting to collect junipers seems daunting at this point, i had a go at one in my parents garden as they were re-landscaping but the main tap root went for what seemed like 8 feet under the patio stones and lawn. Wasn't able to get enough fine roots to keep it alive unfortunately

 

[GrimLore]

Wasn't able to get enough fine roots to keep it alive unfortunately

The tap root normally is not needed as we anchor the plants in with wire - the tap root is nature doing it itself for the most part. The more fine root the better but I suspect many are lost because they dry to much. If you want to kill most any Juniper or set it back a year or two let it dry out in the pot one time - pretty certain yours is happy "damp" so you have a better idea why. The balance with damp is very difficult with total non organic unless you can water a LOT and why many leave them in decent draining crap like a mix of premium topsoil, coarse sand and perlite... It just works and does fine until very root bound - takes years and is easy to fix.

Grimmy

 

[Tim.E]

The tap root normally is not needed as we anchor the plants in with wire - the tap root is nature doing it itself for the most part. The more fine root the better but I suspect many are lost because they dry to much. If you want to kill most any Juniper or set it back a year or two let it dry out in the pot one time - pretty certain yours is happy "damp" so you have a better idea why. The balance with damp is very difficult with total non organic unless you can water a LOT and why many leave them in decent draining crap like a mix of premium topsoil, coarse sand and perlite... It just works and does fine until very root bound - takes years and is easy to fix.

Grimmy

I understand and I think you've convinced me to hold off on repotting this guy for now. At this point I don't really have a pot big enough for him regardless so that saves that expenditure as well! I'll have some time to style the tree this Friday, I can post some pictures when I'm working through that.

 

[GrimLore]

I understand and I think you've convinced me to hold off on repotting this guy for now. At this point I don't really have a pot big enough for him regardless so that saves that expenditure as well! I'll have some time to style the tree this Friday, I can post some pictures when I'm working through that.

Also it is really a good idea not to repot and work most at the same time so you will be doing what many do here with albeit long term but good success. Look forward to progress!

Grimmy

 

[Tim.E]

Also it is really a good idea not to repot and work most at the same time so you will be doing what many do here with albeit long term but good success. Look forward to progress!

Grimmy

Yeah the plan was always either repot or work the tree. I have worked some junipers WAY to hard in the past and am starting to learn all about what is realistic with material. What would be a good indication that a repot is needed? Will it show in the foliage first or is it more based on some acquired intuition?

 

[Tim.E]

Yeah the plan was always either repot or work the tree. I have worked some junipers WAY to hard in the past and am starting to learn all about what is realistic with material. What would be a good indication that a repot is needed? Will it show in the foliage first or is it more based on some acquired intuition?

The reason I ask is that I'm more than certain that I can kiss good buy to my eastern white pine due to the original organic soil being over watered and the tree showed signs too late before I could react.

 

[GrimLore]

What would be a good indication that a repot is needed? Will it show in the foliage first or is it more based on some acquired intuition?

While your developing and styling in the original substrate in a few years you will notice drainage issues. The most obvious is when the water runs away from the base of the tree and down to the sides running out of the container. That could be accompanied by roots growing out of the drain holes and/or the roots on the surface actually becoming the surface. I have noticed if it is just roots on the surface I simply cover them with substrate if the plant accepts and drains proper. Watch what happens when you water and in time you will know at the first sign of problems.

Grimmy

 

[Tim.E]

While your developing and styling in the original substrate in a few years you will notice drainage issues. The most obvious is when the water runs away from the base of the tree and down to the sides running out of the container. That could be accompanied by roots growing out of the drain holes and/or the roots on the surface actually becoming the surface. I have noticed if it is just roots on the surface I simply cover them with substrate if the plant accepts and drains proper. Watch what happens when you water and in time you will know at the first sign of problems.

Grimmy

You are a treasure trove of knowledge man. Last question related to overwintering the juniper after styling. I'm assuming baby it out of frosts and wind but how much light does a juniper require during the winter months? Would a garage with some minor natural light weaken the plant to much? Or can the tree be styled and left in a protected area of the yard for the winter?

 

[GrimLore]

You are a treasure trove of knowledge man. Last question related to overwintering the juniper after styling. I'm assuming baby it out of frosts and wind but how much light does a juniper require during the winter months? Would a garage with some minor natural light weaken the plant to much? Or can the tree be styled and left in a protected area of the yard for the winter?

You present some tricky questions Sir But I will tell you how I handle mine without killing them as best as I can. First and foremost I used to live near the Peace Bridge and I find they react the same way here. Second - I am talking about HEALTHY plants and from the pictures I am "pretty certain" yours is. Most Junipers will and should handle outdoor Wintering seeing 1 and 2 are met. Mine get minimal wind protection and normally get put on the ground with a small wedge to allow draining. Many stay under/in snow, turn, blue, purple, brown and wake up early Spring returning to nice foliage colors. Done that way I minimize watering as once they are frozen rarely thaw enough to require it. Sounds to simple but it works and I know for a FACT it works better then in a shed/garage/or similar. Now to styling - I am guessing you just want to clean it out a bit to see the structure of the plant better. You could do more then that IF you feel it is in great health.
I am going to PM you with my phone number as there are a few more considerations as well. Also I am available right now as I can prep dinner and chat...

Grimmy

 

[fore]

Good advice Grimmy. Also, it's best, if given a choice to style first and then pot up. This way, you can pot in the orientation and direction you want. Best time to style is in the spring...gives tree immediate resources to tolerate stress of styling. You typically do a 'summer cleanout' of crotch branching, underhanging branches and weak interior growth. You can work/expand deadwood anytime of the yr...but if you want to jin alive branches, it's def. easiest to do before spring growth hardens off.