advice on juniper needed

[peterb]

Hi all
another question but if you don't ask you don't learn. I have a chinese juniper procumbens, which i have grown for +- 5 years, i wired the branches as per the books but didn't grow the pads out properly i just tip pinched not really knowing what i was doing ,but then my bonsais took a bit of a backseat to my daughter when she was born, i pinched the tips a few times but the tree ended up looking like candle flame, i'v wired out the branches flat again and will try again , i've just rejoined the sa bonsai society again after a 4 year absence so hope to get some advice from them on pads , long windedly i have arrived at my question, when i planted the tree i left as much of the original soil as i could ( i was scared of killing it ), it has been repotted twice but still has a lot of old soil, is it safe to bare root a juniper or do you keep the old soil around the central rootball , i tried to expose some surface roots but the soil is very mossy muddy, when is the best time of year to remove soil so that i know for next year when i repot , also what is a good soil mix for juniper. any advice welcome
regards
peterb

[63pmp]

Hi Peterb,

I only have two of these plants, and I'm not sure how they ended up in my garden. I repot just as they seem to be starting to shoot. Use well draining potting mix, ie large particles of mostly inorganic material. I bare rooted mine early in life, and then stuck them in big pots to grow out. Though there are due for repotting again, so I'll repot them next year. They seem to grow lots but never really thicken their trunks. If your concerned about taking off too much soil, do half of the root ball one year, and the other half next year. I'm not sure how much root you can safely remove, probably not a lot, so be conservative.

I've just repotted an air layer I took off a long sacifice branch, seemed a waste to just cut it off and throw it away, It recovered well in the shade house after potting, tie it into the pot so it doesn't move, and I held back on fertiliser until showing signs of growing.

Maybe somene else will come by with more experience and chip in, or correct (if needed).

Paul

[peterb]

thanks paul will try what you suggested
regards
peterb

[Andrew E]

Hi Peterb,
Good to see you getting back into it. Always challenging to keep up the work on the trees when the young ones start arriving on the scene.
As Paul said, junipers prefer a fast draining coarse mix. Being a conifer they prefer to have some of the soil remain due to the symbiotic relationship the tree has with the mycorrhizae in the soil. Deciduous trees have it their roots whereas its in the soil with conifers. Having the old soil means the mycorrhiza can re-colonise the new soil quickly which aids in the recovery of the tree. Removing all the soil, means the tree will probably sulk until the soil can be recolonised. The tree won't necessarily die just take longer to come back. Aftercare of a tree is the most important factor of repotting.
When the old soil is sludgy or too heavy then it must be removed for the health of the tree will suffer if it isn't. After repotting, mist the needles and put it in a semi-sheltered position. Once new growth is evident (about 6 weeks), feed regularly. Use seasol during the recovery period every 2 weeks.
Good luck with it
Andrew

[63pmp]

Regarding the myccorhiza,

Vance Wood recommends when bare rooting mugo to rake out the old soil gently, but not to wash the roots. According to Vance, this prevents the myccoriza from being lost and speeds up recovery. I imagine it would be the same with Junipers.

Something to think about anyway.

Paul

[bodhidharma]

All great advice. The only thing i can help with is to not be hasty in trimming Juniper roots. Rule of thumb when reducing root ball size is to leave a third of it and reduce over a period of time instead of one hit.

[peterb]

thanks for the advice everyone, in order to reduce soil do i work my way to the centre bit by bit when repotting or do i do a 1/4 at a time what would you's suggest, i also read someones soil mix on the forum as 80% diatomite, 10% zeolite and 10% peatysand does this sound ok
regards
peterb

[63pmp]

Hi Peter,

I'm not familiar with diatomie or peatysand so can't advise on that. It's the particle size that is most important, 2-5 mm, with not too many 2mm sized ones. Its hard to explain in words, but the porosity of the mix will be more open if the bulk of the particles are in the range 3-5mm. The smaller particles tend to sit in the pores made by the larger particles, so not too many small particles. Of course, more porosity the more you have to water, its a trade off.

When removing 1/4 of the old soil, work right into the root ball to the base of the trunk, completely replacing all of the soil in that section. Its a tedious job, but important, its easier to do 1/2, but it depends on how badly the tree needs new soil and the trees strength. Its the old soil nearer to the trunk that is the main problem as often this is slow to dry out, leading to low oxygen levels in these regions, and fungal infection, so its very important to remove this soil. Just cleaning out around the edges will eventually cause two problems, long rooted nebari,and deterioration/clogging of the soil under the root ball, so its either too wet or too dry, neither healthy.

Paul

[peterb]

hi paul
thanks for the advice very helpful , is it to late now for this year
regards
peterb

[63pmp]

Sorry to take so long to get back to you,.

When to repot is determined by the gorwth of the tree. You have to watch and when it seems that the buds are about to appear is when to repot. As far as I can tell. Maybe some one else knows a better time.

I can't say, sitting here in the central tablelands of NSW, if its a good time to repot a juniper in Adelaide. I couldn't tell you if you lived in Sydney. I've notice that there is a 2-3 weeks lag from trees in my back yard, and trees in the paddock 400 metres away, And these are different to what plants are doiing ten kilometers away. Every climate is different, look at your trees for guidance.

Paul

[peterb]

thanks paul, my tree is growing out for a few weeks now but a person with years of experience in the adelaide area looked at my tree today and was very critical of my soil and said i was going to lose my tree soon because of water logging, so he said i had to go ahead and repot now, he was kind enough to give me some maidenwell diatamite to plant my tree in and said i must come around to his place and he would watch what i did
kind regards
peterb

[JulzD]

Peter,

How goes the Juni? Did you repot? Did you lose it?