What will generate ROOTS in junipers?

I repotted two healthy junipers this year for esthetic reasons.
To put in a nicer pot.
BOTH of them had almost NO white roots. And certainly no BIG white ones.
Both were healthy but I can't see how with such meager rooting.
I think both are procumbens, one twisty and large (2-3') and the other rough barky and tall. (16-18") Both nicely greened up. The larger one is smoother bark but not sure of needles.

The roots though. (My phone camera is out of service for replacement) The few TINY white roots weren't in profusion, but ...scattered.... in my opinion quite sparsely and barely peeking out of the root ball. I didn't mess into them heavily because they looked so fragile.

So.... question.

Got any idea what a meager rooting juniper would like to have?
0-10-10 fertilizer (or different but without the N)
Drier conditions?
Wetter conditions?

The soil is lava, akadama, pumice and some locally sourced highly recommended "planting soil" that the bonsai group swears by. Not a "brand" but "mixed" at the soil place.

Any suggestions welcome.

(oh yeah...edit....)
After seeing the roots, instead of "nicer" pots, I put em in the plastic ones with the bottoms "all holes" which have rejuvenated many of my "ailing" trees very nicely.
So...there is PLENTY of drainage.

Mike Corazzi said:

I repotted two healthy junipers this year for esthetic reasons.
To put in a nicer pot.
BOTH of them had almost NO white roots. And certainly no BIG white ones.
Both were healthy but I can't see how with such meager rooting.
I think both are procumbens, one twisty and large (2-3') and the other rough barky and tall. (16-18") Both nicely greened up. The larger one is smoother bark but not sure of needles.

The roots though. (My phone camera is out of service for replacement) The few TINY white roots weren't in profusion, but ...scattered.... in my opinion quite sparsely and barely peeking out of the root ball. I didn't mess into them heavily because they looked so fragile.

So.... question.

Got any idea what a meager rooting juniper would like to have?
0-10-10 fertilizer (or different but without the N)
Drier conditions?
Wetter conditions?

The soil is lava, akadama, pumice and some locally sourced highly recommended "planting soil" that the bonsai group swears by. Not a "brand" but "mixed" at the soil place.

Any suggestions welcome.

(oh yeah...edit....)
After seeing the roots, instead of "nicer" pots, I put em in the plastic ones with the bottoms "all holes" which have rejuvenated many of my "ailing" trees very nicely.
So...there is PLENTY of drainage.

Click to expand...

Junipers don’t have fat white roots, but a healthy one should have a lot of fine roots. A juniper is heavily dependent on its foliage for carbohydrates, so don’t withhold nitrogen.

If they're in good health, there's enough roots for them.
I'm growing a tiny rootless Juniperus Chinensis cutting. It's doing better than the one with a few roots.. I'm starting to become more and more convinced that junipers don't abide to normal plant laws.

Lowering humidity, increasing photosynthesis, stop feeding carbohydrates, and omitting P and N from the nutrients should increase rooting in most plants. But more than once have I seen all of the above have zero effect.

If your trees are in recovery (which the edit implies), they might just be investing in foliage first. Time is an important factor not to be overlooked, of course.

Pics from a yesterday repot. Ricky mountain juniper
If that looks good enough for you (looks good to me) this gets lots of water but in a well daring mix. Fertilized with organic pellets on top. A mix of fish and kelp liquid every couple weeks. Don’t forget the kelp I believe the mix is better than fish alone.

PiñonJ said:

Junipers don’t have fat white roots, but a healthy one should have a lot of fine roots. A juniper is heavily dependent on its foliage for carbohydrates, so don’t withhold nitrogen.

Click to expand...

Root size seems to depend a lot on soil actually. I have recovering rmj in half inch pumice with huge big fat roots. In the mountain soil they’re so small and thin you can easily believe they are not even there but with a close enough look can see millions. In my mix as the pic above I imagine with akadama or more organic there would be more fine roots than my pics.

My evidence shows that size matters. I have been repotting my junies and those that have been in turface all have very fine roots and the ones that have been in 1/4"- pumice have larger less hairy roots. The white roots are just the ones that have lignified. How many there are depending on how early or how late you are repotting.

Coarse soil will generate coarse roots. Small soil particles will generate smaller, thinner roots.

So, newly collected trees, or trees with damaged roots do well in a medium of coarse soil. Often, we use straight pumice. This promotes fast root growth. Fast root growth = coarse roots. The fat white ones.

Once a tree has become established and stable, a nice root ball is developed, we don’t need rapid coarse root development anymore. That’s when we prefer to have a rootball that consists of the small hair roots, as known as “feeder roots”. These will be highly ratified, and in junipers they are “fibrous”. Being full of small roots, they are very efficient at absorbing nutrients.

So, one of the reasons we use Akadama, lava, and pumice for bonsai, us when we first repot, we want rather rapid root growth to populate the new soil. The new fresh soil course, so at first, the new roots going out into it will be the large, course, new roots. But later, the akadama starts breaking down. This encourages a finer root system to evolve.

So, now Mike, let’s get back to the question you asked, “How do you get thick white new roots?” The answer would be to use something like 100% pumice as your substrate.

The question I have is, Why? Why do you want those kinds of roots? Is it freshly collected material with weak roots? If so, then 100% pumice is a good idea. Is it because you’ve seen pictures of someone posting a picture of their tree on the Internet with the caption “Look at these big white roots!”, and you think it’s a good thing? Well, it may, or may not be a good thing! Rapid course root growth will stimulate rapid, course foliage growth. Which might not be what we want if we have a highly refined tree!

wireme said:

Ricky mountain

Click to expand...

Ever seen a Ricky Martin Juniper?
They have lots of movement and grow like weeds all over Puerto Rico and LA... I've also heard that they respond positively to Latin Pop music!

just.wing.it said:

Ever seen a Ricky Martin Juniper?
They have lots of movement and grow like weeds all over Puerto Rico and LA... I've also heard that they respond positively to Latin Pop music!

Click to expand...

Mine are more like trailer park boys Rickys.

“Learning by denial and error”

“Don’t worry about it it’s just a little f””ing worse than it looks that’s all”.

The worst case Ontario!!

My favourite, “getting two birds stoned at once”

wireme said:

Mine are more like trailer park boys Rickys.

“Learning by denial and error”

“Don’t worry about it it’s just a little f””ing worse than it looks that’s all”.

The worst case Ontario!!

My favourite, “getting two birds stoned at once”

Click to expand...

Hahaha!

Just finished poking another. Took pics since we’re talking juniper roots.

First repot since collection was in 1/4”ish pumicy mix. 1/8 for the upper half inch of soil with a half ass moss layer over top.
Grew some fattie roots along the bottom for sure. Finer ones up top.
Moved up a size in pot, down a size in soil and used more organic this time around.
I don’t know if this helps Mike, I just really like root and repot pics!
As usual Adair’s given more complete info. I have to wonder how long yours were in the previous pots because I’d expect larger obvious roots circling the bottom regardless of potting media. From the sounds of yours though., with akadama and potting soil type stuff., there may have been a lot more nice root than you thought, just very fine??
Anyhow, later, more trees await.