Cuttings propagation inorganic soil particle size

[Unagi]

I am planning to propagate a Chinese pepper (Zanthoxylum piperitum) and a Chinese elm (Ulmus parvifolia) via 10-20 cm cuttings (see pictures). I have an inorganic soil that I think is good for bonsai (I don't know the exact mix, it is called Luwasa Longtime). In theory, the particle size is 2-8 mm, but I took a picture of the particles for reference.

My questions:

1. Can I propagate 10-20 cm Chinese pepper and Chinese elm cuttings in a soil like that?
2. Does the size of the box matter? I plan to put them to 10x10x8 cm boxes (1 per box).
3. Do I need to wash the inorganic soil before propagation to not have rock sand in it? I don't know if it can attached to the root and block oxigen utake or something.
4. If you think the particle size is too big, should I sieve it to separate smaller particles?

Thank you!

 

[Kievnstavick]

In my limited experience with doing cuttings, the particle size is way too large for doing cuttings. I have gotten cutting to root in potting spoil, pure sphagnum moss, and 1-2mm sifted substrate. The small substrate contained either Pumice and pine bark, Vermiculite and perlite, or vermiculite and pumice.

The key aspect here is to make sure the cutting has enough surrounding moisture at all times to encourage root growth once the hormones and chemicals build up enough to develop roots. The cutting can also potentially take up a minuscule amount of water if needed.

Once the cutting occurs, you are essentially in a race against time between the cutting healing and putting out roots before the cutting dedicates from lack of water.

The size of the container it is put in essentially doesn't matter at this point until roots have developed. If you want to keep them in the same container as to not disturb the roots, this size is good enough for the first period of time for the cutting to establish. I putting my cuttings enmass into seed trays and leave them there until rooted or dead.

Mike from Katsune Bonsai recommends just using pure perlite with his tropical cuttings but that is a different beast that you can gather some information on.

According to Dirr and Heuser in their book The Referance Manual of Woody Plant Propagation, Cuttings of Chinese Elm (U. parvifolia) can be propagated from spring and summer cuttings.

(25.4mm per inch is the conversion)

6 to 12 inch long cuttings are reduced to 3 to 6 inches and the bottom 2 to 3 leaves are removed leaving a minimum of 5 leaves on top.

The cuttings are treated with rooting hormones, placed in vermiculite and perlite at a 1 to 1 ratio, and kept under mist or high humidity.

They don't have information on the Cinese pepper. So outside of the internet information, you'll probably have to expirement.

 

[Deep Sea Diver]

Haven’t tried this media.

We generally use smaller particle size, using peat : perlite 70:30 for mainline species or perlite : coco coir 70:30 for drier species like juniper. .

The only inorganic media we’ve used is kanuma 2-3 mm with a layer of chopped sphagnum underneath.

Cheers
DSD sends

 

[pandacular]

I have a few friends who have good success with chunky (~6mm) pumice for juniper cuttings, so its doable. I would personally probably use something cheaper than the mix you’re using, such as the ones DSD recommends.

 

[Unagi]

Thanks, I do have a few liter of Perlite still (2-6 mm particle size) and about 25L universal bio soil bought in a garden center close to me. They say "Type and origin of starting materials: Mixture of bark compost, cocopeat and vegetative structural fibre with organic fertilizer. pH value: 6.5 - 7.5 (CaCl2)". I have used this soil before but it feels so soft, when I added water to it, it was almost like a soup.

What I read from your replies is that this universal bio soil with perlite (soil 70% / perliete 30%) is what I should use, right? In case I have at least 4-4 cuttings per tree, I might experiment planting 2-2 per tree to the bio soil and to the inorganic soil.

6 to 12 inch long cuttings are reduced to 3 to 6 inches and the bottom 2 to 3 leaves are removed leaving a minimum of 5 leaves on top.

I read that in the book, but unfortunately, I don't have such a long brances, while I still would like to experiment with propagation this year. I hope that 3-6 inch long cuttings will also lead to some success.

I have only these two threes, and I would like to learn on them as much as I can. I am planning to create a post for each tree to explain what I am planning to do on them, but I don't have the content ready yet.

 

[eugenev2]

Thanks, I do have a few liter of Perlite still (2-6 mm particle size) and about 25L universal bio soil bought in a garden center close to me. They say "Type and origin of starting materials: Mixture of bark compost, cocopeat and vegetative structural fibre with organic fertilizer. pH value: 6.5 - 7.5 (CaCl2)". I have used this soil before but it feels so soft, when I added water to it, it was almost like a soup.

What I read from your replies is that this universal bio soil with perlite (soil 70% / perliete 30%) is what I should use, right? In case I have at least 4-4 cuttings per tree, I might experiment planting 2-2 per tree to the bio soil and to the inorganic soil.


I read that in the book, but unfortunately, I don't have such a long brances, while I still would like to experiment with propagation this year. I hope that 3-6 inch long cuttings will also lead to some success.

I have only these two threes, and I would like to learn on them as much as I can. I am planning to create a post for each tree to explain what I am planning to do on them, but I don't have the content ready yet.

You'll find that many things bonsai related is very climate depended. People in the tropics just shove sticks into the ground and they have success. You will need to have a look at what people close to your climate advise, one of the tricks i've learned from the form is, as advice from one persons climate might not work for you.

But general advice is you want the cuttings not to dry out, but not stay too wet, so humidity is key here. So in my climate those junky inorganic soil is a big no no for cuttings, i'll struggle to keep them moist, but we don't get a lot of rain and have naturally low humidity levels, this might not be the case for you.
The other thing to watch out for is possibly pathogens or other unwanted things that could come with those mixes, so you're probably better of using something sterile like peatmoss/coco coir with your perlite, but i would most likely flip that ratio 30% organic and 70% perlite, with this then you add some sort of humidity chamber/container that lets light through but keeps humidity high
The other key aspect is sun light, also climate/elevation depended, but for the most part a bright place with no direct sunlight should do