Quick question about rooting cuttings

[777thSunRay]

I’m just wondering, what is the smallest/thinnest, branch twig or stem, which can be made to grow roots with a root starter? And does the answer also vary depending on carefulness of methods, like sterility, perfect temp and light, and other conditions, etc.

 

[just.wing.it]

I think root cuttings refer to roots, not branches, twigs or stems.
For example, when you do an initial repotting on an Elm tree, you'll be removing some large undesirable roots, which can be planted on their own to propagate a new tree, often with interesting trunk movement because it was a root, not a branch.

 

[jeremy_norbury]

It's a combination of things which determine success with cuttings: species (plus cultivar plus age), a question of timing, rooting environment (largely humidity and heat) and plain old good luck.

The goldilocks rule applies: tiny cuttings are generally difficult as are very thick ones but the ones in the middle work best.

 

[Wires_Guy_wires]

I once grew a citrus plant from callus tissue. It grew roots at about 1mm in height. But my actual limit is a pollen grain. 50 micrometer or something like that.

Pencil seems to be the best size, in general.
Smaller will root easier, but will take longer to grow to pencil size. Bigger will root slower and more difficult, but they have a substantial size already.

And some plants, just make it hard for everyone. Like pines and in my case junipers. I've rooted more pine cuttings than juniper cuttings even though I took about a similar amount of cuttings from both.

 

[Crazy Diamond]

I once grew a citrus plant from callus tissue. It grew roots at about 1mm in height. But my actual limit is a pollen grain. 50 micrometer or something like that.

Pencil seems to be the best size, in general.
Smaller will root easier, but will take longer to grow to pencil size. Bigger will root slower and more difficult, but they have a substantial size already.

And some plants, just make it hard for everyone. Like pines and in my case junipers. I've rooted more pine cuttings than juniper cuttings even though I took about a similar amount of cuttings from both.

Wow thats weird xD what pines you rooted?

 

[Wires_Guy_wires]

Mugo, JRP, JBP, and ponderosa. Some scots pines in my early days when I didn't do bonsai.
JRP, JBP and mugo as adult cuttings, ponderosa, JRP, JBP and scots pines as seedlings.
Seedlings were easy. Adult stuff has a success rate of around 20%, and a low survival rate.

 

[River's Edge]

I’m just wondering, what is the smallest/thinnest, branch twig or stem, which can be made to grow roots with a root starter? And does the answer also vary depending on carefulness of methods, like sterility, perfect temp and light, and other conditions, etc.

The Reference manual of Woody Plant propagation is a great resource if you want to do the deep dive and gain a firm understanding of the process and variety of techniques available for special circumstances. Dirr and Heuser several printings available and generally considered an excellent reference.
It answers your question in the space of roughly 400 pages. Soft cover 81/2 by 11 inch text.
recommend the second edition.

 

[777thSunRay]

I think root cuttings refer to roots, not branches, twigs or stems.
For example, when you do an initial repotting on an Elm tree, you'll be removing some large undesirable roots, which can be planted on their own to propagate a new tree, often with interesting trunk movement because it was a root, not a branch.

Appreciate the clarification! What would be the correct descriptor?

 

[just.wing.it]

Appreciate the clarification! What would be the correct descriptor?

You got it, "root cuttings".... at least that's what I've heard.
I've also trashed hundreds of cut roots that I could've used as root cuttings.....only because I have limited space on the benches.

 

[Soup Dragon]

Appreciate the clarification! What would be the correct descriptor?

Just "cuttings". I think your question was phrased correctly. You were asking about how to to ensure that cuttings root (verb - to produce roots) rather than about root (adjective) cuttings (cuttings from the roots of the plant rather than from a branch or stem).

I'm not sure how we got onto the topic of root cuttings.

 

[just.wing.it]

Root cuttings already have roots.

 

[Crazy Diamond]

If you make a branch cutting from a root cutting that already have roots its cutting from a rooted root cutting?

 

[just.wing.it]

If you make a branch cutting from a root cutting that already have roots its cutting from a rooted root cutting?

Exactly! Hahaha.

Actually, again, "rooted root cutting" is redundant.
Root cuttings already have roots.

We talk about rooting cuttings (of branches) because they have no roots.....but they may have leaves.

So maybe, the best thing to say is that one roots a branch cutting and leafs a root cutting!