AusBonsai

As I was pruning this year's batch of black pine seedlings several thoughts occurred to me:
1 - the best material for striking pine cuttings is juvenile growth. In commercial P. radiata production stock plants are cut back regularly so they produce juvenile growth that can be used for cuttings.
2 - The tops I had cut off the seedlings were the ultimate in juvenine pine growth.
3 - The recognised method for making black pine seedling cuttings (cut the stem at the purple and set the top as a cutting) might not be the full story. It does work but the result is still only 1 plant from each seedling and in the long run, the results are no better than well root pruned seedlings.

After tossing these thoughts around for a bit I decided to experiment and set 15 of the larger tips i had cut off the seedlings as cuttings.
4 weeks later and here's what happened: As you can see i got 14 rooted cuttings and 1 with callus but no roots yet.
Most of the cuttings have produced multiple roots around the base which is the desired outcome. to help improve the future nebari I cut back the new roots before potting up into 10 cm pots. as you can see this method is very successful and, as a bonus gives 2 plants for each seedling - the original seedling currently growing in its pot as well as a new cutting.
I still have a few seelings that I have not yet cut so I'll probably do a few more to see how time of year affects the results.

Is it my eyes or have the lower "trunks" of the cuttings swelled up more than they were before the cutting?

Great little twist on the proven methods, but this way you get 2 for 1. Great!

If you do the other seedlings you havent pricked out yet id be interested to see where you make the cut.

Thanks for documenting this Neil,

Joe.

Good eyes Jow. I forgot to mention the thickened stems of the rooted cuttings. Now about 3 times diameter of the stems I put in. it will be interesting to watch and see if that continues.

No special place to cut the seedlings. Because my aim was to force low buds on the stems I cut them about 1 cm above the lowest leaves but striking cuttings is about juvenile growth so I think cutting anywhere on the seedling stem should give viable cuttings. Some of the tips I had pruned off were too short to handle easily and were discarded. I used 2-4 cm long tips but will also try cutting some of the longest stems into 2 cuttings.

I'll make sure I take the camera when I do the next ones.

If the stem thickening continues as they grow you could be onto something!

Well that didnt take long.

I just put down a tray of cuttings this morning.

Thanks for the motivation and inspiration.

Squizz

How magical is that! I'm going to give that a go. Thanks for the info and inspiring me.

I'd like to see this experiment continued again and again as the pines grow so that we can learn how many times you can cut and root the re-growth before the percentage of successful rootings start falling.

With experiments on both the original root stock and also the cutting, and the cutting of cutting.

Are you planning on continuing your testing Shibui?

If this does work indefinitely, you may have single handed solved Australia's black pine seedling shortage with simple cloning techniques. Everyone wants black pine seed, no-one can find it.

That's very interesting work Shibui. I've not heard of anyone sticking juvenile, juvenile cuttings.

I've done seedling cuttings on maple (not had any pine seed to work on) and I think the idea that the technique provides better radial root development is rubbish. What seedling cutting does do is bring the first node close to the ground. If maple seeds are left to their own devices the first node is approx 6-8 cm above the roots. This is no good for mini bonsai. If the seedling is cut at the dicot or first true leaf emergence stage, then the first node can be a centimeter from the roots. Additionally, the next couple of nodes are shorter. This is the real benefit of seedling cuttings.

Regards

Paul

Thanks for all those great ideas. plenty to keep a few of us amused for years to come finding out what will work and how far we can take this. Might glut the Black pine market though
First step to take some more cuttings to see what happens at different times of year. Hopefully I will have one seedling that is tall enough to try 2 cuttings to see if non terminals work then maybe see if these initial cuttings will grow enough to yield some more cuttings to satisfy Webos' curiosity.

I've done seedling cuttings on maple (not had any pine seed to work on) and I think the idea that the technique provides better radial root development is rubbish. What seedling cutting does do is bring the first node close to the ground. If maple seeds are left to their own devices the first node is approx 6-8 cm above the roots. This is no good for mini bonsai. If the seedling is cut at the dicot or first true leaf emergence stage, then the first node can be a centimeter from the roots. Additionally, the next couple of nodes are shorter. This is the real benefit of seedling cuttings.

I agree and have been saying for some time that root development is no better. Your proposal that first nodes are lower is well worth thinking about some more Paul. Something else to cogitate and observe........

Very interesting info in here Neil. We're about to grow a bunch of JBP seedlings here in Cape Town, and this technique could be worth experimenting with. A few questions if you don't mind.

1.) Gotta ask it . . . . . . what's your mix made up of?
2.) Last year, did you tip prune to get new branches, or were you just pruning the top of the main stem to make these cuttings?

Cheers, and great thread!

Andrew

Andrew, these are cuttings from very young seedlings. The seedlings themselves were only about 10cm tall and I cut them in half to force low shoots. the cuttings are the top half of the seedling.
I have tried pruning older trees to get juvenile growth but have not been successful yet. Later pruning seems to produce some juvenile shoots so Late summer pruning may work better. The original impetus to try came from an article about commercial production of P. radiata here in Aust where the majority of the millions of trees planted each year are cutting grown from selected clones for growth rate and form. They prune the stock trees then use the resulting juvenile growth as cuttings - not sure of timing though. Someone may have time to search some answers?
Winter cuttings from JBP have yielded variable results - sometimes 60% success, other times 0%. Spring and summer cuttings of material from new growth has failed several times for me.

These are in my standard cutting mix - 50/50 coir peat/perlite. Last season I struck some winter JBP cuttings in straight perlite. All have been kept under intermitent mist but no bottom heat (only because I don't have it)

Some more pics of this seedling cutting process coming.

I have updated the Shibui Bonsai blog with more info and pics.
http://shibuibonsai.com.au/

Thanks mate!

Here are my cuttings. Still alive. No special treatment though its been a mild winter here.

I can be certain that at least two of these have roots. Thanks for the idea Neil.

Squizz

I did a quick post on my blog comparing the difference between seedlings cuttings and straight seedlings.
Seedling cutting
Straight seedling
Comparison between the two

The positives and negatives of each approach:

Seedling cuttings
+ Shorter 'gap' between the first set of needles and the roots, roughly 2cm vs 5cm.
+ More radial root growth, all emerging from one point on the trunk rather than from a tap root.

- Some cuttings did only produce one or two roots.
- Thiner, shorter, not as far advanced.

Straight seedlings
+ Size! They were significantly thicker and longer.
+ More roots, more advanced development (needles, number and length), overall healthier.

- longer 'gap' between the first set of needles and the roots roughly 5cm
- a tap root with feeder roots emerging along its length.

As a backyard grower, I would definitely use the seedling cutting technique over growing straight seedlings. However, I can see why commercial nurseries would not do it. It is time intensive, and about 10% of the seedling cuttings died. Of the straight seedlings, maybe 1% died, and that was from me over planting and neglect.

More comparison pics can be found http://aijoubonsai.wordpress.com/2013/0 ... seedlings/