Bonsai tree

Source: Bonsai Tonight
How to create seedling cuttings – Japanese black pine

I began to describe the steps required to grow Japanese black pine bonsai from seed last year, but left off just after planting the seeds. I ended up abandoning last year’s batch as only a dozen seeds sprouted. I tried again this year with much better luck. Due to a cold spring, the seeds took a long time to sprout. After maybe three months, most of the seeds I’d planted were growing well. It was time to make seedling cuttings.




Pine seedlings typically produce a single tap root that reaches downward and grows vigorously to provide a good anchor for the tree. Although they are good for forest trees, tap roots are not as good for young bonsai.

A couple of generations ago, bonsai enthusiasts figured out that cutting the tap root produced a number of lateral roots. As these lateral roots developed, the young trees grew faster, denser, and produced a flared trunk base that is often desired in pine bonsai. Many pine bonsai have been produced in Japan by this technique, and the technique has been gaining popularity in the US for at least 20 years. I first learned about the process from Boon Manakitivipart and Bonsai Today numbers 12 and 20. The techniques below represent knowledge I’ve picked up from Boon, Bonsai Today, and many years of practice – I started my first batch of pine seedlings over 17 years ago.

The basics of the process are simple: make cuttings out of young pine seedlings. I begin by filling a nursery flat with 4″ plastic pots and adding the soil, one layer at a time.







I will plant the pines in a pocket of sand to keep the cuttings moist. I watered the soil and then used the handle of a bonsai trowel to create craters into which I poured fine sand.







Once the sand was in place, I again watered the soil and created small holes with large gauge copper wire. When the cuttings are ready, I’ll carefully drop them in these holes.



The next step is creating the cuttings. I begin by carefully uprooting one cutting at a time. I try to use seedlings that are healthy like the one on the right in the photo below. The two seedlings on the left are weak – I did not use them for cuttings.





There was considerable variation among the uprooted seedlings. Although I typically worked with one at a time, I did a few at once for this photo.



I made the cuttings with a razor, leaving about 3/4″ of stem below the first needles. After making the cut, I quickly dropped the plants into water to keep them moist.







Before planting the cuttings, I dip them in powdered root hormone to help the cuttings develop roots.



I approach the planting of the cuttings with care. After setting the cutting in one of the holes I created, I gently pressed on the surrounding sand to close the gap. I tried to move the cutting as little as possible to avoid disturbing the hormone. I also skipped on water when I was done to avoid washing the hormone away.





I’ve kept the seedlings outside under shade cloth for the past five weeks. I’m slowly moving them into spots where they get more light, and I’m misting them several times a day – more when it’s hot, less when it’s cool out. That’s the recipe for the time being. Once the seedlings start growing quickly – evidence of new roots – I can begin to fertilize and continue to provide the seedlings with more and more light.