On June 27, 2017, Redwood Empire Bonsai Society (REBS) held its monthly meeting at the Luther Burbank Art & Garden Center, Santa Rosa, California, with guest bonsai artist, instructor and author Jonas Dupuich, who led a demonstration and discussion on the decandling of pines.
Decandling was defined as the technique for the removal of spring growth (candles) from pines in order to stimulate a second push of growth in the summer months.
The time period for decandling pines is in the middle of the growing season and dependent upon the weather and environmental conditions. For example, in the State of Washington decandling will take place in early spring (May, June), and in the State of Texas it would take place later in mid-summer (late June, July). In the San Francisco/Bay Area, decandling usually is done in early June and July. Timing relates to the amount of growing season remaining after decandling to help the second push of new growth.
Jonas discussed the purpose of decandling pines as follows:
1. Stimulate back budding
2. Improve branch density
3. Shorten internodes
4. Regulate vigor
5. Promote balance
6. Reduce needle length
Jonas cited that decandling pines only started in Japan during the 1960’s.
There are certain steps to take when decandling pines. Examine the tree to determine if it is healthy, that it has been fed sufficiently and that the trunk size is desirable. Experiment with the timing by decandling on June 15 and then make adjustments in the timing the following year based on the results. The technique for cutting candles used by Jonas is to use scissors, cut straight across and leave two to three millimeters of new growth. You do not want to cut into last year’s needles, so leaving a small stub is appropriate. In doing so, you save the advantageous buds. Stop feeding and start again in the fall. After decandling and needle pulling you need to watch watering carefully and reduce the amount of watering.
Jonas covered a number of variations and related decandling techniques; leave stubs on the vigorous shoots, pull needles on vigorous shoots and cut less of the vigorous shoots before cutting vigorous shoots.
Jonas reminded everyone that different instructors will use these variations for decandling purposes.
If you come across a single candle without last year’s needles, there is no potential for advantageous budding, so leave the candle in place.
Wiring can be done after decandling and pulling needles, but it is usually done in November and December.
Watering should be cut back after decandling. The best practice is to dig down slightly into the soil and if you feel moisture, do not water.
Jonas said wounds on pines are inevitable and so be sure to have them in the back of the tree.
Pines take full sun.
Jonas brought three Japanese black pines to the demonstration. The first black pine was decandled and older needles removed. The second tree was healthy and ready for decandling and needle pulling. And, the third tree was pre-bonsai to be raffled off.
First black pine: The tree showed where the needles were all cut and removed. Last year’s needles were reduced to seven or eight pairs for each branch. The older needles were all pulled. Second black pine: This tree was used to demonstrate cutting the candles and pulling needles. Again, last year’s needles were pulled but leaving seven to eight pairs of needles per branch. The third black pine was raffled off and won by REBS member Mike Nelson. Upon winning the third tree, Jonas and Mike worked on the tree, allowing Mike to cut candles and pull needles. Since the tree had many lower branches, Jonas reduced the number of branches by cutting and removing unwanted branches. As a result, Mike’s black pine was on its way to becoming a bonsai.
Note: Jonas is the creator and author of the bi-weekly blog “Bonsai Tonight” https://bonsaitonight.com/. You can subscribe to every Tuesday and Friday blogs and automatically receive his blog emails by visiting the above website.
– George Haas