To those of us who live in the northern region of MABA territory, the Eastern Larch; larix laricina, is a favorite subject for bonsai. Fifteen years ago I harvested a larch from a small island in the middle of a river in northern Michigan. It was growing in pure river sand and silt. The tree was harvested and placed in a large wooden box filled with sand and peat. I allowed the tree to recover and develop for the next three years.
During this time the tree produced very small needles of a beautiful blue green color. Once the tree was placed in its first bonsai pot with a more traditional bonsai mix it started to take on the appearance of every other larch bonsai I had seen to this point. The needles became much longer, corpulent, and tended to sag. The next time the tree was transplanted I was more concerned with reducing several large roots than concerning myself with needle size, Consequently the soil mix was the same traditional bonsai mix I had used before. Surprise, surprise; the results were the same, long, corpulent and sagging needles.
After thinking the situation over I decided that I would change the soil mix on the next transplanting. Actually I had been considering this change for some time. I knew that this tree could produce very small and compact foliage. I knew that too much water was not the reason because the tree was growing virtually in a river and had, at the time of harvest, very small needles. The only real difference between then and now was the structure of the soil the tree was growing in.
When the time came, I took my normal bonsai mix, which consists of equal parts by volume of coarse silica sand, turface and composted pine bark mulch, and mixed it with an equal amount by volume of a fine but sharp silica sand used in swimming pool filters. This made up a mix that was more than 50% fine, sharp sand. That following season the needles started to show signs of reduction and the sagging had stopped.
The next spring, the second season since transplanting into the new mix, the needles became very short and once again regained the color the tree had when I found it growing in the river. At this point it would be possible to call this article complete because the results from this simple procedure are so dramatic, but there is much about pruning and pinching that I think needs to be said.
Once you have provided a soil mix more conducive to good bonsai culture, it is time to examine pruning and pinching techniques. I have noticed over the years that most people who have larches tend to let the new growth elongate then pinch it back in much the same way a pine is treated. This is less than ideal. The result is a crimped end with the remains of a torn needle or two. I don’t think it is necessary to explain why this is not acceptable.
The problem I see in most larch bonsai is the development of foliage pads. Most growers allow the new growth to extend too much before pinching, then they pinch as described above while the growth is still soft. Without a different approach, these trees always have that “just clipped” appearance.
The method I have adopted is better compared to that method used on spruce. The technique consists of allowing the growth to develop until the leader starts to extend out from the first circle of needles enough to grasp with the first two fingers and the thumb. The leader, which looks somewhat like a small paint brush, is then pulled straight out rather than pinched off. The result will be neat compact growth that looks as though it has never been touched, but instead, has grown that way naturally. Subsequent back budding is handled in the same way unless a lengthened branch is needed for some design purpose. Pruning is a simple matter of cutting back to, and a little above, a bud that points in the direction you want it to grow. It is also necessary to thin out the strongest areas of growth or the weaker areas will weaken further and eventually die. With an observance of the two key points I have pointed out here, larch make excellent bonsai worth the trouble to develop.
Larch will survive in a variety of conditions. They have been known to grow in dry sandy soils where nothing else will. They have been known to thrive in swamp conditions where nothing else will. However, they do not tolerate competition from other species. They will prosper almost anywhere in almost any condition that grants them solitude.
As far as general bonsai culture is concerned I have found my larch likes and responds to an abundance of water and full sun. I fertilize about every ten days, alternating between Mir Acid, and Peters 20-20-20. The larch is winter hardy down to temperatures that would kill almost anything else. I place mine in an area that shelters it from the warming effects of the sun and blocks the drying, winter winds.