Common Terms

Repotting 101

Repotting may be the single technique that beginners worry about.  We have a series of photos of repotting during the Fall 2007 season to give you an idea of the process.  Click here to view photos.

Cedar Group # 120
Why are all the trees of this composition different in color and the needles of different lengths?  Because this clump started life in separate pots from different genetic stock.  Even seeds from the same plant may produce different looking trees.  At a young age, all of these trees looked alike.  As they matured, the individual characteristics became evident.

  1. In nature, a forest or clump of trees of the same species will have the same characteristics in color and shape.
  2. If you are trying to produce a clump or group of identical trees, start with cuttings from the same tree.
  3. Grow them in different-sized pots to achieve a difference in trunk size, height, etc. and then put them together in an arrangement.

Defoliation
What is defoliation?  It is the removal of all leaves.  Defoliation in an important step in improving deciduous trees.  It should be done after the new leaf has matured, become harder.  May and June are the best months in the San Francisco Bay area to defoliate.  In very warm or hot areas, it is better to defoliate earlier, after the second set of leaves has hardened and before the real heat begins.  When you visit the garden in summer, see whether you can find trees that have been defoliated.

How do you defoliate?

  1. Cut the leaf off at the base of the leaf stem or petiole.  The axillary leaf bud will be stimulated into activity and new leaves will quickly form.
  2. If you leave a long petiole (leaf stem), the axillary bud will be slower in developing and the new leaf will take longer to form.

Why do we defoliate?

  1. Bonsai look best when the foliage is as small as possible and in proportion to the size of the tree and the branches have ramification (image).
  2. Defoliating produces a new set of leaves which are usually smaller.
  3. The resulting branch will ramify much more quickly.
  4. Defoliation is done only on healthy bonsai

Wisteria Bonsai Culture
If you visit our garden in the spring, you will see many things in bloom, including our wisteria bonsai.  Wisteria in bonsai culture are all about flowers in spring.  In the summer, the plants produce long runners, which we leave on the plant.  Why do we leave the long runners on the bonsai plant?

By leaving the runners on the wisteria through the summer, we are allowing the plant to strengthen and to create flower buds for next year.  If we were to remove those runners, the plant would try to make more runners, thus diverting energy from forming flower buds.  The runners are twisted into a circle to keep them off other plants and the fence and to make them more manageable.

In August, when the wisteria shows signs of heat stress, the leaves fold to retain moisture.  At this time, the runners and seedpods are removed.

Our wisteria, #153, was repotted and completely bare rooted in early January 2006.  During this procedure, we found that there were two trees.  We separated the smaller tree and transplanted it as a cascade.  It is on display as #153B.