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A Museum of Learning 
All bonsai are living plants and as such, they are growing and changing.  We are always trying to improve the health and beauty of the bonsai.

There are times throughout the year when the bonsai may look unkempt.  For example, branches may be permitted to elongate in order to strengthen or to modify the design.  You would think that these trees would be taken out of the display garden but we feel that this would deprive you of an education in the training steps for bonsai.  In this way, you will understand better that the art of bonsai is a process, not just a product.

Collection Connection Newsletter
As part of our continued effort to provide education concerning the art of bonsai to the followers of the art and to encourage interest from the young, we will be posting a PDF version of the Collection Connection. It is an 8 page newsletter filled with ideas and stories about work in the Bonsai Garden at Lake Merritt, events, and interviews.

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.

Frequently Asked Questions

Q. How do you pronounce bonsai?
A. It’s pronounced bone-sigh.

Q. I don’t understand all of the bonsai terms. Where can I find definitions?
A. There is a very good glossary on bonsaitalk.

Q. Are bonsai trees special clones, naturally miniature?
A. No. These trees would grow to full, natural height if planted in the ground.

Q. How do you keep them small?
A. The trees are kept small in two ways:

1. by limiting the amount of photosynthesis, accomplished by keeping the leaf mass to a minimum, by pinching, halving the leaves, or complete defoliation in summer (deciduous trees only). We pluck/cut needles of conifers to reduce foliage.

2. by limiting the amount of nutrients available to the plant. This is accomplished by root pruning every 1 - 3 years and not by limiting fertilizer.

Q. Are the trees starved to keep them small?
A. No, although that was done formerly by some. Most bonsai growers give their plants lots of fertilizer, organic or synthetic, and maintain appropriate size by pruning, pinching and root pruning. This system encourages growth and enables one to achieve a desired result sooner than if one were to limit nutrients.

Q. Do bonsai grow in regular potting soil?
A. No, they are grown in a soil that drains water very fast. Formulas differ among bonsai artists but the Bonsai Garden at Lake Merritt (BGLM) uses a Japanese soil called akadama with added materials such as expanded granite, charcoal, etc. to accomplish fast drainage. Akadama is available from various bonsai retailers.

Q. What is the wire for?
A. The annealed copper wire is placed on branches so that they can be arranged in pleasing ways. Wiring is kept on until the growth swells the branch. It is removed in order to prevent scarring of the bark. Branches will be wired this way regularly until the branch is old enough to maintain the styling and not return to its original configuration.

Q. I want to do bonsai but don’t have a yard. Can I keep it indoors?
A. No, with few exceptions. Almost all bonsai, except for tropicals, which are not traditional bonsai, are maintained outdoors at all times. The Japanese evolved the art with trees that worked in their climate, which is temperate: very hot and muggy in summer, cold in winter. Those who grow temperature-sensitive plants in cold winter areas, must protect them in various ways.

We are fortunate to have a wonderful gardening climate in the San Francisco Bay Area and can grow most bonsai readily. Our only lack is winter cold, although those far enough away from the Bay find that some plants benefit from their winter chill.

On the other hand, many who live in the summer high temperature parts of the Bay Area, may have to protect their plants with shade cloth.

Q. Are bonsai high maintenance?
A. It depends: on what you mean by that, how many plants you have, and how many qualified and reliable friends you have to care for them in your absence. There are four major areas of care: watering, fertilizing, pruning/pinching, and repotting/root pruning.

Watering - Bonsai require daily watering, with some exceptions, and twice daily watering in the summer if the sun is shining. Those who live in fog belts may water only once daily; those past the east Bay hills, for instance, may water three times daily. This immediately brings automated watering systems to mind. However, automated systems must be checked regularly and not depended upon completely. This is where those qualified and reliable friends come in. If you begin doing bonsai and join local clubs, chances are that you will make friends with people with whom you can arrange reciprocal watering schedules.

Fertilizing - the BGLM uses an organic fertilizer and applies it monthly. Some special plant conditions will require different fertilizing regimes, but they are typically done every 1 - 2 weeks. Others in the Bonsai community use slow release fertilizers, soluble fertilizers or traditional Japanese fertilizer cakes.

Pruning/pinching - Deciduous trees require pinching during the growth season to keep their compact appearance. They can typically go without pinching for a few weeks, even more. Conifer needles are removed and decandling done only in certain times of the year and generally there is a month-long window of opportunity.

Repotting/Root Pruning - this is done every 1 - 3 years, depending upon the density of the root growth of the plant. It is done only during the dormant season, which is short in San Francisco: November to February for most of us.

As you can see, it’s the watering that is high maintenance. If you think you can manage what has been described, consider joining a bonsai club and getting started.

Q. How can I get started in bonsai?
A. We conduct monthly demonstrations of bonsai creation and maintenance at the BGLM. They are held most months on the fourth Sunday of the month, from 1 to 3 pm. Check listings here and in local newspapers. We also recommend attending a meeting of one of the many California bonsai clubs, joining and going to workshops held by the clubs.

Q. There is rebar or bamboo on some of the trees. What is that for?
A. It’s there to bend the larger, woody branches. This is done on conifers and, as you saw from the Daimyo Oak, on some deciduous trees. Beginners and not a few experienced bonsai practitioners, find it amazing that trees withstand this treatment.

Q. In the tree gallery, there is a bonsai, #123, with no leaves on it during summer. What has happened to that tree?
A. The tree was defoliated, all leaves removed, in order to promote new smaller leaves and branching, or ramification, at the place where the leaves have been removed.