NO. 98 - MARCH/APRIL, 2006

SEASONAL SUGGESTIONS

PREPARATION, POTTING AND PRODUCTIVITY

By

MARTY MANN

After a welcome rainy season, we now prepare for a serious period of repotting. It is time to energize your thoughts and efforts. If you have already created your supply of good basic potting soil and clean pots, you should be ready to go.

Your projects is threefold:

            • moving pre-trained material from nursery cans to selected bonsai pots, either for further training or for show.

            • transferring trees that are already potted into larger and/or more decorative pots due to changes in the basic shape, size or design of the trees.

            • repotting trees that are ready to be refreshed with new soil. Remove excessive root growth to generally improve their health.

The process of potting and repotting is very important at this time. Part of the responsibility of maintaining an attractive and healthy bonsai collection is the never-ending process of providing the proper growing envi­ronment. Your best guideline is not just the question of the recommended time to repot, but more so, the need to repot based upon the condition of the tree. Depending upon the particular weather conditions in your area during recent weeks, signs of growing activity has already begun. It’s best to repot before any significant signs of bud swelling has started. This is especially true of fruiting and flowering varieties. Most of these, especially deciduous trees, benefit from annual or frequent repotting. Don't overlook the smaller Shohin pieces. It's important to be watchful of this class of bonsai since they quickly reflect your ne­glect.

Introducing a small amount of bone meal in all new potting soil mix is becoming popular. The early presence of the minerals in the soil encourages faster and healthier root growth. Bone meal is high in phosphoric acid (formula 1-30-0) and neutralizes soil salts. In March, resume a regular schedule of feeding with the addition of cottonseed meal that provides the necessary source of potash (formula 7-3-1) and restores the acidity. A small amount of blood meal provides a fast acting source of nitrogen. Each of the elements in a fertilizer mix encourages growth and produces microorganisms to nurture the trees and keep them green and healthy.

California needed rain. Bonsai flourished during the last few months of persistent, clean water that flushed the alkalinity and accumulated harmful salts out of their system. Rain allows fresh spring growth to begin and new green moss to show.

Care must be taken to protect potted, soaked plants as well as those in the ground. Excess water can actually be damaging. Potted material becomes compacted. Walking on or digging a wet garden area also compacts the soil. Soil that is compressed eliminates the tiny air pocket that lets the soil breathe. This space normally allows excess water to drain through the mixture and prevents a soggy mess that creates root rot.

If you were able to observe your potted material during these recent rains you may have notice that some of them just puddled before they drained--a sure sign that your potting soil is either worn out or was prepared without enough aggregates to encourage good drainage. Be sure that these specific pots or cans are repotted to improve this situation. If your planting areas stayed flooded too long remember where the low spots were and rake them level. If crusts have formed on surfaces from mulch or old fertilizers break them up to allow the drying action to penetrate below the soil level.

The drying process begins--the potting season is upon us. Just as warm sunshine moves the dormant buds, signs of spring emergence suggests the need to get to work. It is time to look at all of your trees. Hopefully, you already marked the potted material that needs to be done this year, you prepared a fresh supply of basic potting mix, selected new pots and observed wiring needs. We do not repot for aesthetic reasons alone but for the health of the tree. The ma­terial will usually show you that it is not happy with its soil. A change promotes vigor, good color and good health.

Bonsai, ready for repotting, should be somewhat on the dry side. The tree will be easier to remove from the pot. The combing of the root ball, after cutting away the traditional 1/3, will free the fine roots and encourage regrowth. While repotting, don’t allow the fine roots to be exposed to the sun or drying winds--keep a spray bottle handy. Be sure that your new soil mix has been screened to remove the harmful fine dust. Newly potted material should be kept in partial shade for a week or so and then moved out into full sun to allow the roots to redevelop.

Water, deep into every root ball, creates a haven for a surge of fungus growth. Treat everything as if it is already infected. Most all-purpose fungicides controls leaf mildew. Topical sprays of Ortho Garden Disease Control are an excellent deterrent for pine needle cast infections as well as problems on most other conifers and deciduous material.

It's still not too late to propagate by cutting or grafting. Cuttings are made with dormant material that is just showing spring growth - most will do better if the material has been allowed to harden first. Seedlings and small trees are collected from the wild if you have access to areas where you can get the proper permission. Use a well-drained pourus potting mix for collected material to encourage new root growth. During repotting activities it is wise to study the trees. Remove excessive growth, crossing branches and long internodes that have been overlooked during the dormant months.

Early spring is the best time to propagate tropicals such as banyons and figs. It 's time to sow seeds of deciduous trees that have been kept cool in your refrigerator for stratification.  Seeds can be planted in April or May. Take cuttings of junipers and prepare air-layers as well.  Use previous season's wood.

By controlling the amount of light exposure, you give young trees you can hold back or push these transplants. Keeping the plants in a cool area, with little sun, slows leaf development. This is a particularly good technique if you are timing your leaves or flowers for a show.

Postscript

For you computer folks, just remember, great bonsai chat groups grow from little icons.  Fax is stranger than fiction and a journey of a thousand sites begins with a single click. 

Marty Mann