Fuku-Bonsai's 3-component potting media is a large part of the success of our workshop packages.  It utilizes a rare volcanic pumice found only on the Big Island of Hawaii.  There are several types and the best comes from a quarry pit in Kapoho.   It is used extensively by the Big Island's floriculture industry and it has been cleared for use in the certified export nursery industry since 1973. 

Lava ejecta 1 Apr 2003.jpg (33085 bytes)      Jurisdiction for exporting the material fell between the governmental regulatory crack between the Hawaii State Department of Agriculture and the Animal & Plant Health Inspection Service (USDA-APHIS).  While it clearly was okay to ship plants growing in it, it took a while to clear the shipping of the our potting media separate from plants! The regulatory process began with inspection of the quarry to assure that there were no pockets of soil.
Lava ejecta 3 Apr 2003.jpg (23813 bytes)      This quarry has been supplying our nursery for many years and a variety of screens and crushers produce bulk loads containing our specified ratios of various particle sizes.  The USDA inspectors go to the quarry and inspect the material before loading on large 40+ cubic yard tractor-trailers. Because of the screening of each size, then combining various sizes in specific ratios, each load of our "Fuku-Bonsai standard" is consistently the same.  When delivered the load fills our entire 24' long x 12' wide concreted cinder holding bin.
Lava ejecta 6 Apr 2003.jpg (34184 bytes)       Most of the material goes out under our Hawaii State Burrowing Nematode Certified Nursery Program stamp.  USDA-APHIS created a program specifically  so Fuku-Bonsai would be in compliance with all governmental regulations and when we send our media without plants,  we are required to use this  Limited Media Permit handstamp.  The stamp is also utilized to clear the materials that are used in the Micro-Lobster aquascaping and bacteria inoculated filtration materials. 

                This material is "high-velocity pumice ejecta" created when lava flowing underground hits an underground water stream.  The resulting steam and cinder explosion sends a spectacular fiery fountain over 1,000' high into the air!   This creates a very porous material filled with tiny holes throughout.  It is very light and some pieces will actually float! In Hawaii, the common name is "Black Volcanic Cinder" and entire trailer loads are sent by barge to supply the larger Oahu nurseries.  The raw unscreened material is bagged and sold in garden centers.


PremiumKeikiBonsaiWkspPackage2001.jpg (17526 bytes)         We first offered the media as part of a Premium Keiki Bonsai Workshop Package and this became the most popular workshop taken by Fuku-Bonsai Kurtistown visitors.  We do extensive additional screening and measuring to provide three different potting components in the proper amounts to fill a 8"diameter x 2" deep round Fuku-Bonsai plastic pot that needs about 1 quart of potting media. The package included all other needed items and most adults would have no problem completing the workshop with the aid of the workshop handbook.

                Fuku-Bonsai workshop interest continues to increase.   There is a growing realization that Fuku-Bonsai is the more knowledgible source of TRUE INDOOR BONSAI information and assistance in the world! Premium Keiki Bonsai Workshops continue to be the most popular.  Our Living Lovable plants are the smallest houseplant prepared bonsai stock available and ideal for workshops that pot it into our #8 Conversion Kit. Increasing customers are ordering the advanced workshop package of a potted #8 size Living Sculpture to pot into our #17 Conversion Kit to quickly produce a high quality larger bonsai!

                We are suppling more bonsai clubs who realize that most beginners find traditional outdoor bonsai to be much too difficult.  Our workshops become great club activities in the hottest summers or the coldest winters when there is limited traditional outdoor bonsai activity.  Increasingly general garden clubs and youth groups are being introduced through TRUE INDOOR BONSAI workshops!

                It does not take a bonsai expert to lead our workshops.  All it takes is a desire to teach and share!  If you purchase a workshop package and succeed on your own,   you should be able to lead a garden club, church, or youth group workshop!   Please contact Fuku-Bonsai for more information including discounts that could be used for fund-raising and bulk purchase of workshop materials.  We are encouraging bonsai clubs and potential workshop instructors to develop an equivalent potting media to further reduce costs. Individuals with some bonsai experience order a workshop package to experience and understand how to make up and use a fast drainage gravel-type potting media.  They then put together a comparable media with less costly local materials,   utilize less costly training pots, and order only the prepared bonsai stock from us.  In doing so, they greatly reduce costs while continuing to have high-success and the high-potential of our superior prepared bonsai stock!

                We offer only a premium 3-component mix that includes a proportional amount of coarse bottom media, a body media blend, and a fine top-dressing.   The screening and packaging is very labor intensive, but this is exceeded by the cost of shipping and handling!  We have tried to get other bonsai companies within the continental United States to produce this mix and make it available at lower costs. But none was willing or able to meet our standards and criteria and we rejected all samples.  Aggregate portions included Haydite, Turface, decomposing granite, lava cinder, etc.  So in the end, even though our material is expensive, we still believe it is the best available.  Our customers seem to agree even when we offer to assist in formulating a less costly mix from locally available materials. 


                For those who may be interested or able to make up a comparable indoor bonsai potting media to supply a growing hobby, to assist in leading group workshops, or to supply other members of bonsai clubs or groups,  the following are specific details.

               COMPONENT #1 (Coarse bottom aggregate only):  1/2" to 3/4" pieces of high-velocity pumice ejecta only.  Passes through a 1/2"x1" screen and caught in a 3/8" screen.

               COMPONENT #2 (Body media blend of 75% aggregate and 25% organic matter): The aggregate material goes through a 1/2" or 3/8" screen including all dust. This is blended with 25% organic matter with our preferred material being a  coarse grade of Canadian spaghnum-peat moss.  To this mixture, we add 6 oz. per 5 gallons of body media blend of coarse MagAmp (magnesium ammophosphate 6-40-7).  MagAmp is a slow release chemical bonded fertilizer that will have a very controlled nutrient release over a full year.  The body media blend should be made slightly damp before potting. 

                COMPONENT #3 (Fine top-dressing of aggregate only):  Screen material through a 1/8" screen and use the particles that are caught in a 1/16" screen.   Discard the fine dust that goes through the 1/16" screen. 


                COMPONENT #1 (Coarse bottom aggregate only):  This component forms the drainage layer. First install the tie-down string or wires through the drain holes. In most cases the material is large enough that hole screens are not necessary.  The coarse bottom aggregate is mounded in the center of the pot to "bridge" all drain holes.  A plastic film that is large enough to cover 1/2 of the drainage layer assures that the finer body media will not migrate downwards and clog drainage.

               COMPONENT #2 (Body media blend of 75% aggregate and 25% organic matter): When potting,  first fill the pot even to the top of the drainage mound with just an 1/8" of media over the plastic barrier and as much as an inch around the edges.  Pound and firm this down with the bottom of a can or block of wood.  Place the root pruned plant on this compacted layer, tie down securely,  then place enough body media to fill the pot.  With a trowel or spoon,  press down and firm the media. Add more media if necessary so the soil level is about 1/4" below the rim of the pot. 

               FIRST WATERING:  Sit the potted plant into a pan filled with 2" of water for about 30 minutes. Allow the water to enter through the bottom holes to totally saturate the media.  Drain and after dripping stops,  using the trowel or spoon to again carefully press down and level the surface.

                COMPONENT #3 (Fine top-dressing of aggregate only):    This coffee grain sized pieces "seals" and visually dresses up the surface.  Some growers omit this step as it is primarily cosmetic.  They save this hard-to-obtain material for when they want to formally display their bonsai. 


                THERE REALLY ARE NOT SECRETS!  It should be possible to locate bulk materials that will greatly reduce costs.  It may be possible for bonsai clubs or local bonsai professionals to supply materials that meet these criteria.  Indoor houseplant bonsai potting components are very different from the materials used by those who grow traditional outdoor bonsai.  This is because plants dry out more slowly indoors and roots will rot if the outdoor potting media is used indoors.  Aggregate sizes are much larger for indoor bonsai. 

                All potting soils contain only three major items:  aggregate, clay, and organic matter.   No clay in any form is used for indoor bonsai as it will prevent optimum fast drainage.  To test the aggregate component, place a small amount in a glass of water and stir vigorously.  If it desolves or takes a long while for the water to clear, the material is unsuitable or must be washed and dried before using. The organic component can be pine bark, composted redwood bark, chopped coconut husk, chopped spaghnum moss, shredded tree fern, etc.  Each has different advantages or disadvantages to analyse and fine-tune a specific 3-component media mix.

                Our 3-component system differs from traditional outdoor bonsai practices in which the coarse layer is on the bottom and each layer containing only a slightly smaller particle size with the finest on top. Although there's a lot of work to screen several different particle sizes, the effort is often nullified when dibbling and probing to get the material between the roots and filling all air pockets brings up the coarse material and the fine material migrating down to clog the drainage layer.  Compared to this type of potting procedures, our potting method creates a distinct separation of our coarse bottom layer with a piece of plastic film to separate the body blend.  In having such a distinct separation,  a "perched water table" is created.  It is impossible for water to puddle on the bottom of the pot.  Yet the blended body media holds sufficient water in the form of moisture.

                Our 3-component system also differs from a uniform single component potting mix used throughout the standard nursery industry.  It is far more economical to use a single potting media component and to omit the coarse bottom drainage layer. But without that coarse bottom drainage layer, you'll either have good or poor results depending upon whether your single potting mix exactly meets the needs of the plants.  All plants do not have the same requirements.  By utilizing a combination of an integrated mix over a coarse bottom "hill" with a "separator,"  the tree will tell you how to further adjust your potting media!


                After a year or two, your plant will either be growing well or not.  If it's growing poorly, the odds are that your potting mixture needs adjusting.  If you take the plant out of the pot, you can quicky evaluate your soil mix.  If you have only a few roots and they all shoot for the bottom and the bulk of the mass is in the coarse bottom layer,  your body media blend is not holding enough water and the percentage of the organic water-retaining component should be increased.  This will create a slower draining media and keep more of the roots in the body media blend.

                If you only have a few roots that are only in the body media,  the media may be too slow draining and the roots are rotting.  Reduce the amount of organic matter and/or screen out some of the very fine particles from the body blend. 

                With good media and potting procedures, roots should fill the entire network of the body media blend first.  As it gets to the point of becoming pot-bound, roots then begin circling the pot and invading the coarse bottom layer.  Generally in tropical climates, it will take two years to reach this stage.  Depending upon the specific growing conditions,  it may take three to five years for plants growing indoors 100% of the time. Because of the relatively slow indoor growth,  it is not necessary to repot plants as often as necessary for outdoor bonsai.  But repotting may be desirable if there is good foliage growth and the plant gets pot-bound. This will be covered in a future lesson.               

                All best wishes for YOUR success!  ~~~David W. Fukumoto (September 21, 2004)

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Fuku-Bonsai Inc. 2004    

      PO Box 6000, Kurtistown, Hawaii 96760        Phone (808) 982-9880
      FAX (808) 982-9883     Email:   sales@fukubonsai.com     URL: www.fukubonsai.com