By Thomas Matkey (Glendora, California) Journal contributing writer

            Iíve made some screening boxes for the updated soil configuration.  There are five sizes of screen.  One-half inch, three-eighth inch, one-quarter inch, one-eighth inch and one-sixteenth inch.

I used four boards for each box.  Each board is 12 inches long using 1X3 inch boards.  Youíll also need 16 number 6 screws 2 inches long for the corners and 25 number 6 screws 1 inch long for the bottom strips.  I made the boxes one square foot in size.  They donít have to be square; they can be a rectangle if you choose.  I made mine square because the screen I have was square.  No other reason.

        Left:  Boards are 12 inches long and 3 inches wide.  The screens are hardware cloth available at a decent hardware store.  I was able to buy hardware cloth in 1 foot by 2 foot lengths.  Your local big box stores will only carry large rolls, so check out your local independent hardware stores such as an Ace Hardware.  They will sell it by the foot. Wearing gloves while working with hardware cloth is a really good idea.  That stuff will cut your fingers if youíre not extremely careful.  In my pictures, Iím not wearing gloves because that screen was plastic, not wire.  For the other boxes with wire screens, I wore gloves.

        Center:  Cut a strip off the boards about ĺ inch wide.  These will be used for the bottom of the box to hold the screening and also to keep the sharp edges of the screens covered.

         Right:  Take two of the boards and put them at right angles to each other.  Drill two holes in each corner for 6 X 2 inch screws.  The holes are not centered, but are what will be the top of the box.  One screw goes in the center and one screw goes below that.  Do it the same way on each corner.  Itís done that way so that when we screw the bottom strips to the box, we wonít have screws in the way.  The screws are countersunk so they donít protrude from the wood.

        Left: Screwing the corner together.  Thereíll be a second screw just above the first one.  About in the middle of the board.

        Center:  If you want to make a square box, make sure the boards overlap each other as shown in the picture.  If you donít the box wonít be square, it will be a rectangle.

        Right:  Trim the hardware cloth to fit the box youíve just made.  Donít have any of the wire protruding from the box.  It will cut you in a heartbeat!  Attach the screen with some staples.  The staples will hold the screen in place so it doesnít move while youíre putting on the strips.   The screens are mostly held by the bottom strips.  Make sure thereís no wire protruding over the edge of the box.  When you do the stapling, try to estimate where the screws will be later.  Put the staples where the screws wonít be.

          Left:  Attaching the bottom strips.  Put the ĺ inch strips on top of the screen and drill countersunk holes for the screws.  Drill through the bottom strip, screen and into the side.  This is where you use the 1 inch screws.  Countersinking the screws eliminates the possibility of catching your fingers on protruding screws.  I used 5 screws per side. You can see here why the corner screws are spaced so the bottom screws donít hit them.

          Center:  I rounded off the corners top, corners and bottom for more comfort when using the boxes.  I also marked each box with the size of screening.  I learned later that when the box is full of media, you canít tell which size the screen is!

           Right:  Completed box from the top.


           Left:  Completed box from the bottom.

           Center:  Boxes stack up easily when theyíre the same size.

           Right:  Sifting the media is easy, but messy.  Donít do this inside anywhere.  Dust goes everywhere and so do the pieces of the smallest particles.  Also, this is another time when youíll need gloves.  Many of the pieces stick halfway in the screens.  They will cut you if you run a bare hand over them.  I stacked the boxes in a silicone garden bucket that just fit the screens.  The plastic is bendy and I used the handles to shake the whole thing.  I did it on an old bathroom shower curtain liner.  It made it easy to gather up the pieces that escaped from the bucket.  Boxes stacked in silicone bucket, ready to rock and roll!  Donít put too much media in at a time.  It may fool you as to how much youíve poured into the top.  Most goes through to the 3d box and you canít see how full the box is.  If itís too full, shaking it wonít let all the pieces get to the screen that should go through.  I put too much in at first and had to unstack the boxes and use my hands to stir up the media so all got a chance to be screened.  Thatís when I cut my finger (not badly, more of a paper cut) on one of the very small pieces caught by the screen.  Thatís why I recommended gloves earlier. In addition, having smaller amounts of media caught in the screen makes it easier to pour out the caught particles into something.  I used plastic pails even though they were far too big.  It did make it easy to empty the screen though.


           I obtained a 3 gallon quantity in Fuku-Bonsai's special postal flat rate box deal and ran all through the 5 screens.   Youíll end up with six different sizes of media.  So be sure to have six different containers on hand to put them in.  I ended up with the following estimates of the amounts:

           1/2 cup caught in the ĹĒ screen

           1 1/2 cups caught in the 3/8Ē screen

           1 gallon caught in the ľĒ screen

           1 gallon caught in the 1/8Ē screen

           1Ĺ quarts caught in the 1/16Ē screen

           1 quart got through the 1/16Ē screen 

             Left:      Particles caught by ĹĒ (left) and 3/8Ē (right) screen

            Center:  Particles caught by ľĒ (left) and 1/8Ē (right) screen

            Right:     Particles caught in 1/16Ē (left) screen and what manages to get through the 1/16Ē (right) screen. 



             Some of our customers live in urban environments where they don't have need for a lot of potting materials and this is especially so for those joining our Fast-Track Study Group that are moving towards creating MINI-BONSAI!  Those that live in apartments don't have a lot of growing area but they can have a nice collection of mini-bonsai --- especially if they qualify for the Fast-Track Study Group to have access to the Premium Prepared Bonsai Stock that is ideal to go straight into mini-bonsai and to start refinement to develop very compact growth and small leaves. 

             We have just begun developing such techniques at Fuku-Bonsai and the results are impressive! Thomas Matkey is meticulous, really handy with tools, and experienced at putting together instructional manuals.  So I asked him to put together a report on making screens and a comparison report on two potting methods that also appears in this issue of the Journal at:

             Fuku-Bonsai's general potting media has 3 components: 

        1.  Coarse Bottom:  100% larger porous black lava high-velocity pumice ejecta for drainage.

        2.  Body Media:  3/8" minus including dust -- 75%-80% lava high-velocity pumice ejecta with 20-25% organic matter (coconut husk in various grades AKA coco-peat),  Nutrient Granules, and other soil amendments.

        3.  Top Dressing:  Coffee grain size lava high-velocity pumice ejecta that goes through the 1/8" screen and caught in the 1/16" screen to create an attractive surface. 

              This is the basic mix we use in the nursery in almost everything with adjustments when needed.  Because it is extremely granular,  it's probably the fastest draining bonsai media in the world and ideal for True Indoor Bonsai as potting media does not easily dry indoors and this results in plants being over-watered and develop root rot.  This method is for standard potting in which the surface flat and is slightly below the rim of the bonsai pot.  But if it is used when you're trying to contour the surface, when watering, the mounded up media will just wash down flat.  To some extent you can use an aluminum foil or other collar to hold the material in place until roots develop and holds it.  A preferable method is being developed and used as we move into finished trees with contoured surfaces and Thomas's report addresses this method that will increasingly be used by those in the Fast-Track Study Group. 

            ~~~David (

***  Return to the September issue of the Journal of Tropical and True Indoor Bonsai
***  Go to the Mid-Pacific Bonsai Foundation website
***  Go to the Fuku-Bonsai website
       © Mid-Pacific Bonsai Foundation and Fuku-Bonsai, 2014