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Information on how Kaizen Bonsai soil products are described, graded and packaged

Kaizen Bonsai have been selling a wide range of soil products for more than 20 years now. In that time we have settled on a number of suppliers that produce consistent grades of quality product that we use on our own nursery and so we know the products well. Within retail horticulture there is a lot of confusion as regards how growing media are graded, described, packaged and sold. Over the years our customers have been very happy with what they receive from us to the extent we are now the largest supplier of bonsai growing media in the UK with a turnover of dozens of tons of material annually. In order to clarify how we sell our products, how they are graded and packaged we have produced the following notes as general guidance. By virtue of the fact our products are largely natural and organic variations are unavoidable over time, what follows is our best effort to help you understand those variations.

Most of our products are graded by their manufacturers. This basically means they are sieved twice in order to produce a broadly consistent particle size. Most of our products have a mesh size as part of their description. For instance standard Akadama is listed as 2-8mm. This means that when it was graded it was passed through a mesh of 2mm square size in order to remove smaller particles. It was then put through an 8mm mesh in order to remove the larger parts. The result is a product that is broadly between those two sizes. That does not ensure the bulk is of lager size or on the other hand of a smaller size. All this figure indicates is that the NOMINAL size will be between these two extremes and in an ideal world the bulk of the material would be in the middle range but this MAY NOT BE THE CASE. Typically very little material at the lower end will be included for the reasons stated below.

Where larger screen sizes are concerned, say 7-13mm, bear in mind that a 7mm square sieve mesh has a diagonal of 9.9mm and a mesh of 13mm has a diagonal of over 18mm. Therefore it’s likely very little material at 7mm may be included as much of it will have passed through the mesh diagonally. Also you can expect a good part of the material to be larger than 13mm seeing as the 13mm screen will pass material up to 18mm. It’s also entirely possible that long thin particles will pass through the same screen on end. For coarse graded materials like bark and pumice it’s entirely normal to see particles 20-30 or ever 40mm long by (in this example) 18mm wide as they will pass through the screen. This is more obvious with the larger particle product because the difference in the screen size and it’s diagonal is relatively greater than that of a smaller screen.

If you need a product with a perfectly even particle size you will need to buy more than you need and sieve and grade the material yourself.

Fines in regard to horticultural products refers to the very fine material we might also call dust. Depending upon the nature of the material it may or may not be beneficial to include degrees of fines into our growing media. For instance organic bark dust is very useful as a moisture retainer where as a dust from clay products COULD reduce drainage and in large enough quantities COULD be detrimental to a growing medias performance. All of the growing media products Kaizen Bonsai sell have had fines removed, all having passed through grading process as noted above. However this DOES NOT indicate they are entirely free of fines and dust. As produced our Chipped Pine Bark has less than 1% by volume of material below the minimum mesh size of 5mm. However because most of our products are produced from large material i.e: bark from trees, pumice from a mountainside and again Kanuma from a huge volcanic mountain deposit they have to be crushed or shredded. This leaves the products rough in texture, cracked and fissured and many are quite abrasive (the primary use of pumice is as an abrasive). Therefore in processing, packaging, settlement and transportation a varying and unavoidable degree of fines will be produced. Depending upon the nature of the material more or less fines may be present at the final point of use. Any figures we state in regard to fines is that given to us from the manufacturer and relates to the moment at which the material has been produced prior to packaging and transport.

In general, based on practical (bonsai) experience we never now sieve material to remove dust. Sieving a product like Akadama will simply result in the production of more and more dust until there is very little left. Dust is easily and quickly removed from all the materials we sell as follows. Simply pot your plants in the normal way you do using un-sieved product and once complete put the pot on a bench or stand that will allow you to see the water emerging from the pots drainage holes. Simply flood the pot with running water until that water appears clear and free from sediment where it emerges from the pots drainage holes. Once the water runs clear your plant will have a good clean and perfectly functioning growing media in which to thrive.

Where we state a particular moisture content this would have been given to us by the manufacturer at the point of production prior to packaging. Where we state a product is ‘dry’ this is a relative term and means that the material supplied should feel fairly dry to the touch. As an example Chipped Pine Bark looks and feels quite dry but chemically, as produced, has nominally 42% moisture content. Products that are kiln fired as part of their production like Moler and S-Te Bonsai will feel dry but may have a quite high absorbed moisture content and this WILL vary depending upon the prevailing conditions. Where a product is shipped during hot conditions some condensation may occur within the packaging. In cold conditions some condensation may appear if the product is moved to a warm place.

Many of our products are from quarry sources and these can have wildly varying moisture content. There is no point in spending time and money burning fuel to dry these products for horticultural use where the media will end up being watered. Therefore products like Pumice and Lapillo may have anything from very little water content to a high water content depending upon the conditions in which they are processed. Ultimately this is of no consequence where the product is intended for horticultural use. The moisture content of our products will vary dependant upon many factors and you should be prepared for this.

Horticultural media products are measured out and sold in two possible ways. Firstly by weight and secondly by volume.

Where a product is manufactured in such a way that it produces a consistent material in terms of it’s uniform weight and moisture content it is normally sold by weight, this being the most reliable way of determining that you receive a consistent amount of product. Weights stated are correct at time of packaging but could vary slightly due to moisture ingress or loss over time. 1 kilogram of product is a measurement of it’s weight and bears no comparison it it’s volume. A kilo of rock weighs the same as a kilo of feathers but the later would be much larger in volume. Our packages are generally 5 or 10Kg where weight is concerned but this bears no comparison with products sold by volume. As an example 14 litres of bark is much smaller than 14 kilograms because the material is light weight and bulky. Kaizen Bonsai product weights are guaranteed at time of production and packaging to be within tolerances of -0/+5% but may vary post shipping due to environmental conditions.

Where a product varies in it’s weight and bulk density volume it must be sold by volume. Materials that are very compressible, like multi purpose compost are sold in the UK by litre measures. This gives the customer a consistent measure of product for the price and is not readily effected by reasonable fluctuations in moisture content or density variances in natural products like bark which could adversely effect a measurement made by weight. IE: Wet compost weighs more than dry product and so if it were sold by weight you would be buying less of a wet product than a dry one. A kilo of rock weighs the same as a kilo of feathers but the later would be much larger. Selling variable products by volume is in no way an exact science but on balance it’s the best way to ensure you receive a reasonably consistent measure of product for your money. Volumes stated are always for loose product measured out prior to packaging or shipping. Many conventional products are measured out and then vacuum packed to reduce their bulk for shipping purposes. Before use these product would need to be shaken out and mixed to restore the original volume. Kaizen Bonsai do not vacuum pack products but allowance must be made for consolidation and very minor degradation due to abrasive action that occurs during shipping. 1 litre is a measure of volume and indicates a cube of 10cm x 10cm x 10cm making a volume of 1 litre or 1000ml. In old money that's a cube of about 4” square. Kaizen Bonsai product volumes are guaranteed at time of production and packaging to be within tolerances of -0/+5% but may vary post shipping.

Many products we sell are packaged right here in house. However where we sell products produced by other suppliers, for instance Akadama, any measure of weight or volume that is given to us or stated by the manufacturer or importer and is beyond our control. Any measure of weight or volume is passed on in good faith by us. Our soil products are normally packaged in polythene bags and these should be handled in a appropriate manner and disposed of responsibly as per local prevailing regulations.

Handling and use of our soil or growing media products should follow common sense guidelines. Many soil products are heavy, bear that in mind when handling. If you are sensitive to acids, alkali, dust, plant extracts, tree resins, naturally occurring bacteria or moulds you will need to take appropriate precautions. Prolonged skin contact with any soil or growing media can present issues for those with sensitive skin and should be avoided. Where a product produces and dust or fine airborne particulates during use this should be avoided using appropriate safety equipment.
Where we make recommendations as to a products use this is given in good faith and based upon our own experiences of using the product on our UK based nursery. We take no responsibility for the use of our product where circumstances are outside of our control and it’s your own responsibility to ensure the product is suitable for your intended use.

Notes for general guidance only. Produced in good faith to enable our customers to understand what they are buying.
© Kaizen Bonsai Ltd 07/2018

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