October 2009: Tescos have rebranded their catlitter and the product I use is now called 'Low Dust Lightweight Catlitter' and comes in yellow/pink packaging

November 2009: Cyprus/Terramol from Damolin

Akadama, Turface and Seramis are among the most popular high quality (inorganic) soil components available in which to plant your bonsai. Unfortunately, they can be difficult to source and are expensive particularly if you have many large trees to repot, have to buy by mail order or just require a small quantity for a small number of trees.

These soil components are all (basically) clay granules that have been fired/heated to create small pellets or granules that are water retentive, extremely well draining and are stable, that is they will not breakdown over the course of the year.

Some cat litter products are exactly this; fired clay granules. Originally, a knowledgeable fellow enthusiast who has been using it as a bonsai soil for the past decade, introduced me to using clay granules intended as cat litter a number of years ago. I have been planting all of my bonsai in this particular brand of catlitter for a number of years now and it has proved to be an excellent material that I would now comfortably recommend as being superior to Akadama and Seramis.

As time has gone on since first writing this article around 2004, I have since heard from many enthusiasts who have switched to Tescos Low Dust Lightweight and a number of other similar (diatomaceous earth/diatomite) products with great success.

Old white packaging for Tescos Cat litter on the left, new yellow packaging on the right

Very easily available in the UK, I use an own-brand product available from 'Tescos' called 'Low Dust Lightweight Catlitter' (previously known as 'Premium Lightweight'). There are other brands that make suitable bonsai soil (see the updates at the foot of the page) but this is the only one I have direct experience of and can therefore personally recommend.
I use this product for my all of my bonsai, with cuttings and air layers and even newly collected yamadori (collected trees) all to good effect.

At a cost of just around £5.00 for 16 litres, easy availability (as there seems to be a Tescos Superstore wherever you turn in the UK), and an absolutely ideal medium for growing healthy bonsai, if you are living in the UK, I couldn't recommend any other soil for bonsai at the moment.

'Low Dust Lightweight' can be used on its own (100% pure) for all tree species, or, for a slightly drier soil for coniferous species, up to 30% grit can be added.

If you require a slightly more water retentive mix for bonsai in small pots (mame) or to lengthen the amount of time between each watering, the addition of approximately 10%-20% chopped bark is useful.

Appearance of 'Low Dust Lightweight' Cat Litter

Areas outside the UK

To find suitable alternative brands outside the UK, you must be prepared to try a number of products until you find the correct material. This can be difficult, as very few makers of cat litter will display the ingredients on the outside of the packaging!
Avoid all products containing paper, wood chippings or Fullers Earth as these will swell when wet. Also avoid the cheapest clay products as these are more likely to contain unfired clay granules.
Unfired clay granules swell and clump together when wet and crumble when dry. As the granules break down and congeal they will do great damage to the roots of your tree, causing the roots to rot and the tree to die. Watering properly will be virtually impossible. It is of maximum importance that any cat litter clay granules you use keep their structure indefinitely.
To test a new product for its ability to retain its structure, first soak some of it in water for 24/48 hours and check that the granules do not break down. Then try putting the wet granules into the freezer for a few days and see if they retain their structure after thawing out. Reject any products that break apart. To illustrate how strong the 'Low Dust Lightweight' granules I am using are, they are impossible to break between the finger and thumb, even when wet or frozen.
Finally if you have any doubts, use the granules for cuttings and seedlings at first; these will react to anything 'bad' in the soil quickly and their loss can be taken much more easily than if you lose a bonsai.

Perfumed Cat Litter

Many Cat Litters are perfumed; the perfumes themselves should create no problems as they are quickly dissipated after contact with water. If in any doubt, watering the mixture a week before use will release most, if not all of any residual perfumes.
Some products can also contain baking soda, this is used by the manufacturers to neutralize odours. Baking Soda is far more 'stable' in the soil, that is, it will remain in the soil for longer than any perfume will. However, all of the research I have been able to obtain indicates that baking soda has actually been long used as a fungicide against mildew in roses and other members of the rosaceae family (Hawthorns, Crab Apples etc).
According to Cornell University research, the only plant damage associated with baking soda/Sodium Bicarbonate in tests, resulted from some foliage burn when the leaves were sprayed with a highly concentrated dose of Baking Soda.
The Cornell testing also established that Sodium Bicarbonate does not increase the levels of Sodium in plant tissues, soil or run off water.
Sodium Bicarbonate is an alkaline substance but in cat litter it appears to be in too small a quantity to effect the pH of the soil. My understanding is also that though Sodium Bicarbonate will neutralise acids it will not increase alkalinity.
However, I do have to recommend that if using any brand of catlitter for the first time, check the pH of the soil. In the case of Tescos 'Premium Lightweight' cat litter, all tests I have made have shown a neutral pH of 7.

Feeding Trees Growing In Catlitter (and all other inorganic soils)

If there is one thing that seems to worry enthusiasts about switching to an inorganic soil is the lack of 'proper' organic and a 'lack of nutrients'.

Firstly, I and many (most) experienced enthusiasts have switched to largely inorganic soils (such as catlitter, baked clay, akadama, turface etc etc) entirely and have been using these products for many years (I started using catlitter only 3 years ago but have been using inorganics for the past decade or more). The reason for switching to inorganic's is purely for the increased health, vigour and strength that it provides a bonsai (or any plant for that matter). Be confident that switching to inorganic soils is widely considered 'best practice'.

Bonsai grown in an inorganic soil do not need any special fertilising regime or special ingredients to keep them healthy.

There are of course some differences between compost-based organic mixes and inorganic mixes. Inorganic soils contain little or no nutrients, however, compost/peat based organic soils just as equally only provide very limited nutrients to a bonsai and these are quickly depleted within a bonsai pot.

Organics are able to retain more nutrients better than inorganic's (after feeding) but this is not necessarily a good thing. Trees growing in inorganic's need (but can also take without any danger of root burn) more fertiliser than those growing in an organic soil. Many enthusiasts see this as being advantageous though as it allows the enthusiast to feed their bonsai heavily to encourage better growth, health and faster development.

That an organic bonsai soil can hold nutrients for a little longer than an inorganic bonsai soil is hardly advantageous as bonsai growing in organic soils still need to be fed regularly!

With my inorganic soil mix, I am able to feed heavily and use (as do many) a slow release fertiliser and a fortnightly full strength balanced plant fertiliser simultaneously throughout the growing season.

Finding Other Sources Since writing this article a number of years ago, I have received several e-mails from bonsai enthusiasts outside the UK trying to find a suitable cat-litter/fired clay product to use as bonsai soil. Fortunately I have received some very useful information from bonsai enthusiast Tim Riley who has done some research into 'Tescos Low Dust Lightweight' and has discovered other possible sources for those outside of the UK. My thanks go to Tim for making this information available. Tescos Low Dust Lightweight cat litter is a 'Moler Clay' and originates from Denmark, exported by a Scandinavian company - Damolin. Moler Clay is a type of Diatomaceous Earth or 'Diatomite'. "Diatomaceous earth consists of fossilized remains of diatoms, a type of hard-shelled algae. It is used as a filtration aid, as a mild abrasive, as a mechanical insecticide, as an absorbent for liquids, as cat litter, as an activator in blood clotting studies, and as a component of dynamite. As it is also heat-resistant, it can be used as a thermal insulator." "Freshwater diatomite (Diatomaceous Earth) can be used as a growing medium in hydroponics gardens. It is also used as a growing medium in potted plants, particularly as bonsai soil. Bonsai enthusiasts use it as a soil additive or pot a bonsai tree in 100% Diatomaceous earth. Like perlite, vermiculite, and expanded clay, it retains water and nutrients while draining fast, allowing high oxygen circulation within the growing medium." "Its absorbent qualities make it useful for spill clean-up and the U.S. Center for Disease Control recommends it to clean up toxic liquid spills.” “More recently, it has been employed as a primary ingredient in a type of cat litter. The type of silica used in cat litter comes from freshwater sources and does not pose a significant health risk to pets or humans." (Source: http://en.wikipedia.org/wiki/Diatomaceous_earth) So essentially, if you are unable to obtain 'Tescos Low Dust Lightweight' cat-litter (moler-clay/ Diatomaceous Earth/diatomite) what other product names is it sold as? In the UK there is a product called Sophisticat Pink cat litter that is sold at 'Petsmart' and 'Pets at Home' and it is exactly the same clay granules as those sold as 'Tescos Low Dust Lightweight'. (Interestingly, there are a few references online to experienced UK bonsai enthusiasts that have been using Sophisticat Pink cat litter to good effect for many years). Don Smith aka 'Stymie' from the South Yorkshire Bonsai Society has e-mailed to let me know he has been using cat litter to good effect for 4 years now and has found that Sophisticat Pink which has varied size grains (unlike the standard round pellet of Tescos Low Dust Lightweight), the majority of which are larger than those now found in Tescos product. Sophisticat Pink is imported into the UK by a company called Steetleys who are bagging it up under a number of different product names. It is very possible that there are other UK chain stores other than Tescos that are selling the same product as Sophisticat Pink and Tescos Low Dust Lightweight under different 'own brand' packaging. So Steetleys are importing from a Scandinavian company Damolin and bagging it up under different names. On the Damolin site it appears that French & German subsidiaries distribute Damolin cat litter for the rest of Europe. A Google search for Diatomaceous Earth and/or diatomite (as it is also known) throws up many different sources throughout the world. (For instance) There are references to http://www.moltan.com/ultrasorb.html (US), http://www.diatomiteusa.com/ (US) and http://mmsd1.mms.nrcan.gc.ca/minerals/Min/diatomite.htm (Canada) all of which seem to offer suitable equivalents to the product I have been using (Low Dust Lightweight). So I would recommend searching online for Diatomaceous Earth and/or diatomite products in your country. These will be sold as cat litters, oil-absorbents, soil conditioners or as hydroponics products. You may be very surprised to find that a cheap, easily sourced and high quality bonsai soil can be bought in your local pet shop or supermarket! Please ensure that you check the suitability of any products that you obtain using the method described elsewhere in this article and try growing some seedlings or young plants to test your new 'soil' before using it for a prized tree! If you discover that the product is suitable as a bonsai soil; please tell me so I can list it within this article for the benefit of other enthusiasts! Further Sources/Suitable Products: Since my recent update on this article, I have received a number of e-mails from readers that may well be of great interest to other enthusiasts; United States Bryan Russ has been practicing bonsai for 3 years now and says he has tried many different types of American-brand catlitter's with no luck. However, Bryan says after a lot of research into diatomaceous earth "it lead me to contact a mineral mine in Nevada and I found out that NAPA auto parts sells their freshwater diatomaceous earth as an oil absorber. It is 100% Diatomaceous earth and is sold under the NAPA store brand name and comes in a 25 lb bags. it is around 6$ per bag and works awesome!! Make sure to get the 25 lb bag and double check the back of the bag and make sure it says diatomaceous earth in the small print. NAPA Auto Parts stores are all over the US and anyone should be relatively close to one." Bryan goes on to say "the murky water that is left after one initially rinses the diatomaceous earth for the first time is actually a mechanical pesticide. I spray the liquid on my trees if they get aphids and the aphids are gone the next day. The sharp microscopic edges of the Diatoms cut through the exoskeleton of the insect causing them to dry out and die." Diatomaceous Earth from Napa Auto Parts. Images courtesy of E McCracken Sweden, Denmark, Norway and Finland (and very possibly other parts of Europe) Magnus from Sweden has mailed to tell me "I have been using Danish moler cat litter since 2005. It is the perfect soil ingredient, I can buy it at the local supermarket and it is very cheap. It is superior to akadama in every way, since I am a soil scientist I have data to back up that statement if needed. Nowadays it is used by many bonsai growers in Sweden. In Sweden there are two different brands, Coop X-tra and Eldorado, the former has a particle size of 1-3 mm and the latter 3-6 mm. Neither of them is perfumed. The Coop x-tra is also sold in Denmark, Norway and Finland. If you want to know brand names in other countries I suggest you e-mail Damolin and ask, I have been in contact with them and they were very helpful." Netherlands Bonsai enthusiast Rik Moonen has e-mailed to say "I have been trying to trace a usable cat litter or other source of diatomaceous earth in the Netherlands, but have not yet been successful. I did however find another easily available product which I think is superior to akadama. It is an exclay (LECA, as for hydroponics, in Dutch: hydrokorrels) product." "It is sold as a water side substrate at a price of EUR 9,45 for 15L at Sawin under the brand name Velda. (http://www.velda.com/L01p4000.php?id=100003 for Dutch and http://www.velda.com/L02p4000.php?id=100313 for English). Next to the grain size another advantage over standard LECA is that because of its use in ponds it has been thoroughly washed to remove any harmful byproducts. According to the producer it can retain up to 40% water. When dry it is very lightweight. The grains are much harder that akadama and will not disintegrate." France and Spain Christophe Appriou says "I have been buying cat litter since 2005 with success. I buy it at a local supermarket (named MUTAN ) less than 1 Euro for 7 litres." Christophe is in France but judging by the packaging in the image he sent me (above), it should also be available in Spain. Switzerland, France and Germany Jasper Stil lives on the Switzerland/France border and has discovered this 'Diatomite' Cat Litter from his local 'Migros' supermarket (in Switzerland). Jasper originally contacted me with regard to finding a suitable cat litter he could obtain locally rather than having to repeatedly import expensive bags of akadama from France. Jasper tells me "it looks more or less the same as akadama when dry, but is so much more enjoyable because it is less uniformly colored when wet". Jasper also confirms that while he can crush brand new Akadama between his fingers, this material is very strong and does not break down at all . The cost of this particular brand of cat litter is just 3,90 swiss francs, around £1.75 for 15 litres of bonsai soil! Interestingly, the labelling of this product actually recommends this cat litter for pot plants. 'Melanie' at the ParlonsBonsai.com forum tested some of this cat litter and found that "That the pellets are calcined diatomite. Resisting several days soaking in water, with no degradation, pH 7 (test with litmus test), no presence of limestone (negative chloridrique acid)" and Jasper confirmed that the litter did not degrade after freezing and thawing. Brazil and Argentina Pedro Bessa in Brazil contacted me and said: "Your article about cat litter as bonsai soil intrigued me. You see, akadama and other options are unavailable or very expensive in Brazil. So I was searching for another soil. After reading your article, I searched for cat litter to use and the first one proved awful. After the first drop of water, it aggregated and formed a stone-like ball. Where were the 'good' ones? After a while, I found two brands that do not aggregate the granules. I went to the producers suppliers (it´s the same one...) website and found it very interesting". http://www.solminerales.com.ar/catliter/caract.htm "So I have now had success with all of them! The brands I am using are Absorsol and Tidy Cat (the later one from Purina) Both are in this picture: http://www.solminerales.com.ar/catliter/presentac1.htm" 'Terramol'/Holland and possibly many other European countries Jasper Stil has contacted me with regards the Danish company Damolin, who are now advertising a Diatomaceous Earth or 'Diatomite' product called 'Terramol' as being a medium specifically for growing plants (bonsai). So far Jasper has only located Terramol as being sold at a bonsai nursery in Holland (BonsaiStudio.nl) however it is highly likely that Terramol will also be sold in many countries across Europe. Australia Tim in Brisbane tells me: Diatomite is mined in Kingaroy near Brisbane by a company named Maidenwell. They bag pure diatomite in various sizes and in raw form. It has been fired to 650° and cleaned for use as a growing medium. The majority of colour is white, tan, browns and the odd red. However, finding it is quite hard! Contact Maidenwell through their website. A 40 litre bag costs Aus$20. Maidenwell even contacted a local nursery who then contacted me the next day. SEPTONE Dry-up is an industrial product labeled as diatomite. AVOID THIS. It is not cleaned and contains 60% clay! United States Though not diatomite exactly, another very similar product that I have heard being used in the past in the US is 'Dri-Zit' or 'Hi-Dri'. Cory J. has e-mailed to say he has 'found a very good akadama substitute in the US; it's called Hi-dri, and you can get a 40 pound bag at Carquest Auto Parts for about 8 bucks. It's the same thing as Dri-zit, which they unfortunately don't make any more.' A quick search on Google shows that a large number of enthusiasts have found this product to be a very viable soil for bonsai with the same qualities as the cat litter I am using. For further information and images please visit here   Luxembourg, Germany and possibly Belgium Chris Ray tells me that after reading this article "I went hunting in Luxembourg (for Diatomite),after one disastrous bag, I found "Thomas Katzenstreu" in 30 Litre yellow bags. I have had a sample submerged now for 3 months with no sign of breakdown and potted some sacrificial plants in the stuff which seem to be doing fine. It costs around €8 (8 euro) for 30 litres. "Thomas Katzenstreu" should be available in Luxembourg, Germany and probably Belgium. Chris has provided me with this link to an article by someone who has been successfully using this product for a number of years. Thomas Katzenstreu Germany Oliver Schneider contacted the German branch of Damolin while in search of a Diatomite source in Germany and obtained the following information; The first is that the 'local' fire department use a version of Diatomite as liquid absorbant and it is sold under the name of 'Absordan' (or 'Absodan', he found both brand names). The second is an online shop where the 'plant' version (Damolin's name for this is 'Terramol') is sold under the name 'Kieselgur' which is the direct German translation of 'diatomaceous earth' in 3 different sizes (0.5-1mm, 1-3mm, 3-6mm) with a pH of about 5.5 and 30kg about 30€. Latvia and Baltic States Juris Zvaigzne from Latvia has written to me telling me that he has found a cat litter by Damolin, sold by the product name 'Catfield'. The packaging even shows that it can be used for plants. There is also an alternative called Fibo ExClay. For a complete list of countries they deliver to visit http://www.maxit-group.com/1598/ Juris has also found this product by Damolin that is also suitable for bonsai soil called 'Amigo'. This can bought in most stores in Latvia. Guatemala Andres Avalos has e-mailed to tell me about a product known as 'Cats Pride'. "CatsPride" (www.catspride.com), is imported from Oil-Dri Corp of America... and available at a store called "NOVEX" in Guatemala. Andres is a bio-chemist and has tested the product and found it to have a pH of 7.4 and to hold its shape after soaking with water. He also believes that this product maybe available in Costa Rica. Holland and Europe Jerry Norbury has written to tell me about the Purina “Tidy Cat” range that is sold in Holland under the title “Purina Tom Poes – Foetsie Ba”. It’s Danish Clay and looks very similar to the Migros product both dry and wet. Jerry tells me he has tested it by freezing it and thawing it every day for 2 weeks. It’s been down to -10C outside and then back inside into boiling water and it’s held together perfectly. An online search reveals this product to be available in all major Dutch pet stores (and by mail order) but Jerry hasn't seen it available in any supermarkets yet. Belgium Jean-Paul contacted Damolin, in Denmark, as he was unable to locate any cat-litter in Brussels where he lives. With their help he was able to find their 20l bags of Tom Poes/Foetsie Ba in a petshop which is part of a big chain of shops called”Tom&Co”, that are present in most of Belgium. Jean-Paul tried the product and feel quite happy with it: it’s made of coarse, hard grains of fired clay and is not dusty. UK David Oates tells me: "I recently read your article on cat litter as bonsai soil/growing medium. Idon't live that close to a tesco but I do live quite close to a Wilkinsons store which does a calcined clay cat litter." David has since e-mailed me to say he has put the cat litter through 5cycles of soak, freeze and thaw with no clumping or obvious signs of degradation. Canada/United States Jose Leon in Edmonton, Alberta, Canada has written to tell me about Schultz Aquatic Soil Jose says that "I have exposed the soil to a complete 5 cycles of freezing and defrost, kept it submerged in water for a whole week and the soil does not break down." Cyprus/Terramol from Damolin Dr Stavros Eleftheriou tells me, "During the last year, I have searched all the supermarkets and pet shops in Cyprus and I could NOT find moler clay granules sold as cat litter". This is why I am importing now directly from DAMOLIN. The product is called TERRAMOL, with 3-6mm granule size, and is available in 20Kg bags.