Lightweight aggregates

Is anyone aware of research or testing of commercially available lightweight aggregates as a component of bonsai mix?

Lafarge offers Litex - described as “a sterile, inorganic medium that provides a reservoir for water. Litex can also be used as a ground cover or in soil-less mixes. Loose bulk densities range from 880-1200 Kg/m3. Product sizes range from ½-inch coarse to sands.”

Peter Chan seems very satisfied with the fine feeder roots produced by a UK product called Lytag shown in a 26 Jan 2020 YouTube video (Repotting a Privet Bonsai).

From my perspective LaFarge indicates that Lytex is a recycled expanded plastic product. Agricultural use of plastic products has revealed difficulty with phytotoxicity in many cases. I would want to see some research on its safety for use with plants before considering it as a bonsai component.

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Ahhh - thank you Frank - I missed that. I noted that one of their aggregates listed plastic as a component but I assumed the inorganic in Litex might be mineral.

I looked at Lytag, but it isn’t that easy to get hold of. I’m in the UK too.

Very similar and certainly more horticultural and easier to get are the various expanded clay products you will find in a hydroponics shop. I’m using one called “Hydrocorn”, which is very varied in shape and sometimes size, which I like. Usually in a very large bag.

A more evenly sized product available in small quantities is “Odla” from Ikea, £3.50 for 5L.

Both of these products are large in grain size compared to regular bonsai soil. I use them in combination with pumice (bonsai) or perlite (hydroponics) as a top dressing, I can’t comment on how effective any of these are yet though.

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First, I have used styrofoam packing peanuts in my large pots of ornamental plants for many years. It works like gravel and makes big pots manageable. Watch out for the organic environmentally friendly packing material that dissolves when wet.

Here in the SE USA I use:
it is an expanded shale developed for lightweight aggregate. It is also sold bagged as Permatill and Vole Guard (large size 3/16 to 1/2"). Physically it holds water very similar to lava rock. I have not looked into the chemical composition comparison. As I live 20 miles from the mine and plant, I buy 5 yards bulk of the construction size CA 9 which is about 1/16 - 1/4".

Thanks David.
That looks like an interesting product. I imagine bulk buying is a real deal!
I wonder why it is not available in the west.
How does it compare to lava rock in terms of weight?

The rock used to make Stalite brand lightweight aggregate is mined here in the Carolinas. I expect shipping cost makes this a very distance sensitive product. The cost of a bag of Double red line Aksdama at a DIY store in Japan was $4.50 USD a few years ago, when the same bag in the USA was $40.00. Bulk is cheap $100/ ton approx 1.5 cu yd. Pumice is also cheap by the truckload from the mines and near where it is mined however the 1500 mile truck ride is costly.

Lava rock density is around 90 lb/cu ft

Stalite density: 3/8" is 47 lbs/cu ft

both numbers vary

Stalite seems much stronger than LR. I use Stalite in place of almost all my mixes that call for LR or course sand including for nursery stock mix.

BTW I was using the larger Stalite Permatill (also bought in bulk locally)until I learned that the North Carolina Arboretum in Asheville was using the CA9 in the soil mix for their bonsai collection.

Thanks for this information David.
The earth offers an amazing variety of materials and components.