What is Lecca (or Leca) for?

Found this 1.5L Lecca soil sold cheaply in local nursery but could this be Leca instead due to typo but anyway may question is that can use this to replace Pumice or Lave as the size meet my requirement of 2~4mm.

Kindly advice.

Yes it is Leca. It works well as a component in Bonsai Soil and has the added advantage of lasting a very long time. One of the draw backs is the common round shape and also the size can be an issue for most applications. Typically larger than desireable.
If the product available to you is irregular in shape and smaller sizes than that is beneficial. The cost appears higher than appropriately sized and packed pumice and lava. I purchase screened horticultural pumice for $6.50 per 15 litre bag. That puts the comparable cost at .65 cents for 1 1/2 litre bag as opposed to $2.50. The label indicates GST so i assume the pricing is canadian as is mine.
The best use, i have found for Leca is as a reusable drainage layer. Due to its size it might have a use for developing exposed root styles as well. Perhaps others can offer examples of how they have used the product.

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The Leca is imported material and cost ~U$2 after conversion. i bought a small packet with irregular shape, size around 2~4mm, see pic attach for info.

Thanks for sharing - I hadn’t seen Leca before.

A similar product is widely available in the US Midwest as the trade name Haydite, where it is rotary kiln fired shale. It tends to have more irregular shapes than the pictures I see of Leca. Usually owing to the fact that Leca and the round hydroponic aggregates are fired clay. As such, the density is probably different between geologic deposits (along with some color variability).

Regarding Haydite, I would characterize it as a cheaper inferior substitute for scoria (lava). From published literature, it is generally less porous than scoria and the porosity can be less interconnected. This could make it harder to completely saturate. For positives, it can be less dense than scoria which means less added weight to the container. It also tends to be available in bulk, in areas where scoria is not available. As such, I used it as an inorganic component with pine bark in a nursery type mix for growing out stock. I stopped using it when I moved to an area where pumice is available in bulk.

Colin Lewis wrote a negative opinion of it for bonsai: https://www.colinlewisbonsai.com/Reading/soils2.html

I’m not that negative on it, but would caution that the physical properties could vary between fired clay, fired shale, and different geologic deposits. Of course this also true to a lesser degree with scoria.

Just my 2 cents!

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It is sold here in Brazil in small sifted particles (smaller than this Lecca from the Op) and is used by many bonsai growers. Some people use it for pines.
:slight_smile: