I have got a huge lot of LECA pebbles recently from a friend who has lost his interest in hydroponics.

But I have already bought enough of large sized lava rock to be used as drainage layers in pots for my future gardening. So I wonder if I can crush those LECA pebbles into small pieces to be mixed with soil for planting succulents?

Thank you for any advice.

1 Answer 1


Short answer: yes you can.

Long answer: LECA pebbles comprise of many small bubbles (which are formed via the extreme heating of the clay). Hence, when you crush them, you get a similarly porous surface. From personal experience, I have crushed LECA pebbles and used them to lighten soil for saintpaulia and succulents. There are a few practical considerations to take into account when doing this, though.

  1. The crushed pieces will be sharp; the LECA pebbles are nice and round due to being formed in a rotary kiln. Thus, you might want to consider potential root damage due to large sharp pieces (as opposed to other sharp substrates such as sand, which have smaller grains).
  2. Consistency: again from personal experience, the crushed LECA pebbles have many different sizes and you do produce a nontrivial amount of dust. Do you want to include the dust/sandy part? Do you only want the larger pieces? You might want to have a sieve ready with the required diameter of a piece. Also, if you have dust allergies, do consider wearing a mask in the process. Personally, I keep some of the dust, and try to get the biggest piece to be less than 5mm.
  3. Potential effects on soil. You might want to use this to increase soil aeration. There might be other effects of using LECA which might not be as beneficial to more sensitive plants (though perhaps succulents do not fall in this category!). According to Miss Orchid Girl (and other sites), LECA alters the pH of the medium. It is possible that the smaller pieces might have a similar effect.

Hope this helps! Personally, I have found that using crushed LECA is a very nice way of customising soil to suit different plant needs, and hope it turns out useful to you, as well!

  • 1
    Thank you Simon. Usually I mix lava rock sized less than 5mm with peat and soil to plant succulents (majorly in Family Crassulaceae). Lava rock is much harder and sharper than crushed LECA. So I think the potential root damage caused by crushed LECA might be bearable for succulents as well.
    – daier
    Dec 21, 2021 at 18:53

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