It is harvested, dried and finally heated to remove organisms and parasites. It is then pulverized in several sizes.
It is mainly used in the bonsai field, often as a component of the soil, or it can be combined with other elements such as sand, larch, peat, or gravel.
It has some features that make it particularly interesting:
- Provides the right balance of water, air and nutrients;
- Contains enormous amounts of minerals due to its volcanic origin;
- Holds the water for a long time without leaving the roots too moist;
- It is a good help to understand when watering the plant, since losing its moisture its dark reddish-yellow color;
- Has a neutral pH (pH 6.5-6.9), so it is not usually necessary to change the acidity of the water.