Horticultural vermiculite can be used as a soil conditioner. Because horticultural expanded vermiculite has good cation exchange and adsorption, it can improve soil structure, store water and preserve moisture, improve soil permeability and moisture content, and turn acidic soil into neutral soil; Vermiculite can also act as a buffer, hinder the rapid change of pH value, make the fertilizer slowly release in the crop growth medium, and allow the slightly excessive use of fertilizer without harm to plants; Vermiculite can also provide crops with K, Mg, CA, Fe and trace elements such as Mn, Cu and Zn. Horticultural vermiculite plays multiple roles in preserving fertilizer, water, water storage, air permeability and mineral fertilizer.
The unit weight of horticultural vermiculite is 130-180 kg / m3, which is neutral to alkaline (ph7-9). Each cubic meter of vermiculite can absorb 500-650 liters of water. Horticultural vermiculite is one of the main materials for planting media, and can be mixed with peat, perlite, etc.
There are two common specifications of horticultural vermiculite: 1-3mm horticultural vermiculite for seedling cultivation and 2-4mm horticultural vermiculite for flower planting. 3-6mm and 4-8mm are also available.
Common models
| Particle (mm) or (mesh) | Volumetric weight (kg / m3) | water absorption(%) |
| 4-8mm | 80-150 | >250 |
| 3-6mm | 80-150 | >250 |
| 2-4mm | 80-150 | >250 |
| 1-3mm | 80-180 | >250 |
| Particle (mm) or (mesh) | Volumetric weight (kg / m3) | water absorption(%) |
| 4-8mm | 80-150 | >250 |
| 3-6mm | 80-150 | >250 |
| 2-4mm | 80-150 | >250 |
| 1-3mm | 80-180 | >250 |