Preferred for hydroponics and high porosity soil mixes. Horticultural vermiculite is permanent, clean, odorless, non-toxic, sterile and pH neutral. It will not deteriorate, turn moldy or rot. Mixed with soil, peat, composted pine bark, fertilizers, pesticides and herbicides and promotes faster root growth and quick anchorage to young roots. Vermiculite granules attract and hold ammonium, potassium, calcium and magnesium needed for the growing plants. Vermiculite/peat mixture provides excellent aeration and retention of plant food and moisture.