Vermiculite is a type of potting medium soil used on its own or combined into a soil mixture. The properties of vermiculite provide soil moisture retention and porous qualities it might not have otherwise. Vermiculite is ideal for starting flowers from seed and storing bulbs.
Vermiculite is a mica, or silica material, which is made of fine fibers cured under heat. Pieces of vermiculite have several thousand paper-thin layers, making it excellent for absorbing water.
Use in Soil
Vermiculite does not have nutritional value for soil, but can change its qualities. The kernels of vermiculite hold several times their weight in water, making sandy soils that cannot hold water suitable for flowers which require a fair amount of water for growth. Vermiculite also changes the soil composition, making it easier for flowers to expand their roots through thick soils, such as clay.
Propagation of flowers is regular practice for cross breeding and cloning ideal flowers. Vermiculite is often used to root cuttings from flowers to grow into new plants. Its moisture absorption qualities provide ample moisture for the rooting solution cuttings are dipped in. Cuttings put into a small pot filled with vermiculite and water require little watering, making it possible to leave the cuttings alone during the delicate rooting phase.
Flower Seed Germination
Vermiculite can be used alone or with a small amount of potting soil or peat to germinate flower seeds before they are planted outside. This is common practice for gardeners living in areas where cold springs make it difficult to plant certain varieties outside early enough for a successful summer. Seeds cal also be germinated inside using vermiculite and a tablespoonful of soluble fertilizer, then transplanted outside once the weather breaks.
Vermiculite is used to store flower bulbs, preventing mildew accumulation, and keeps moisture levels in the bulb consistent during the storing period. Vermiculite takes up water from the environment, leaving the moisture inside the bulb alone. Container bulbs covered in vermiculite and moistened will keep for several months. Once used for this purpose, the vermiculite should be disposed of.