What Is Vermiculite Seed Starter?


Many plants are can be started or bought in different stages of growth. An already established plant can be bought at local garden centers, plants can be started from bulbs or other types of self contained systems like tubers and rhizomes. Finally, plants can be started from seeds. Plants started from seeds have different requirements. One is a soil mixture that is best for seed germination. Vermiculite is often used for this purpose.

Industrial Vermiculite

In its raw form vermiculite is a hydrated magnesium aluminum silicate. It is a member of the phyllosilicate group of minerals. It is mined primarily out of South Africa, China, Brazil, Zimbabwe and the United States. Vermiculite is manufactured at high temperatures and is sterile, thus making fertilizer and pesticides work longer than they otherwise would without. It also works well as packing material for bulbs and tubers.

Gardening Vermiculite

For gardening purposes, the vermiculite has been exfoliated or expanded in form. This form is lightweight, highly absorbent, and can be mixed with other materials to produce a growing media for plants. Vermiculite can increase exposure to air while maintaining moisture and the nutrients necessary to feed roots, cuttings or seeds for quicker germination. It can also hold and make available to the growing plant ammonium, potassium, calcium and magnesium.

Characteristics of Vermiculite

Vermiculite is enduring, clean, odor free and non-toxic. The pH is basically neutral. When mixed with peat or organic compost, it helps promote faster root growth and helps the young roots attach and develop quicker. Vermiculite is light and easy to handle.

Seed Germination

Different flower seeds require different seed preparation before planting. Once they are ready for the planting, the mixture used to sow the seeds is important to growth and development. Vermiculite can be used alone or as mixture with soil or peat. There is less watering necessary, plus there will be more seeds germinating and growing faster. The vermiculite mixture does not require fertilizing until the time of transplanting the seed into a pot or into the garden. Vermiculite can also be used alone as the sole mixture for the seed. In this instance, seedlings should be given a light fertilizing after the first true leaves appear.


If the plant has out grown its pot or is being transferred outdoors, it can be pulled easily with all the roots intact from vermiculite. If some of the vermiculite sticks to the roots, do not it shake it off but leave it still attached to the plant. The roots left behind in transplanting from seeds started in vermiculite are off to a much better start than other plants. Again, vermiculite is the best mixture to start re-rooted plants as well.

Keywords: Vermiculite, Seeding Vermiculite, About Vermiculite

About this Author

Sheri Engstrom has been writing for 15 years. She is currently a gardening writer for Demand Studios. Engstrom completed the master gardener program at the University of Minnesota Extension service. She is published in their book "The Best Plants for 30 Tough Sites." She is also the online education examiner Minneapolis for Examiner.com.