Horticultural Vermiculite

Light, sterile and easy to work into a mix, horticultural vermiculite helps seed flats and potting soil hold water a little longer. Stir it into your own blend, sprinkle it over seeds or use it as the growing medium in hydroponics. It's a small addition that pays off across a lot of seed starting.

Vermiculite is mica that's been super-heated until it expands, much like an accordion. Growers use it in seed flats to protect seeds from air currents and to insulate them, which helps germination happen at a steady temperature. Its neutral pH means it won't push a mix out of balance.

Highlights

• Helps mixes hold more water
• Shelters seeds from air currents
• Lightweight, sterile mineral
• Neutral pH
• Works in potting mix, hydroponic media or as a seed cover

Why use vermiculite

Mixes that dry out fast need something to hold water between waterings. Vermiculite does that job and keeps the mix light and easy to work. A light, even surface also lets a seed flat stay moist without packing the seeds under soil.

Vermiculite suits seed starters, container gardeners and anybody building their own mix. Pick it when a blend runs dry too fast. Perlite is the better choice when drainage is the bigger problem, because perlite drains where vermiculite holds moisture. Knowing which one a mix needs is most of the decision.

At a glance

How to use it

Stir vermiculite into a potting blend in an even layer, so it isn't clumped in one spot. For seed starting, moisten the mix, sow the seed and sift a thin layer of vermiculite over the top. Check the seed packet for how deep to sow, since some seeds need light and should be barely covered. For hydroponics, use it as the growing medium and keep it moist between feedings.

Good to know

• Wet it lightly before mixing to keep the dust down.
• Work outdoors or wear a dust mask when you open it, since the dust is fine.
• Pair it with peat for a seed mix that holds moisture.
• Keep it dry in storage so it's ready the next time the seed flats come out.

About Fertilome

Fertilome has been giving green thumbs a hand since 1968. Its line includes plant foods, weed killers and natural options for lawns and gardens, and it keeps adding products for both.

Get it on the shelf before seed-starting season, so the flats are ready when the weather turns.