Vermiculite

Gardening with Vermiculite. Vermiculite for Plants.

Before you start to plant your seedlings in your garden, you want to take advantage of minerals and other healthy additives for both your plant and garden. One of the most common options is vermiculite, and it is used in soil to provide a healthy environment for the growing plants.

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What is vermiculite?

Available in most garden sections, vermiculite is a substrate that traps moisture in the soil where you are growing your seedlings to enhance their survival.

Vermiculite resembles mica, and it’s a hydrated laminar mineral.  The minerals are exposed to extreme heat, which causes them to expand.

Vermiculite that is used for plants resembles small accordion-like pellets.  It’s extremely lightweight, which can help improve seed starting soil mixes.

If you purchase vermiculite, it will not rot or break down before you can use it. It is not toxic to your health, and it is mold-resistant, allowing it to be stored and kept for future planting.

Vermiculite allows plants to maintain their moisture for longer periods of time, preventing the need for excessive watering during periods when they could lose their moisture and their ability to thrive.

Vermiculite has a neutral pH of 7.0.  It can react with some substances in the soil and can become slightly alkaline.

What is vermiculite used for?

The purpose of using vermiculite is to enhance the hydration of your plants. With vermiculite, you are able to water your plants less in hot climates and through the summer months when it is more difficult to get out there.

Vermiculite helps to make the soil lighter, less compact, and hold more water.

Since seedlings are the most vulnerable before being planted, they do not have the ability to maintain the moisture they need sometimes. In soil that is full of clay or sand, being able to maintain that hydration may be much harder for the seedlings.

With vermiculite, the soil is aerated naturally, and the roots are able to develop at a much faster rate.

Many gardeners also use vermiculite in conjunction with organic compost, adding it to the soil to prepare it for the roots that will develop when the seedlings are planted. In warmer climates, vermiculite maintains a steady level of aeration in the soil, maintaining hydration despite rising temperatures in the area.

Vermiculite is also used in some sorts of hydroponics systems.

Using Vermiculite in the Garden

When you add vermiculite to your soil, you should be ready to do it at 50 percent vermiculite and 50 percent compost.  Although plants can grow in just vermiculite, it cannot provide all of the nutrients that plants need.  If you choose to grow plants in just vermiculite, you’ll want to be prepared to supply ample fertilizer to feed your plants.

You want to dump the vermiculite in the soil and then work it in with a tiller.  The vermiculite will help to soften the soil.

It is best to add the vermiculite just before you add the seedlings to the garden so that once the roots enter the soil, they can begin rapid growth and moisture retention for the plant’s health. After you have planted the seedlings, feel free to add a small pinch or sprinkle of vermiculite around the plant before you give it the first watering in the new soil.

When I mix up my seed starting mix each spring, I add a large amount of vermiculite.  This helps to keep the starter mix soft and well-moistened for young seedlings.

Should I add vermiculite to my soil?

If you are planning to add vermiculite to your garden, you should first consider the type of soil you have and if vermiculite is the right option.

While it can pair well with some clay soils, those that have more clay than soil may find that the vermiculite makes the soil soggy and too watery for your plants. For soils that get very warm in the planting months and have the potential to have droughts or lose water to evaporation more than other areas, vermiculite is a must in the garden.

If you are looking to add vermiculite to your potted plants, you want to add it in the fourth ratio, with 3/4 of the soil as regular potting soil and the last fourth as vermiculite. Feel free to blend the vermiculite with your hands so that it has a more even spread in the soil.

The more even it is spread, the longer it will last and assist with retaining moisture for the plant.

If you are applying vermiculite to seeds during the germination process, you can create a vermiculite top layer so that moisture is retained on top, creating that greenhouse effect. Any time you add vermiculite to a pot or seedling container, make sure to drain the excess water after you have watered it for the first time.

Which is better: vermiculite or perlite?

When determining which substrate to add, you may consider adding perlite to the soil. This is an additive generated from volcanic rock and can also have water retention in the soil. Perlite is great for environments where the environment changes temperatures rapidly and often.

Because of this, perlite is ideal for cacti plants and succulents that grow in extremely hot temperatures. While it holds water like vermiculite, it does not hold as much. These plants that do not need as much water will drown with the use of vermiculite.

If your plants thrive on water and enjoy drinking water regularly, then you should consider adding vermiculite based on this alone. Perlite is more ideal for drought-resistant plants that do not need as much water as others in order to survive. If you use perlite for plants that thrive on excess water, they will not retain the appropriate water levels to survive in hot temperatures.

Vermiculite is a popular choice for adding to seed starting mixes.  In fact, many bagged seed mixes come with vermiculite mixed in.

For more about perlite vs. vermiculite, watch the video below:

Where can you buy vermiculite?

You can buy vermiculite at many garden supercenters and some nurseries.  Vermiculite is a soil additive and growing media that isn’t as common as soil mixes.  Instead, you may have to order it.

It’s extremely lightweight, which means that it’s probably cheaper than you may realize.  A large bag, 4 cubic feet, is very light and inexpensive to ship.

You can order vermiculite easily from Amazon.

You might also be interested in:

• Adding Calcium to the Soil

• What kind of soil texture do you have?

• Is soil alive?

• Fall Gardening Tasks: Soil

What do you use vermiculite for? Do you use vermiculite with your garden plants? Let me know below!