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Best Type of Soil Used for Terrariums

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If you are willing to create a fascinating display, hedge a small garden in a glass container to form a terrarium. Unlike an outdoor garden, a terrarium provides a humid and moist atmosphere with everything your plants need and with very little maintenance, provided you use the correct type of soil. Soil is just a part of likeliness. Soil layering provides wastewater, the right amount of humidity, and an odorless surrounding produces the best outcome.

What Soil Is Best For Terrariums

Selecting the soil for these terrariums can be a challenge. Various environmental factors can cause the soil to dry out, hence different types of soil will be suitable for growing in different areas. The areas where you live and the spot where you place your terrariums play a vital role in determining the kind of soil they require.

Read on to know the best type of soil for Terrariums

What Soil is Best For Terrariums

Terrariums do not offer as much aeration of under roof plants as required. Hence, it is said that using the perfect choice soil is more vital for the wellness of these small ecosystems inside a glass container.

It is highly recommended to use the soil, which is a mix of Drainage, Activated Charcoal, Sphagnum Moss, and Potting soil.


Drainage is of crucial importance when considering the growth of plants because excess water will harbor the growth of microbes and rotten or kill the plant. Also, when you are considering a miniature garden in a container, this stands very important, so the first layer of soil used in a terrarium would be gravel or small rocks. This facilitates drainage. Some people prefer using chips of granite or marble or crushed pots as drainage material. All the material that you wish to add must’ve sterilized to prevent contamination and disturbance to the ecosystem.

The initial layer in a terrarium’s soil is a smooth layer of gravel or small rocks. The main aim of gravel is to help in drainage. So, before adding drainage material to the terrarium, clean it to avoid unwanted bacteria to the ecosystem.

Activated Charcoal

Activated charcoal imbibes harmful organic chemicals. One everyday use of activated charcoal is to purify water. About half of the activated charcoal passes the drainage material in a terrarium. Few growers mix the charcoal with the drainage material or choose not to include the activated charcoal at all. The main aim of the charcoal is to eliminate unpleasant odors and also eliminate harmful chemicals that are dangerous and toxic to plants.

Activated carbon in the charcoal absorbs all harmful chemicals. This is used as a purification system. The water is then purified through activated charcoal. So this is added after the drainage material.

Sphagnum Moss

Sphagnum Moss is also known as the Bog Moss. A layer of sphagnum moss shields the activated charcoal layer while preparing the terrarium soil. The main aim of this activity is to remove the potting soil from the activated charcoal and gravel, stopping the potting soil from mixing into the gravel or rocks.

Bog moss is added covering the activated charcoal, and this separates the potting soil and the bottom layers. Thus, this type of soil prevents the falling of soil into gravel or activated charcoal. This keeps all the layers separated and prevents the development of mold.

Photo Credit: Instagram @terrajardim

Potting Soil

The potting soil is the first layer. The gravel, activated charcoal and moss should not take more than three fourth of the volume of the terrarium. The potting soil can be regular houseplant soil or any commercial one. African violet mix is an excellent soil suitable for terrarium and one can also prepare excellent soil by combining sterilized soil with peat moss and vermiculite in equal proportions.

The first layer of the terrarium is the mixture of Potting. Blend of all the soil – from the gravel to the potting mix, must not be more than 4/5th of the terrarium’s mass. Still, the potting soil needs to be at least 1 ½” in depth. It is not essential to buy a man-made pot soil. Instead, you can prepare the potting mix by mixing the same quantity of all the ingredients (sterilized soil, vermiculite and peat moss) to make the potting mix. Vermiculite is a natural mineral, and moss is dried decayed vegetation. Both are available ate the gardening retailers.

Terrariums are customizable with self-regulating capacity and are available in low maintenance and costs. There are also great gifting options spreading greenery and promoting the growth of plants across the globe. You may consider trying one as this requires less space and enhances your creativity.

How Does This Soil Work?

The main component of any soil mix for terrariums will be refined materials. Peat moss, the prime ingredient, is the important soil, is rigid to moist, and dries very quickly. By adding a few fine bark powders, water will escape soon. For handmade ingredients, an excellent replacement for peat moss is jute, a highly fibrous husk of the coconut, and takes a very long time to decompose. Besides, jute is natural to moist when it dries completely.

Another critical ingredient is a man-made material that allows water to soak and escapes out of the soil quickly. There are several best options such as volcanic glass, crumpled sandstone, and much more which is used to improve aeration. All these will desperately maximize drainage and doesn’t disintegrate as the organic material decays slowly.

How Do You Mix Soil for a Terrarium?

Mixing soils is easy if you have access to some basic tools like a spoon, measuring cup, and spatula. Mixing the right amount of each ingredient is crucial because too little or too much could result in poor drainage and slow plant growth. If you don’t know what kind of soil mixes would suit your terrarium, then you need to consult someone who has experience on making them. You can use either dry or wet method to blend the soil.

Wet blending involves using a watering can to add moisture into the soil while stirring until blended well. Dry blending uses only a spoon and no other tool. This way is faster but might leave behind lumps of soil. In both methods, you’ll want to stir thoroughly so there aren’t clumps left over.

Can I Use Succulent Soil for Terrarium?

Succulent soil is made up of different types of clay minerals mixed together. Succulent soil is usually sold in small bags containing about 2 pounds per bag. The reason why they’re called “succulent soil” is because their texture resembles the fleshy leaves of succulents. They contain nutrients needed for growing succulents. However, most people prefer not to use succulent soil since it contains fewer nutrients.

How Many Inches of Soil Do I Need for a Terrarium?

You can get by with just 1/2 inch of soil for every 3 feet. But if you plan to grow larger plants, you’d better increase the depth accordingly. It’s recommended to keep at least 4 inches of soil for every foot, depending upon the size of the container.

Do I Need to Fertilize My Terrarium?

Fertilizing your terrarium helps promote healthy root development and increases its overall health. Some common fertilizer include: fish emulsion, kelp meal, composted manure, alfalfa pellets, worm castings, seaweed extract, bloodmeal, bone meal, greensand, rock dust, and others. These all help stimulate roots and encourage new growth.

Final Words

Soil is of great importance when housing a garden in a terrarium because you are creating an ecosystem on a small scale. You are mimicking the earth when you are creating this terrarium. There will be some standard soil profiles for a successful terrarium. Let’s get into the nitty-gritty of it.

Hope by now you would have known the best soil to be used for your beautiful and decorative terrariums. Ensure that you do not let things get too stressful since terrarium planting is supposed to be a lot of fun and remedial.