Terrariums at home: how to make them step by step, care, and the best plants

Guide to creating and maintaining a terrarium: materials, steps, maintenance, and plant selection

The terrariums they are authentic miniature gardens They add a touch of nature and elegance to any interior space. Beyond their decorative use, their value goes much further: improve air qualityThey help maintain optimal humidity and contribute to overall well-being by creating a relaxing environment. Thanks to their low maintenance, they're ideal for those who don't have much time to care for plants but still want to enjoy their beauty and benefits.

A terrarium isn't just a decorating trend: it's also a simple, educational, and fun project that you can do at home, alone or with your family. Below is a list of ideas. comprehensive guide to make your own terrarium, along with expanded information on types, internal workings, and maintenance, including key resources from experts and personal experiences, as well as scientific and practical knowledge acquired by amateur and professional gardeners.

What is a terrarium? Features and benefits

Un terrarium is a collection of small plants, carefully selected and placed inside a transparent container—usually made of glass—that acts as a mini greenhouse. These containers can have a wide variety of shapes (spherical, cubic, cylindrical, bottle-shaped) and can be closed (totally airtight) or open (with a top or side opening).

The defining feature of the terrarium is its ability to recreate a controlled environmentThis allows for the development of small, practically self-sufficient ecosystems, where plants irrigate themselves through transpiration and condensation. This way, maintenance is minimal, and the flora contained within is protected from external climatic fluctuations and pollutants.

• Decorative and functional: They improve air quality, increase ambient humidity, and act as a natural barrier against environmental pollution.
• Didactic: They allow us to observe and learn ecological concepts such as water and carbon cycles, nutrient recycling and the interaction between plant species and microorganisms.
• Adaptable to any space: Their compact design makes them perfect for small apartments, urban homes, offices, or rooms with limited space.

How does a terrarium work? Internal ecological dynamics

El internal function of a terrarium is a fascinating example of a closed cycle of water and nutrients. In closed terrariums, the sun or artificial light heats the air and the substrate, causing the water evaporation, which then condenses on the cold walls of the container. This creates a constant cycle: the moisture falls back into the soil, keeping the environment eternally moist with hardly any need for watering. As parts of the plants die, they decompose and return nutrients to the substrate, completing the nutrient cycle.

• Perspiration: Plants release water vapor, which condenses and forms small droplets on the walls of the glass.
• Condensation: The steam cools and returns to the ground, where it nourishes the plants again through their roots.
• Decomposition: Dead leaves and roots are degraded by microorganisms, releasing nutrients that are absorbed again.

This phenomenon makes well-designed terrariums self-sufficient for long periods. However, they require careful monitoring at least in their first few weeks to achieve the ideal balance between humidity, light, temperature, and ventilation.

Differences between open and closed terrariums

Not all containers are the same nor do they offer the same possibilities when it comes to choose plants, design, and functionality. There are two main groups of terrariums:

• Closed terrariums: These are those with lids or that can be sealed (bottles, airtight jars, balloons). They reproduce the humidity typical of tropical environments and are optimal for plants that require high humidity and stable temperatures, such as ferns, fittonias, mosses, and begonias. They are extremely self-sufficient, requiring only initial watering and occasional checks.
• Open terrariums: They have a wide mouth or no lid at all. They allow air circulation, making them more suitable for species that tolerate or prefer dry or semi-dry environments, such as cacti and succulents. They require more regular watering and close monitoring to prevent dehydration.

The type of terrarium will determine the most suitable plants. and the amount of care you will have to perform.

Step by Step: How to Make a Terrarium from Scratch

1. Select the container: Use a clear, clean, and dry container (glass jar, fishbowl, bottle, urn, etc.). The size will depend on the available space and your decorative preferences.
2. Prepare the drain: Cover the bottom with a layer of small rocks (pebbles, gravel or expanded clay). This prevents the ponding and prevents root rot.
3. Add activated carbon: On the stones, add a layer of activated carbon. Its function is filter the water, eliminate bad odors and prevent the growth of bacteria and fungi.
4. Place the substrate: Add specific soil according to the selected plants (substrate for tropical plants, indoor plants or for cacti and succulents).
5. Plant: Make small holes and introduce each plant depending on the desired composition. Gently press the soil to secure the roots. It's recommended to use small, slow-growing plants that tolerate the same light and humidity conditions.
6. Decorate: Add decorative elements such as moss, medium-sized stones, logs, figures, or colored sand.
7. Regar: Lightly moisten the substrate with a spray bottle. Don't overwater; just enough moisture to activate the water cycle.
8. Close (if applicable): Place the lid or seal in the case of closed terrariums.

Recommended materials for a successful terrarium

• Glass bowl (boat, urn, fish tank, bottle…)
• Small rocks or gravel for drainage, essential to avoid flooding.
• Activated carbon, which filters water and combats bacterial growth.
• Substratum: Use appropriate soil according to the type of plants (tropical, cactus, succulents).
• selected plants, ideally small in size and slow growing.
• Musgo (optional), which promotes moisture retention and landscape aesthetics.
• Decorative elements (medium-sized stones, figures, logs, etc.).
• Water sprayer or small watering can to maintain adequate humidity.
• Tools such as spoons, long tongs or chopsticks for handling in tight spaces.

Tip: Remember to wash all materials well to remove any spores or contaminants.

What plants should you choose according to the type of terrarium?

La choice of plants It's essential for the success and balance of the terrarium's ecosystem. Ideally, small, slow-growing species with similar humidity and light requirements should be grouped together. Below are the best options, grouped by terrarium type and ornamental function:

• Plants for closed terrariums (high humidity):
  • Fittonia spp. (Nervous plant): versatile, resistant and with varied colors.
  • nephrolepis high (Boston Fern): ideal for providing texture and lushness.
  • Pilea libanensis y Pilea involved: to create scenic covers and points of visual interest.
  • Peperomia spp.: great versatility and easy propagation.
  • Small ferns: like Asparagus setaceus, they give verticality and naturalness.
  • Begonia spp.: stand out for their decorative leaves and intense colors.
  • Leucobryum glaucum (cushion moss): to simulate meadows and provide extra moisture.
• Plants for open terrariums (semi-moist to dry):
  • Succulent (Sedum, Echeveria, Haworthia…): they grow well in dry environments and require little water.
  • Cactus: for desert compositions (in terrariums capless).
  • callisia repens: ideal for small containers and colorful details.
  • air plants (Tillandsia): they do not require substrate and adapt to various locations.
• Other popular plants for terrariums:
  • Ficus line up: climber, responsible for creating a jungle look.
  • selaginella apoda: mossy appearance, excellent for moist soils.
  • Soleirolia soleirolii: creates dense green carpets.
  • Drosera spp. (Sun Dew): Carnivorous option for advanced hobbyists.
  • Ribbon (Chlorophytum comosum), Small Calathea, Spatofilio, Syngonium podophyllum, Pilea peperomioides and other compact tropical plants.

Maintaining balance: optimal watering and humidity

El irrigation It is one of the critical points in the care of a terrarium. The frequency and quantity It depends mainly on the type of terrarium (closed or open) and the plants used:

• Closed terrariums: They only require occasional watering. If the substrate looks dry or the condensation disappears completely, apply water with a spray bottle. If excessive condensation or large drops persist for several days, aerate the substrate for a few hours to restore the balance.
• Open terrariums: Watering can be weekly or biweekly depending on evaporation and the needs of the plants, especially succulents.

Use lime-free or distilled water to prevent salt buildup and avoid over-wetting the foliage. Excessive moisture encourages the growth of fungi and bacteria.

Long-term maintenance, common problems and how to solve them

To ensure the longevity of your terrarium, it is important to regularly monitor the following aspects:

• Monitoring internal humidity: The condensation and evaporation cycle must be kept regular. Adjust ventilation or add water to correct any deviations.
• Pruning and growth control: Plants may grow larger than expected or compete with each other. Remove or prune leaves, shoots and stems that invade the space or collide with the lid.
• Glass cleaning: Regular cleaning prevents algae, dust, or other debris from clouding the glass and blocking light.
• Removing dead leaves: Remove decaying leaves and plants to prevent mold growth. Sprinkle cinnamon on them if signs of mold appear.
• Replacing plants and substrate: If some species do not thrive or the substrate becomes compacted, replace them partially or completely.
• Pest control: Visually inspect for mealybugs, mites, or common pests. You can introduce springtails or isopods for biological control.
• Avoid excessive use of fertilizers: Excess nutrients promote unwanted growth and ecological imbalance.

Artificial lighting in terrariums: types and recommendations

La lighting This is a key factor for success, especially if your terrarium is in a room with little natural light. The best options include:

• Full spectrum LED lights: They promote photosynthesis and produce very little heat, which prevents the terrarium from overheating.
• T5/T8 and CFL fluorescents: They provide adequate intensity, although they generate more heat than LEDs.
• Distance to light source: Place the light about 20-30 cm from the terrarium. Avoid lamps that can overheat the environment.
• Automatic timers: They simulate 8-12 hour diurnal cycles, facilitating the biological rhythm of plants.

Avoid direct sunlight, which can overburden the interior and burn the plants.

Main problems in terrariums and effective solutions

As living systems, terrariums can face various challenges. The most common are:

• Fungi and mold: They arise from excess moisture. Solution: Air out the terrarium and remove dead organic matter. Sprinkle cinnamon to combat the fungus.
• Pests: Mites or insects can be introduced with the plants. Solution: pre-inspection and use organic solutions such as insecticidal soap or biological control.
• Humidity imbalance: This occurs due to a lack or excess of condensation. Solution: adjust irrigation or ventilate as appropriate.
• Lighting problems: Too little water causes stretched stems and pale leaves; too much water dehydrates them. Solution: artificially adjust the intensity and location.
• Aeration and compaction of the substrate: Prevent with aerated substrates and occasional soil removal. Isopods and springtails help maintain soil structure and health.

Ideal location and specific care

• Place the terrarium in a bright area but without direct sunlight.This prevents overheating and moisture imbalance.
• Avoid heat sources or air conditioning, which can alter the temperature and dry out the environment.
• Choose a stable, low-traffic surfaceMake sure the terrarium is visible and protected from accidental falls.
• Maintain an appropriate height for appreciation and easy access for care.
• Do not place the terrarium near electronic devices that generate excessive heat or environmental dryness.

Keys to the nutrient cycle and biodiversity in the terrarium

The long-term success of a terrarium depends on its nutrient cycle and the presence of beneficial fauna and flora:

• Bacteria, fungi and decomposers They recycle organic matter and maintain the fertile substrate.
• Springtails and mites control mold buildup and process waste.
• Mosses and lichens They contribute to humidity regulation and serve as microhabitats.

Frequently asked questions: duration, watering and additional recommendations

Un well-balanced terrarium It can be maintained for years, even decades, as long as humidity is monitored, occasional pruning is performed, and exposure to sudden temperature changes is avoided. eternal terrariums They don't require frequent watering; visually monitor the moisture level and make adjustments only when necessary.

The terrarium is a versatile, eco-friendly, and eye-catching option for both decoration and gift-giving. Its ability to adapt to different styles and spaces, its educational value, and its dynamic nature as a self-contained ecosystem make it a perfect activity for any plant lover, regardless of experience level. Dare to create your own and immerse yourself in the fascinating world of small indoor ecosystems.