What is a Terrarium?
A terrarium is a miniature garden enclosed in a glass container, creating a self-contained ecosystem that mimics natural environments. Originally invented in the 1840s by botanist Nathaniel Bagshaw Ward, terrariums have become popular for their low maintenance requirements and ability to bring nature indoors.
Whether you live in a small apartment, have limited outdoor space, or simply want to add some greenery to your desk, terrariums offer a beautiful and practical solution. They require minimal care once established and can thrive for years with proper setup.
Why Build a Terrarium?
- Low Maintenance: Closed terrariums may only need watering every few months
- Space Efficient: Perfect for desks, shelves, and small living spaces
- Educational: Learn about ecosystems and plant biology
- Therapeutic: Building and maintaining terrariums can reduce stress
- Decorative: Adds natural beauty to any room
Types of Terrariums
Understanding the two main types of terrariums is essential for choosing the right plants and care routine.
Closed Terrariums
Sealed containers that create their own water cycle through condensation. Water evaporates from the soil and plants, condenses on the glass, and drips back down.
Best For:
- Tropical plants
- Ferns and mosses
- High-humidity lovers
- Forgetful waterers
Pros:
- Self-sustaining once balanced
- Rarely needs watering
- Creates beautiful condensation effects
Cons:
- More sensitive to temperature changes
- Can develop mold if overwatered
- Limited plant choices
Open Terrariums
Containers without lids that allow air circulation. These require more frequent watering but offer greater plant variety and are more forgiving of mistakes.
Best For:
- Succulents and cacti
- Air plants
- Desert plants
- Beginners
Pros:
- Wider variety of plants
- Less prone to mold
- More forgiving of errors
Cons:
- Requires regular watering
- More susceptible to pests
- Dust can accumulate on plants
Materials You'll Need
Gathering the right materials before you start ensures a healthy, long-lasting terrarium. Here's everything you'll need:
Glass Container
Choose a clear glass container appropriate for your terrarium type. For closed terrariums, look for jars with airtight lids. For open terrariums, geometric containers, bowls, or vases work well.
Tip: Wider openings make planting easier, especially for beginners.
See glass terrarium jars on Amazon →Drainage Layer
Small pebbles, gravel, or lava rocks form the bottom layer (1-2 inches). This prevents water from pooling around roots and causing rot. Lava rocks are excellent as they're lightweight and porous.
Check price on Amazon →Activated Charcoal
A thin layer of horticultural charcoal (about 1/4 inch) acts as a filter, absorbing odors, toxins, and excess moisture. This is especially important for closed terrariums where air doesn't circulate.
See horticultural charcoal on Amazon →Sphagnum Moss
A layer of sphagnum moss between the charcoal and soil acts as a barrier, preventing soil from sinking into the drainage layer while retaining moisture.
See sphagnum moss on Amazon →Terrarium Soil
Use soil appropriate for your plants. For tropical terrariums, a mix with good drainage works best. For succulents, use cactus soil. Pre-mixed terrarium soil contains the right blend of nutrients and drainage materials.
See terrarium soil mix on Amazon →Tools
Long tweezers, scissors, and a small brush help you work in tight spaces. A spray bottle provides gentle watering without disturbing the layers.
See terrarium tool sets on Amazon →Want Everything in One Package?
Terrarium starter kits include all the essential materials you need to get started, often with tools and care guides included. Great for beginners or as gifts.
View Starter Kits on AmazonHow to Build Your Terrarium
Follow these steps to create a thriving terrarium. The entire process takes about 30-60 minutes.
Clean Your Container
Wash your glass container thoroughly with soap and water, then dry completely. Any residue or bacteria could harm your plants or cause mold growth. For extra precaution, rinse with diluted white vinegar.
Add the Drainage Layer
Pour 1-2 inches of small pebbles, gravel, or lava rocks into the bottom of your container. This layer should be about 1/6 of the container's total height. Spread evenly for consistent drainage.
Add Activated Charcoal
Sprinkle a thin layer (about 1/4 inch) of activated charcoal over the drainage layer. This keeps your terrarium fresh by filtering water and absorbing impurities. Don't skip this step for closed terrariums.
Add Sphagnum Moss Barrier
Place a thin layer of sphagnum moss over the charcoal. This creates a barrier that prevents soil from trickling down into the drainage layer while helping retain moisture near the roots.
Add Potting Soil
Add 2-3 inches of appropriate potting soil, depending on your container size and plant root depth. Create small hills or valleys for visual interest. Leave enough space for your plants plus some headroom.
Plant Your Plants
Remove plants from their pots and gently loosen the roots. Using long tweezers or chopsticks, create holes in the soil and place your plants. Start with the largest plant as a focal point, then add smaller plants around it. Press soil firmly around each plant.
Add Decorative Elements
Enhance your terrarium with decorative moss, small stones, driftwood, or figurines. Sheet moss can cover exposed soil for a more natural forest-floor look. Keep decorations minimal to avoid overcrowding.
Water Lightly
Use a spray bottle to mist the plants and soil lightly. For closed terrariums, less is more—you can always add water but removing excess is difficult. The soil should be moist but not soggy.
Final Touches
Clean any soil or water spots from the inside glass with a long brush or paper towel. For closed terrariums, place the lid on top. Position your terrarium in its permanent home with appropriate lighting.
Pro Tips for Success
- Plan your layout: Arrange plants outside the container first to visualize the design
- Work from back to front: Plant taller specimens in the back, shorter ones in front
- Leave breathing room: Don't overcrowd—plants will grow
- Use odd numbers: Groups of 3 or 5 plants look more natural than even numbers
Choosing the Right Plants
Selecting compatible plants is crucial for a successful terrarium. Choose plants with similar light and humidity requirements.
Best Plants for Closed Terrariums
These plants thrive in humid, low-light conditions:
Fittonia (Nerve Plant)
Colorful leaves with pink, white, or red veins. Compact growth makes it perfect for small containers. Thrives in humidity and low light.
- Light: Low to medium
- Humidity: High
- Growth: Slow
Ferns (Various Species)
Delicate fronds add texture and movement. Maidenhair, button, and miniature ferns work well. Love the humid environment of closed terrariums.
- Light: Low to medium
- Humidity: High
- Growth: Moderate
Moss
Creates a lush forest floor effect. Sheet moss, mood moss, and cushion moss all work beautifully. Essential for that classic terrarium look.
- Light: Low
- Humidity: High
- Growth: Slow
Peperomia
Compact plants with varied leaf shapes and colors. Peperomia caperata and prostrata are excellent choices. Tolerant of varied conditions.
- Light: Medium
- Humidity: Medium-High
- Growth: Slow
Selaginella (Spikemoss)
Looks like a tiny forest of ferns. Creates excellent ground cover. The 'Golden' variety adds color variation.
- Light: Low to medium
- Humidity: High
- Growth: Moderate
Polka Dot Plant
Spotted leaves in pink, red, or white add visual interest. Compact hybrids stay small. May need occasional pruning.
- Light: Medium
- Humidity: Medium-High
- Growth: Moderate
Best Plants for Open Terrariums
These plants prefer drier conditions with good air circulation:
Succulents
Echeveria, Haworthia, and Sempervivum store water in their leaves. Perfect for low-maintenance open terrariums. Come in endless varieties.
- Light: Bright indirect
- Humidity: Low
- Growth: Slow
Air Plants (Tillandsia)
No soil needed—they absorb water through their leaves. Simply mist or soak weekly. Creative mounting options make them versatile.
- Light: Bright indirect
- Humidity: Low-Medium
- Growth: Slow
Small Cacti
Desert cacti add interesting shapes and occasional flowers. Choose small, slow-growing varieties. Handle with care due to spines.
- Light: Bright
- Humidity: Low
- Growth: Very slow
String of Pearls
Trailing succulent with bead-like leaves. Cascades beautifully over container edges. Needs bright light to thrive.
- Light: Bright indirect
- Humidity: Low
- Growth: Moderate
Plants to Avoid
- Fast growers: They'll quickly outgrow the container and crowd other plants
- Large plants: Choose miniature or dwarf varieties
- Sun lovers in closed terrariums: Plants needing full sun won't thrive in low-light humid environments
- Succulents in closed terrariums: They'll rot in the high humidity
Care and Maintenance
Proper care ensures your terrarium thrives for years. The good news is that terrariums are designed to be low maintenance.
Watering
Closed Terrariums:
Water sparingly, usually every 2-4 weeks or when condensation disappears completely. If heavy condensation covers the glass, leave the lid off for a few hours to let excess moisture escape.
Open Terrariums:
Check soil moisture weekly. Water when the top inch feels dry. Succulents need water every 1-2 weeks; tropical plants may need more frequent watering.
Light
Place your terrarium in bright, indirect light. Direct sunlight can overheat the enclosed environment and burn plants. A spot near a north or east-facing window is ideal.
Signs of too much light: Yellowing leaves, brown spots, wilting
Signs of too little light: Leggy growth, pale leaves, slow growth
Temperature
Most terrarium plants prefer temperatures between 60-75°F (15-24°C). Avoid placing near heating vents, air conditioners, or drafty windows. Consistent temperature is more important than specific ranges.
Pruning
Trim plants that touch the glass or grow too large. Remove any dead or yellowing leaves immediately to prevent mold. Regular pruning keeps plants compact and encourages bushy growth.
Troubleshooting Common Problems
Mold or Fungus
Cause: Too much moisture, poor air circulation, or dead plant material.
Solution: Remove affected areas immediately. Leave the lid off for 24-48 hours to dry out. Reduce watering frequency. Ensure charcoal layer is adequate.
Yellowing Leaves
Cause: Overwatering, too much light, or nutrient deficiency.
Solution: Check soil moisture before watering. Move away from direct light. Yellowing is often a sign of stress—identify and correct the environmental issue.
Foggy Glass
Cause: Normal condensation cycle in closed terrariums.
Solution: Light morning fog is healthy. If glass is constantly covered with heavy droplets, open the lid for a few hours daily until balance is achieved.
Wilting Plants
Cause: Underwatering, overwatering, or heat stress.
Solution: Check soil moisture. If dry, water thoroughly. If wet, let it dry out and improve drainage. Move away from heat sources.
Leggy Growth
Cause: Insufficient light causing plants to stretch toward light source.
Solution: Move to a brighter location with indirect light. Prune leggy stems to encourage compact growth. Rotate the terrarium periodically.
Pests
Cause: Introduced with plants or soil, or attracted by open containers.
Solution: Remove visible pests manually. For fungus gnats, let soil dry between waterings. Isolate affected terrariums. As a last resort, remove and replace affected plants.
Recommended Products
These are our top picks for building and maintaining beautiful terrariums.
Starter Kits
Perfect for beginners, these kits include everything you need to get started.
Cute Farms Terrarium Starter Kit (Large)
Complete kit with moss, vermiculite, soil, pebbles, plant food, and tools. Includes care guide. Great for first-time builders.
Check Price on AmazonCute Farms Terrarium Starter Kit (Small)
Compact version with all essentials for smaller terrariums. Perfect for desk-sized projects or as a gift.
Check Price on AmazonDIY Terrarium Kit (13 Items)
Comprehensive kit with soil, pebbles, sphagnum moss, activated carbon, peat moss, tools, and fairy lights for decoration.
Check Price on AmazonGlass Containers
Quality containers make all the difference in presentation and functionality.
Glass Terrarium with Airtight Wood Lid (Large)
1200ml/40oz jar with beautiful cork top. Perfect for closed terrariums. Creates ideal humidity levels.
Check Price on AmazonGlass Terrarium with Airtight Wood Lid (Medium)
800ml/27oz version for compact terrariums. Same quality construction in a smaller size.
Check Price on AmazonULTECHNOVO Glass Terrarium Jar
Elegant design with wood stopper. Great for both open and closed setups. Modern aesthetic.
Check Price on AmazonSupplies & Materials
Essential materials for building healthy, long-lasting terrariums.
Horticultural Charcoal (4qt)
Perfect Plants brand activated charcoal. Naturally cleanses, flushes toxins and excess moisture. Essential for closed terrariums.
Check Price on AmazonGalápagos Green Sphagnum Moss
Long-fiber leafy sphagnum moss. Creates ideal humidity barrier. Long-lasting and natural-looking.
Check Price on AmazonTerrarium Potting Soil Mix (4qt)
Soil Sunrise blend with coco coir, pumice, and charcoal. Custom-made for terrariums. Promotes drainage and healthy roots.
Check Price on AmazonBlack Lava Rock for Drainage
6lb bag of natural volcanic grit. Excellent for drainage layer. Lightweight and porous.
Check Price on AmazonTools
The right tools make planting and maintenance much easier.
VORESTIC 6-Piece Aquascape Tools
Complete set with long tweezers, scissors, spatula, and scraper. Stainless steel construction. Includes storage bag.
Check Price on AmazonMIZOMOR 4-Piece Tool Kit
Stainless steel tweezers (straight and curved), scissors, and scraper. Perfect for precise planting work.
Check Price on AmazonMandala Crafts Aquascaping Tools
Essential scissors and tweezers set. 10+ inch length for reaching into deep containers.
Check Price on AmazonPlants
Start with quality plants for the best results.
Mini Ferns (6 Plants)
Assorted mini ferns in 2" pots. Perfect for terrariums and fairy gardens. Non-toxic to pets.
Check Price on AmazonFor Kids
Fun terrarium kits designed specifically for young builders.
Creativity for Kids Grow 'N Glow Terrarium
Science kit with glow-in-the-dark elements. Includes seeds, soil, and figurines. Perfect STEM gift.
Check Price on AmazonFrequently Asked Questions
How long do terrariums last?
With proper care, terrariums can last for years or even decades. Closed terrariums are especially long-lived because they create a self-sustaining water cycle. The oldest known terrarium was sealed in 1960 and thrived for over 50 years without being opened.
Can I use regular potting soil?
It's best to use soil specifically formulated for terrariums or the type of plants you're growing. Regular potting soil may retain too much moisture for closed terrariums or lack proper drainage. For succulents, always use cactus/succulent mix.
Do terrariums need sunlight?
Terrariums need light but not direct sunlight. Direct sun can overheat the enclosed environment and burn plants. Bright, indirect light—such as near a north-facing window or a few feet from a sunny window—is ideal.
Why is my closed terrarium always foggy?
Some condensation is normal and healthy—it's part of the water cycle. If heavy fog covers the glass constantly, there's too much moisture. Leave the lid off for a few hours each day until balance is achieved. Light morning mist that clears by afternoon is ideal.
Can I mix succulents and tropical plants?
No, these plants have opposite needs. Succulents need dry conditions and will rot in high humidity, while tropical plants need moisture and will dry out in succulent-appropriate environments. Keep them in separate terrariums.
How do I know if my terrarium needs water?
For closed terrariums, water when there's no condensation on the glass. For open terrariums, check the soil—if the top inch is dry, it's time to water. When in doubt, wait a few more days. Underwatering is easier to fix than overwatering.
What size container should I use?
Start with at least a quart-sized container for your first terrarium. Larger containers are more forgiving of mistakes because they provide more stable temperature and humidity. Very small containers require precise care and are best for experienced builders.
Do I need to fertilize my terrarium?
Generally, no. Terrariums are designed to be low-nutrient environments to keep plant growth slow and manageable. If plants show signs of nutrient deficiency after a year or more, use a very diluted liquid fertilizer sparingly.