How to care for your Terrarium - A beginner's guide. Looking after your terrarium.
- Kristina Harper
- Apr 2
- 4 min read
At The Green Emporium, we want you to feel confident in caring for your terrarium. That’s why we’re here to provide you with all the essential information to help your new plant baby thrive!
What is a Terrarium?
A terrarium is a self-sustaining miniature ecosystem that allows both plant enthusiasts and beginners to enjoy greenery in an enclosed environment. Designed to mimic nature, a properly sealed terrarium regulates its own atmosphere, maintains a water cycle, and stabilizes internal temperatures. Terrarium care is easy when this is mimicked.
Many products on the market claim to be terrariums, but if they don’t create their own water cycle, they’re simply plants in a glass container. Open glass bowls or jars with plants are beautiful displays, but they don’t function as true terrariums.
Understanding Your Terrarium’s Natural Processes
To maintain a thriving terrarium, it’s important to understand the key biological processes at play: photosynthesis and respiration. These two processes work together, ensuring a continuous cycle of energy and moisture within the terrarium.
Photosynthesis – Harnessing Light for Growth
Light is the most crucial factor in keeping your terrarium healthy. A bright, indirect light source (such as filtered sunlight) provides the energy plants need to photosynthesize. Within the enclosed space, plants absorb carbon dioxide from the air and recycle moisture through the terrarium’s rain cycle. Since growth is naturally slower in a terrarium, the nutrients present in the soil are usually sufficient to sustain the plants.
Respiration – The Self-Sustaining Rain Cycle
Once a terrarium is properly hydrated, it establishes its own self-sustaining water cycle. Here’s how it works:
Moisture is absorbed by plant roots.
Water then moves through the plant and is released as vapor through the leaves in a process called transpiration.
This vapor condenses on the glass, creating fog.
Over time, the condensation forms droplets that "rain" back into the soil, rehydrating the plants.
This natural cycle repeats continuously, reducing the need for frequent watering and allowing your terrarium to flourish with minimal maintenance.
By understanding and embracing these processes, you’ll be able to enjoy a thriving, low-maintenance slice of nature right in your home!
Terrarium care - Bringing home a new terrarium
It's exciting, but it requires a little attention during the first couple of weeks as it adapts to its new environment. By closely monitoring it, you can prevent issues like mold growth, excessive condensation, or overwatering.
Finding the Perfect Location
Placement Matters! The location of your terrarium is the most crucial factor in its long-term health. Here’s how to find the perfect spot:
Where to Place Your Terrarium
Choose a room with bright, indirect light—never place your terrarium in direct sunlight, as this can overheat and damage the plants.
Keep it away from heat sources or air-conditioning vents to prevent temperature fluctuations.
Aim to provide as much light as possible while avoiding overheating.
Cold Rooms vs. Warm Air Inside the Terrarium
The air inside a terrarium is slightly warmer than the surrounding environment.
If cold air enters the room (e.g., from an open window in the morning), condensation will naturally form inside the terrarium. This is normal and should clear up as the room warms.
Some condensation is expected, but if the glass stays excessively foggy, adjustments may be needed.
Preventing Mold Growth
That little white or grey fluffy stuff on leaves and stems? That’s mold! It can naturally occur, but if left unchecked, it spreads quickly.
How to remove mold:
Wipe it off gently using a dry cloth or cotton swab (never reuse the same swab).
Clean the surrounding area to remove any spores.
Wash your hands after handling mold.
If mold appears, open the terrarium lid for 12 hours overnight (the coolest part of the day) to allow excess moisture to escape—mold doesn’t like fresh air!
Watering Your Terrarium
At The Green Emporium, we typically water our closed terrariums every 4 months—but only if they look dry. Here’s how to tell if your terrarium needs water:
The glass stays completely clear (no condensation).
The soil looks visibly dry.
Moss appears pale or plants look droopy.
How to Water Correctly
Lightly mist the base of the plants using rainwater or distilled water (avoid tap water, which can cause buildup).
Terrariums don’t have drainage, so add water slowly to prevent overwatering.
Some tightly sealed terrariums can go a year or more without additional watering!
When in doubt, don’t water. Overwatering is the fastest way to kill a terrarium.
Pruning & Cleaning
Regular pruning keeps plants healthy—trim back fast growers before they overshadow slower-growing species.
Remove any dead leaves or vegetation as soon as you notice them.
If plants touch the glass, trim them back to prevent overcrowding.
Cleaning the Glass
Use a paper towel with a small amount of glass cleaner—spray the towel, not the terrarium itself.
If algae forms, gently wipe it away. Algae is natural, but if left unchecked, it can block light and harm plants.
Clean glass = healthy plants!
Fertilizing
Terrariums rarely need fertilizer. Only use it if plants show signs of malnutrition, such as yellowing or loss of vibrancy.
How to fertilize properly:
Use a diluted all-purpose liquid fertilizer (1/3 of the recommended strength).
Apply sparingly with a spray bottle, targeting leaves and roots.
Fertilizing too often encourages rapid growth, which isn’t ideal for a terrarium.
Insect Management
Most insects are harmless, but some can be troublesome:
Slugs, snails, caterpillars – Remove them immediately, as they will damage leaves.
Fungus gnats – The most common pest in terrariums. Use pyrethrum spray (low-toxicity insect spray) on the glass, not the plants. Repeat every few days until the cycle is broken.
Quick Troubleshooting Guide - Terrarium care, looking after your terrarium.
Issue | Cause | Solution |
Smelly Terrarium | Overwatering, lack of light | Reduce watering, move to a brighter location |
Crispy brown leaves/tips | Dehydration | Lightly water at plant base |
Moss turning brown | Lack of water or light | Mist thoroughly and move to brighter light |
Yellow, mushy, dropping leaves | Too much moisture, insufficient light | Move to a brighter location, air out overnight |
Plants growing tall and "reaching" | Not enough light | Move to a brighter spot |
Excessive condensation | Temperature fluctuations | Move to a stable environment |
By following these simple care tips looking after your terrarium can be easy and, your terrarium will thrive with minimal maintenance. Enjoy your little slice of nature! 🌿
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