How to Keep Humidity Up in a Terrarium

Keeping the right humidity in a terrarium is crucial to creating a lush, thriving environment for plants and, if you have them, small reptiles or amphibians. From tropical terrariums filled with ferns and mosses to mini desert landscapes, each type of terrarium has its own moisture needs. So, how do you create humidity, keep it stable, and control it effectively in your plant terrarium?

Why Humidity is Important in a Terrarium

Humidity plays a big role in the health of your terrarium plants and any inhabitants. High humidity is essential for moisture-loving plants like ferns, moss, and other tropical varieties.

• Supports Healthy Plant Growth: Keeping humidity high ensures that plants have the moisture they need for healthy growth.
• Reduces Plant Stress: Plants lose water quickly in dry environments, leading to stress and potential browning or shriveling.
• Ideal for Humidity-Dependent Animals: Reptiles or amphibians like frogs and geckos need humidity for skin health, breathing, and hydration.
• Creates a Balanced Mini Ecosystem: In a closed terrarium, high humidity encourages a self-sustaining, balanced environment that supports plant health and minimizes watering needs.

If you’re interested in learning about the role of different layers in creating an ideal terrarium environment, check out our guide on How to Make Terrarium Layers.

Maintaining the right humidity ensures your plants and animals feel right at home, providing them with a healthy atmosphere to thrive. Whether you’re aiming for a lush, tropical vibe or a cozy haven for your pets, keeping humidity stable is key to a happy, mini ecosystem.

Factors That Affect Humidity in a Terrarium

Several factors impact how well your terrarium holds moisture. By understanding these elements, you can make adjustments to ensure your plants and pets get the ideal environment.

• Enclosure Type: Closed terrariums hold moisture better than open ones. Glass enclosures, in particular, help retain humidity far more effectively than mesh or plastic.
• Plant Types: Humidity-loving plants like ferns and mosses naturally keep humidity high. On the other hand, succulents prefer lower humidity.
• Ventilation: More ventilation leads to faster water evaporation, decreasing humidity levels.
• Room Environment: Ambient room humidity impacts your terrarium, especially if the room is air-conditioned or heated, which can dry out the air.

Simple Ways to Keep Humidity Up in Your Terrarium

If you’re wondering how to bring up humidity and maintain it without much hassle, try these effective methods.

Use a Water Tray or Humidity Tray

A water or humidity tray is an easy way to increase humidity in your terrarium without a lot of maintenance. Here’s how it works:

• Place a shallow tray of water at the bottom of your terrarium, just below the soil or plant layer.
• The water evaporates slowly, naturally increasing humidity.
• Great for open or semi-closed terrariums that need a bit more moisture.

Humidity trays are especially useful for tropical setups. They help maintain humidity without oversaturating the soil, which can lead to mold. The water tray acts as a slow-release moisture source, providing just the right amount of humidity over time.

Add Sphagnum Moss or Moisture-Retentive Substrate

Using moss under the soil layer is a tried-and-true method to keep humidity levels stable. Sphagnum moss is excellent for moisture retention and releases water gradually.

• Benefits of Moss: Adds a long-lasting source of moisture, which helps with humidity control in terrariums.
• Layering Tip: Place the moss just under the soil layer to increase humidity without making the top soil too damp.

For more on why moss is an essential part of terrarium care, take a look at our article on Why Put Moss Under Soil in a Terrarium. By creating a moss layer, you help the terrarium maintain steady moisture, which can reduce how often you need to mist or water.

Mist Regularly with a Spray Bottle

Misting is a quick and easy way to keep humidity levels high. A light misting every few days can help regulate humidity in a closed or open terrarium.

• Frequency: Lightly mist plants and the terrarium walls every few days, or as needed.
• Avoid Overdoing It: Too much water can lead to mold, so a light spray is often sufficient for closed terrariums.

Regular misting allows you to increase humidity instantly, but make sure not to oversaturate the soil, as excess water can encourage fungal growth.

Incorporate a Mini Humidifier

A small humidifier can be placed near the terrarium to increase the surrounding humidity, especially during dry seasons.

• Location: Place it near open terrariums, or in the room to boost ambient moisture.
• Helpful in Dry Seasons: Indoor air tends to be drier during winter, so a mini humidifier is a good solution to maintain high humidity levels.

Mini humidifiers are also great if you have humidity-loving reptiles or amphibians that require a consistently humid environment.

Tools to Monitor and Control Humidity in Your Terrarium

Monitoring humidity with the right tools helps you make adjustments as needed to keep a healthy balance. Here are some simple devices that make it easy.

Hygrometers

A hygrometer is essential for tracking humidity levels in your terrarium.

• Digital vs. Analog: Both types work, but digital hygrometers provide more accuracy.
• Placement: Place it where you can easily read it without opening the terrarium too often.

This handy device gives you real-time readings of humidity levels so you can adjust as necessary to keep high humidity levels stable.

Humidity Gauges with Temperature

Humidity gauges that include temperature readings give you a full picture of the terrarium environment, which is crucial for fine-tuning your setup. Many humidity-loving plants and reptiles need a specific combination of temperature and moisture to thrive.

Timers for Misting or Humidifiers

Automating misting or humidifier use with timers can help maintain consistent moisture levels without constant manual adjustments. This is especially helpful in managing high humidity in larger terrariums.

Long-Term Tips for Maintaining Humidity in a Terrarium

To keep high humidity over time, here are a few more strategies.

Adjust Lighting and Temperature

Heat from lights can cause water to evaporate more quickly. Adjusting light distance or using low-heat LED lights helps prevent rapid humidity loss.

If you’re curious about how UVB light affects plant growth and its impact on terrariums, check out our in-depth guide on Would a UVB Light Grow Plants in a Terrarium?.

Reducing heat levels helps control how quickly moisture evaporates, ensuring the terrarium maintains a steady level of humidity.

Partially Cover Open Terrariums

For open terrariums, placing a piece of glass or plastic over part of the top can help control humidity by slowing evaporation while still allowing some airflow. This is a great way to change humidity levels without adding too much water or mist.

Group Humidity-Loving Plants Together

Plants that release moisture, like ferns and mosses, create a humid microenvironment, helping each other by collectively boosting moisture levels. Grouping these plants makes it easier to keep humidity up without needing to mist as frequently.

Choose Closed Terrariums for High-Humidity Plants

Closed containers are perfect for plants with high moisture needs because they maintain a stable environment, reducing the need for frequent misting or external humidity sources. If you want to avoid continuously monitoring and adjusting, a closed terrarium is a practical choice for high-humidity plants.

FAQs

How do I keep the humidity up in my enclosure?
To keep humidity up in your enclosure, use a water or humidity tray, add moisture-retentive substrate like sphagnum moss, mist regularly, or place a mini humidifier nearby. Closed enclosures are best for maintaining high humidity.

How can I raise the humidity quickly?
You can raise humidity quickly by misting the enclosure lightly or adding a small water dish. For faster, long-term effects, try adding damp moss or using a humidity tray.

How do I stop condensation in my terrarium?
To reduce condensation, improve ventilation, slightly decrease misting frequency, or adjust lighting to avoid excessive heat. Partially opening the enclosure can also help reduce moisture buildup on the walls.

How do I make my enclosure less humid?
Lower humidity by increasing airflow, reducing misting frequency, or using a dehumidifier nearby. Choosing low-humidity plants or using an open enclosure design can also help.

Wrapping Up

Creating and maintaining the right humidity in a terrarium is essential to keeping your plants and, if applicable, animals happy. From using water trays and misting to monitoring with hygrometers, there are many effective ways to control humidity in your terrarium. With just a few adjustments, you can keep humidity high and stable, creating a lush environment that mimics the plant’s natural habitat.