Growing Venus flytraps is easy! However, growing Venus flytraps in a terrarium is not so easy!! Some growers have success growing Venus flytraps in terrariums indoors. It’s certainly not impossible to achieve. But terrarium life for a Venus flytrap is not the easiest nor safest method for growing them. Therefore, we typically discourage new growers from growing Venus flytraps indoors or in terrariums.
Challenges of growing Venus flytraps in a terrarium
A terrarium creates many more problems for Venus flytraps than the few benefits it might provide. When growing outdoors the wind blows mold spores away. The rain carries mold spores, bacteria, and other nasties away. The UV light of the sun radiates mold, bacteria, and other pathogens that might otherwise take hold and make your Venus flytrap very sick.
As compared to growing outdoors, the lack of good air movement and lack of strong UV light results in a near-perfect breeding ground for mold and other diseases. It is exceptionally common to see Venus flytraps growing in terrariums succumb to crown rot.
Some of the challenges of terrarium growing can be combated with fans and very good lighting. However, growing Venus flytraps and other carnivorous plants in a terrarium it is much more work for the grower. Any problems that start to take hold in a terrarium will escalate quickly. Thus, it is vitally important to keep a close watch on plants in a terrarium and take corrective action as soon as a problem is identified.
Growing plants in a terrarium is also more expensive. This is both in terms of having to buy a terrarium and purchase good lighting — more on this below. The growing conditions Venus flytraps experience in a terrarium will never be as good as conditions as provided by growing them outdoors.
The drainage problem
Providing good drainage in a terrarium setting is also typically very challenging to achieve but is a requirement for growing Venus flytraps. Terrariums typically lack the ability to allow water to run out the bottom of the growing container. This results in minerals accumulating. These minerals will eventually reach levels that are toxic to Venus flytraps and other carnivorous plants.
Giving Venus flytraps enough light in a terrarium
Providing sufficiently strong light when growing indoors has historically been very challenging. As you’ve hopefully already read or are aware of, Venus flytraps need a lot of strong light. Ideally, a Venus flytrap will receive four or more hours of direct sunlight. This amount of light will let them be at their healthiest. Any less light than that will leave them weakened and susceptible to disease. Additionally, they will grow much more slowly without strong lighting.
In recent years, the lighting options available have dramatically improved. There are many very good, full-spectrum LED lighting options. These recent lighting improvements make indoor growing or terrarium growing much easier than it has been in the past. However, even the best artificial lighting is not as good as natural sunlight. Natural sunlight has strong enough UV light in the best color spectrum.
Given all of the factors listed above, we typically discourage using terrariums for Venus flytraps. This is particularly true for those people new to growing carnivorous plants. Again, the challenges terrariums present far outweigh any benefit they provide. Do the easy thing and grow your Venus flytraps outside in full sun and in the open air!