It is true that terrariums require very little care. They often allow the most novice of gardener to grow a green thumb. It has been said that terrariums actually thrive on neglect and this is very close to being true. However because a terrarium is not actually an inanimate object there are several areas of care that need attention.


Terrariums are often referred to as miniature greenhouses. Because of their design, terrariums do have many greenhouse-like characteristics. Because of this, terrariums should never be placed in direct sunlight. Direct sunlight can cause the terrariums internal temperature to become too high.

This high temperature and the greenhouse like conditions will kill the plants in the terrarium. The terrarium should be kept in a north or northeast corner where sufficient light will be obtained but direct sunlight will not harm the plants.

There is an exception however. If your terrarium contains plants that will flower, such as African violets or orchids, your terrarium will require some direct sunlight. Place terrariums with flowering plants in an east window and remove the cover, allowing the direct sunlight to enter the terrarium.

If the terrarium is placed in a location where there is little light, artificial light can be added. A simple, 100 watt bulb placed close to the terrarium will help provide sufficient light. alternatively, fluorescent tubes can be placed over the terrarium. This is also a helpful solution.

When artificial light is needed, it is best if it is provided for up to 16 to 18 hours a day. Plants that receive light from a window will gradually grow toward that window. This will take away from the attractive value of the terrarium. there is an easy solution to this problem. Turning the terrarium occasionally will keep the plants growing in a normal fashion.

Trimming and Pruning: 

As stated before, terrariums are not inanimate objects. If successful, your terrarium will grow, producing beautiful plant arrangements. however, because a terrarium has limited space for the plants to grow, it is necessary to inhibit plant growth. this can be done by carefully trimming and pruning the plants in your terrarium.

Most plants in your terrarium can be pruned by removing their growing tips. This trimming will also promote the growth of side shoots and increases the bushiness of your plants, adding beauty to your arrangement.

It is also important to trim and remove any part of the plants that show signs of disease or fungus. Always remove any parts of the plants that you trim or prune. Never leave dead leaves or any dead plant parts in the bottom of your terrarium.


When watering your terrarium, the most important thing is that you never over water. It is better for your terrarium to be a little too dry than to be too moist. Over watering is the number one problem in terrariums. It is not uncommon for a terrarium not to need watering for 4 to 6 months.

Never allow standing water to remain in the bottom of the terrarium. This water will cause root rot and the development of fungus on the plants.

Always monitor the soil and look at the plants. Always water cautiously and only when the plants are dry. A terrarium recycles water by producing condensation on its walls. This happens during periods of photosynthesis and increased heat in the room. The condensation then drips back into the soil and is recycled back into the system.

Watering should only be done when there is no condensation on the terrarium walls. If there is excess water in the bottom of the terrarium, use a rolled-up paper towel to absorb the water. You can also place the terrarium in an area where there is more light. This will speed up the evaporation of the excess water.

It is also important not to replace the cover until wet foliage has dried. The best way to control the watering of your terrarium is to observe the plants. Dry, brown or brittle leaves and the lack of plant growth indicate the lack of water in your terrarium.


Generally, it is not advisable to fertilize your terrarium. This is because fertilizer may cause a build-up of soluble salts in the soil. Fertilizer also causes another problem in a terrarium. It will cause your plants to grow too fast. The plants will outgrow the terrarium and you will not be able to trim them effectively.

However if after the first year, the plants in the terrarium appear yellowish or just lack vigor and there are no other apparent problems, a light fertilization may be necessary. If you need to fertilize your terrarium, use a water-soluble houseplant fertilizer. The dosage used should be about 1/4 of what is recommended for normal houseplants. never allow any of this fertilizer to be left on the plants.

Following these simple guidelines will ensure the success of your terrarium.

Article source:
Author, Mitch Endick.