2-Liter Terrarium

2-Liter Terrarium

This activity allows children to practice
recycling and learn more about ecology,
environmental degradation, and the
scientific process.

Terrariums are miniature, self-contained
eco-systems. Once created, these closed environments can go for months unattended without even adding water. Moisture in the Terrarium evaporates from the soil and plant leaves, then condenses on the Terrarium roof and walls. The condensed water then falls down and re-moistens the soil in a continual closed loop process. As long as the top is sealed, this process will continue for months, perhaps even years. Terrariums are fun to create and observe, and make a perfect project for Earth Day celebrations!

Safety Warning: Adult supervision is required.

What You Will Need:

• Two Clear 2-Liter Plastic Soda Bottles
• Instructions for cutting the bottles
• Handful of Gravel or Small Rocks
• Potting Soil
• Plant Seed

What You Do:

• Carefully peel the label off your bottles and wash them thoroughly.
• With the help of an adult, cut one of the bottles approximately 4" up from the base of the bottle — this forms the base for your terrarium. (Download the instructions for cutting the bottles from the link above).
• Again, having an adult help, cut the second bottle approximately 8-10" up from the base of the bottle — this forms the top cover for your terrarium, and will be placed over the bottom portion.
• Use a scissor to cut four small slits, evenly spaced, around the open end of the taller bottle. The slits are used to hold the top of the terrarium onto the bottom part of the terrarium.
• Place a handful of gravel or small rocks in the bottom portion of the terrarium — this provides drainage for your plants. We recommend a 1/2" to 1" thick layer of gravel for best drainage.
• Add a layer of Sphagnum Moss. This serves to keep soil from seeping into the drainage layer. This step is optional.
• Cover the gravel with potting soil to within about 1/2" from the top of the bottle base.
• Plant seeds (or small plants) into the potting soil and water thoroughly.
• Place the top portion of the terrarium onto the bottom portion using the slits to hold the top in place.
• Put your terrarium in a sunny window in indirect sunlight and observe the changes. (Make sure to keep the terrarium out of direct sunlight. The direct sunlight can cause the temperature in the terrarium to be too high for your plants.)
• Once your terrarium has started to grow, only add water when necessary. Moisture from the terrarium should condense on the inside of the terrarium top and provide the necessary water.
• Make sure to keep your terrarium covered. It should remain self-contained for months or even more than a year.

Plant Recommendations:

• Slow-growing plants work best in a 2-liter terrarium. You may also want to choose plants that have small leaves so they don't overtake the other plants. Ideas for plants include: Swedish Ivy, miniature Gloxinias, miniature Begonias, Pinks, or miniature African Violets.
• Because the terrarium will be moist, sub-tropical plants will thrive best.
• Select a variety of plants with contrasting colors, shape, and textures to add interest to your terrarium.