Terrarium Building with Students

Pseudo spring has us in the mood for green, but mother nature has another idea! Therefore...we're making our own little piece of spring...in a bottle. 

Terrarium building is fun and is a great opportunity to teach about ecosystems and the water cycle. I built terrariums with my Ranch boys (where I volunteer) and with my own boys at home.

Terrariums are simple to build, and if you think about it ahead of time, you can reuse, and upcycle supplies that would otherwise be thrown away. I had the cook at school save all the large glass jars from items in bulk. Mine were primarily olive and hot peppers jars! 

Terrarium Building Supplies

• Large glass (or plastic) container with loose fitting lid
• Potting soil mix
• Gravel (sterlized)
• Charcoal 
• Small houseplants
• Newspaper

• Clean, soft, dry, paint brushes
• Funnel
• Water bottle
• Misc. decorations; small rocks, sticks, colored glass, or shells.

Terrarium Tool-Building Supplies

• Cork
• Plastic spoon
• Wooden skewers
• Tape
• Glue gun and hot glue
  

1.     First, you’ll need to assembly your supplies, including the plants you’d like to put into your terrarium. 

2.     We found that making some specialized tools was incredibly helpful when building a terrarium. Extending a plastic spoon by taping it to wooden skewers worked well when we were trying to place the soil in a specific spot around the plants. And gluing a poker chip to a cork that was skewered worked wonders when we needed to tamp down the soil after placing the plants into the soil.

3.     Using your funnel, pour a layer of pebbles in the bottom of the jar. If you are working with students, remind them that the rocks may break the glass if the pebbles are tossed in to quickly. These pebbles provide drainage and air pockets for the roots of the plants. I sanitized my rocks by washing them, then placing them on a cookie sheet and baking them @300^o for 15 minutes. Although, I’m not sure that is necessary.

4.     On top of the pebbles place a thin layer of charcoal. This absorbs odors and keeps the soil fresh. 

5.     Now for the art part of the lesson. I had students choose their plants based on color, texture, and height. We talked a bit about composition, how a still-life (essentially what we are doing here) looks best groups of odd numbers and at different heights. Instead of choosing plants that all have the same colors or textures, it’s aesthetically pleasing to have variety as long as they don’t clash.

6.     Next, you’ll add a thin layer of soil. Compare your plant heights’ to the jar in order to judge how high the soil line should be when completed. Depending on how many plants you want, we found it easiest to place the plant(s) in first and add the soil in around it, then put all the soil in, then dig a whole.

7.     When removing plants from their containers, straddle the base of the plant with your pointer finger and middle finger near the surface of the plant’s container (see photo below). Then flip the plant upside down and slowly remove the pot. You may need to tap it a few tips to get it loose. If the roots are clearly visible and were circled at the bottom of the pot, the plant was pot-bound. You may want to take a scissors and cut away some of the extra roots. Don’t worry, the plant will be fine!

8.     Now you’re ready to put the plant into the glass terrarium. Its ok to handle the plants by their foliage, as long as you’re grasping most of the leaves, and not stressing the plant by lifting it by a single leaf/leaflet. Drop your plants into the terrarium and turn them so the nicest side faces out.

9.     Now, use your terrarium tools to fill in soil between the plants. Tamp the soil as you go. Some of my students made their tool to have a spoon on one end, and the tamper on the other. Very efficient!

10. Once the plants are tucked in and the soil is level, you may need to clean the leaves a bit. Use a small, clean, dry paintbrush to remove any soil that may have landed on the leaves of our plants. Be sure to do this BEFORE you add water or you’ll have a muddy mess on your hands.

11. If you want, you can now add in your decorations. Remember, less is more, and natural elements look better then artificial elements.

12. Last, spray water into your terrarium being sure to saturate the soil; however, you don’t want it to be so wet that there is standing water on the surface. It’s a good idea to spray the leave a bit as well. Its importance to place the lid on securely, yet loosely, to allow some air to get in. And you’re done!

Caring for Your Terrarium

Place the terrarium indoors near a window, but not in direct sunlight. Train your students and kids to handle the terrarium from the bottom, and to never carry it by the lid. The terrarium will be heavy, and the lid is not on as tightly as items they might pull from a refrigerator.  They wouldn’t want all their hard work to be wasted!

Terrariums, if set up properly will be self-sustaining, as the moisture in the container will move through the entire water cycle; evaporation, condensation, and precipitation keeping your plants happy for life! Look for the sign water droplets and a bit of fog inside of the terrarium walls. However, the first few days are critical. Look for signs that the plant has too much, or not enough moisture.

Check Plants for Signs of Stress: Tips for trouble shooting your terrarium

Leaves are turning black: Too much water. Remove the lid overnight and allow some of the water to evaporate out of the container.

Leaves are turning brown on the edges and look “crunchy.” Not enough water. Add a few more sprays of water, and make sure the lid stays on securely, but too tight.

Sometimes the plants you’ve chosen to live together inside the terrarium don’t get along! If one of the plants isn’t doing well, no matter what you do, you may need to replace it with another type of plant.

If after two weeks, your plants look healthy, and there’s evidence of the water cycle happening within, you shouldn’t have to ever water it again!  Some plants will absolutely love their new environment and may grow filling the inside of the terrarium with its leaves. This is just fine. However, if you are not happy with how it looks, you may choose to open the lid and pinch back the leaves until you are pleased with it again. But because you’ve removed the lid, you’ll need to pay extra attention to the terrarium for a couple of weeks, to be sure the water cycle is self-sustaining again.

Making a Pretty Lid for Your Terrarium

While the metal lids to our glass terrariums were functional, they were not pretty. You could add ribbon to the edge of the lid or even spray-paint the lid to match your décor.  Since we were donating our terrariums to a charity auction, I choose to print directions on how to care for the terrariums, and use that to cover the lid.  I printed it on lightly colored scrapbook paper and then glued it to the lids. If you’d like to use my template, you get a free copy here.  

Some terrariums have been known to live happily for 40 years. May yours have a long and happy life!