It’s that time of the year to get dirty and grow things! But not everyone has the space or time for their own backyard garden.  With this fun activity, kids can plant their own miniature garden in an upcycled soda bottle… and all the space you need is a kitchen table! 

(Special thanks to my friends in my local MOMS Club, who came over and made terrariums with us in our backyard!)

LEARN SCIENCE VOCABULARY:

• Terrarium – an enclosed, see-through garden (Fun Fact: sometimes people keep live animals inside large terrariums… and then it is called a vivarium!).
• Transpiration – plants absorb water through their roots and release it as water vapor through pores in their leaves.
• Photosynthesis – plants use sunlight, water, and carbon dioxide to make their own ‘food’. (They also release oxygen into the air, which is why plants- especially forests– are so important to human life on Earth!)

MATERIALS NEEDED: 

• Empty, clean 2-liter bottle with cap
• Small rocks or pebbles
• Soil
• Water (It’s best to use a spray bottle to keep your terrarium at the right moisture level after it’s planted.)
• Small plants (Choose hardy plants that prefer shade or part-sun, since your terrarium will be inside. You can also plants seeds instead – if your kids have the patience to wait for them to germinate!)
• Scissors (a box cutter also comes in handy for starting the cut in your 2-liter)
• Optional materials:
  • Activated Charcoal/Carbon (you can find this in the aquarium section of pet stores or at Walmart…it’s the same stuff used in aquarium filters.)
  • Spanish moss (also called Sphagnum Moss…you can find this in the reptile section of pet stores)

HOW TO MAKE IT:

1. Cut the 2-liter bottle in half with some good adult-size scissors (or a box-cutter – definitely do this step before getting your kids involved).

   

2. Put a handful of pebbles in the bottom of the bottle (about 1 inch deep).
3. Optional: Put a thin layer of activated charcoal over the pebbles. (The charcoal acts a filter for the water, helping to clean it and keep down odors.)
4. Optional: Fluff up the moss and put a thin layer over the top of the charcoal/pebble layer. (The moss acts as a barrier between the soil and the charcoal/pebble layer…it retains moisture and keeps the soil from clogging up the pebbles.)
5. Now add the soil – about 4 inches deep.

   

6. Dig a hole in the soil for each plant and carefully place them in.  Gently pat down the soil around the roots of the plant.
   

   
7. Wet the soil slightly; not so much water that you turn your dirt to mud.  (You can also put a thin layer of moss over the soil to make it look cool.)

   

8. Place the top half of the bottle over the bottom so that it fits snugly. (You may need to make small slits in the side with your scissors so that it will slide over the bottom part.) Leave the cap on the bottle.
9. Keep your terrarium inside out of direct sunlight. Spray water into the terrarium periodically to keep it moist.  You don’t want the inside of the bottle to fog up (you will see water droplets forming inside the bottle though, which is a good thing), but you want to keep the soil from appearing dry.  (If the moisture builds up too much, take the cap off the bottle for a while to avoid mold.) Now you can watch as your plants grow and bloom inside the terrarium!  

THE SCIENCE BEHIND IT:

Your terrarium is a ‘closed system’ for water, meaning that the water you initially put on the soil will cycle through the soil/moss/charcoal/rock layer, into the plant’s roots, and out through the plant’s leaves by the process of TRANSPIRATION.  You will see water vapor condensing as droplets on the inside of the bottle, and this water will fall back onto the soil to start the cycle again!  This is why your terrarium is so low-maintenance (for those of you with a ‘brown thumb’) and you won’t need to water it very much!

Your plants will use sunlight, water and carbon dioxide in the air to create their own food through the process of PHOTOSYNTHESIS. (You may remember from school that PHOTOSYNTHESIS takes place in the green chloroplast cells in the plant’s leaves.). Plants release oxygen through their leaves, which is why they are so important to keep around!

NOTE: Keep them out of direct sunlight, because the bottle will act as a greenhouse and too much heat will wilt the plants.