By: Tommy Adams, Chelsea Connor, Amber Epps, and David Lanier
The purpose of this Instructable is to show how to make a terrarium out of an incandescent light bulb.
Newspaper or old cloth
60W incandescent light bulb (clear or powdered): reuse from your house, or purchase new bulbs.
Salt or sugar
Small rocks or pebbles: found outside, or purchased at a hardware store or local garden store.
Activated charcoal: found in your local garden or pet store.
Dirt: found outside with your plant, or purchased from a garden store.
Small terrarium plant: found outside or in your local garden store.
Sealing cork (size 6): found in hardware stores like Lowe's or Home Depot.
Cotton swab or paint brush
Needle nose pliers
Wire cutters or regular pliers
Thin screwdriver (Philips or Flat head will work)
NOTE: Never use a fluorescent light bulb for this project. The gasses they release when broken are very dangerous!
If you are using a flood light bulb, be aware that these contain mercury and extra precaution should be taken.
$8.00 - $10.00 when purchasing all materials.
Step 1: Frequently Asked Questions
What is a terrarium?
Light bulb terrariums are miniature earth enclosure ecosystems that are self-sufficient and require minimal care. (See Image #1 "Terrarium Basics" for more information).
Who invented terrariums?
Terrariums were first discovered by a London botanist, Dr. Nathaniel Ward, in 1827. At that time, the London streets were filled with air pollution that threatened to kill the plants in his garden. In an attempt to protect his plants, he put them in a closed glass jar filled with dirt, and soon Dr. Ward observed a small healthy fern growing! Since that day, he built miniature fern cases to protect his plants, which we now call terrariums. (Source:
How do they work?
Plants releases water vapor which condenses on the glass in the form of water droplets. As gravity pulls them down, they re-hydrate the soil. As the roots take up the water, the soil and micro-bacteria release carbon dioxide, which the plants re-absorbs. (See Image #2 "How Terrariums Work" to see a diagram).
What plants should I use?
Choose small plants that will fit inside your light bulb as well as plants that are humidity tolerant. Recommendations: Sphagnum, Moss Baby's Tears or Angel's Tears, Pearlwort, African Violet, Creeping Fig.
Can I have animals in a terrarium?*
Unfortunately, it is not as simple as adding your favorite animal to your terrarium. Different animals require different types of terrariums. Be sure to DO YOUR RESEARCH before deciding on adding animals! We recommend Firefly Encyclopedia of the Vivarium by David Alderton, which gives a comprehensive overview of keeping amphibians, reptiles, and insects in terrariums for beginners. It is easy to read and understand. Attention to your animal's needs is essential.
*DO NOT use animals for this project. Light bulbs are too small for animals to live inside!
Step 2: Prepare Your Work Area
You will need: newspaper or cloth, gloves, and safety eye wear. Have all other materials nearby.
- Place a layer of newspaper or a cloth on your work surface. This will collect dirt and debris that are dropped. One or two full sheets of newspaper should be sufficient.
- Put on your gloves and safety eye wear. This will protect you from any exposure to dirt and/or broken glass, if needed.
- Make sure you have all of the materials nearby. The required materials are listed in the introduction.
Step 3: Disassemble Your Light Bulb
You will need: needle nose pliers, wire cutters (or regular pliers), tweezers, sponge, salt, cotton swab, water and a flat head screwdriver. This step is one of the most difficult steps, but you should not give up. With some patience and guidance we know that you will be able to successfully disassemble the light bulb.
- Grasp the bulb by the metal base at the bottom. (NOTE: Do not hold or squeeze the glass bulb. It may break).
- Begin by crushing the electrical foot contact (black circular bottom) with your wire cutters (or regular pliers). Remove any excess pieces that remain attached. (NOTE: It is easier if you break the whole foot first and not just the top metal piece.)
- Use your flat head screwdriver to break the glass insulator that leads to the exhaust tube.
- Insert your needle nose pliers into the exhaust tube and pull out the internal filament. The flat head screwdriver can be used to clear out any pieces left inside the exhaust tube.
- Once the inside of your light bulb is clear, you can move onto the next step.
NOTE: Here's the link to watch the video if you are using the Instructables app.
Step 4: Clear Your Light Bulb
You will need: salt or sugar, sponge,cotton swab/ paint brush, and water.
- Begin by pouring a small amount of salt or sugar into the light bulb.
- Swirl the salt around. You should begin to see the white powder clearing from the inside of the bulb. Add more salt as needed.
- If there is any writing printed on the outside of your bulb, this can be removed by scrubbing with a small amount of water and a scouring pad.
Step 5: Add Small Rocks
You will need: small rocks or pebbles.
- Drop your rocks one at a time into the bottom of your bulb. If you have smaller rocks, you can insert more than one at a time.
- It is best to hold the bulb on its side and tilt it as you place the rocks inside. That way, the rocks gently slide to the bottom and do not place any stress on the glass from being dropped.
Step 6: Add Activated Charcoal
You will need: activated charcoal.
- Using the funnel, slowly pour your charcoal into the bulb until there is enough to have a small layer over the rocks at the bottom.
(REMINDER: Charcoal is important because it helps remove toxins from the soil and keeps the soil fresh.)
Step 7: Add Soil
You will need: soil, and a funnel.
- Using the funnel, pour a layer of soil until 1/3 of the entire light bulb is filled with rocks, charcoal, and soil.
Step 8: Add Your Plant
You will need: small terrarium plant, and a screwdriver.
- Separate a portion of your plant to about the size of the light bulb opening. Make sure some roots are attached to the plant.
- Place the plant on top of the opening, roots down.
- Delicately push the plant down with your screwdriver until your plant is inside the light bulb and contacting the soil.
- Adjust the plant as necessary.
Step 9: Clean Your Light Bulb
You will need: cotton swab or paint brush.
- Lightly wipe the inside of your light bulb with a cotton swab to remove excess dirt. Do so until it is clear.
Step 10: Add Water
You will need: light bulb terrarium, and water.
- Add approximately 1 tablespoon to your light bulb terrarium. This should be enough so that the soil is moist, but not too wet. Pour the described amount in and allow it to be absorbed into the soil. Add more if necessary.
Step 11: Install Cork
You will need: light bulb terrarium, and a cork.
- Gently hold your terrarium upright and insert the cork to the opening until it is tight.
Step 12: Display and Enjoy!
Above are two different methods of displaying your terrarium.
- Hung from a string
Small ring stand
These are only two of the many display options available. Don't be afraid to get creative with your display. Thank you for reading! We hope you enjoy your new light bulb terrarium. They make great gifts and decorative items!
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