A terrarium is a tiny ecosystem you can build inside a clear jar or container. It lets you watch plants, soil, water, air, and light interact in a small space. This project matters because it shows how living and nonliving parts of nature work together.
It is also a safe, colorful way to practice observing and recording science over time.
Inside a terrarium, plants use sunlight, water, and carbon dioxide to make food by photosynthesis. Water can evaporate from soil and leaves, condense on the glass, and drip back down like a mini water cycle. Pebbles help drainage, soil holds nutrients, and roots take in water.
By changing light or water carefully, students can see how an ecosystem responds.
Key Facts
- A basic terrarium has layers: pebbles, optional charcoal, soil, plants, and decorations.
- Photosynthesis: carbon dioxide + water + light energy -> glucose + oxygen.
- Plants need light, water, air, space, and nutrients to grow.
- Evaporation changes liquid water into water vapor, and condensation changes water vapor back into liquid drops.
- A closed terrarium recycles some water, while an open terrarium loses water faster.
- Good observations include date, plant height, soil moisture, water droplets, leaf color, and changes in growth.
Vocabulary
- Terrarium
- A terrarium is a small indoor garden grown in a clear container so the plants and soil can be observed.
- Ecosystem
- An ecosystem is a community of living things interacting with nonliving parts of their environment.
- Photosynthesis
- Photosynthesis is the process plants use to make sugar from carbon dioxide and water using light energy.
- Condensation
- Condensation is the process in which water vapor cools and changes into liquid water droplets.
- Drainage
- Drainage is the movement of extra water away from plant roots so the soil does not stay too soggy.
Common Mistakes to Avoid
- Adding too much water at the start is wrong because soaked soil can block air from roots and cause mold or root rot.
- Putting the terrarium in hot direct sunlight is wrong because the glass can trap heat and overheat the plants.
- Skipping the pebble layer is wrong because extra water may collect around the roots instead of draining away.
- Planting too many plants is wrong because crowded plants compete for light, water, nutrients, and space.
Practice Questions
- 1 A jar needs a pebble layer 3 cm deep and a soil layer 8 cm deep. What is the total depth of these two layers?
- 2 A student measures a plant as 6 cm tall on Monday and 9 cm tall on Friday. How many centimeters did the plant grow?
- 3 A closed terrarium has many water droplets on the inside of the glass every morning. Explain what process is causing the droplets and why this helps the terrarium ecosystem.