Gardening with kids: Making a terrarium
One of the remarkable things about a closed terrarium is that it creates its own microclimate, or atmospheric zone where the climate differs from the surrounding area. They are great learning tools for children with the benefit of also being fun to make and easy to care for.
Think of them as a living science project to do with the kids. Terrariums, like our own planet, Earth, hold in heat from the sun, the glass acting in a similar manner to Earth’s atmosphere. They can be used to show a more basic system of interactions within an ecosystem to help children understand the more complex world we live in. While there may not be animal or insect interactions, children can observe how plants compete for survival. If different types of plants are chosen they can observe how each plant competes differently for water, sunlight and nutrients. Some will grow massive root systems, while others will grow tall, large leaves to block those below them from receiving sunlight.
Terrariums are also able to demonstrate the water cycle to children. Sunlight creates heat which causes plants to release water vapour into the air (transpiration), as the water vapour leaves the plant (evaporation) it forms droplets of water on the inside of the container (condensation). As the water accumulates and temperature drops, the condensation drips (precipitation) down the walls of the terrarium into the soil for the plants to absorb; and the cycle continues to repeat itself.
Children love taking care of living things. Terrariums give them an opportunity to learn how to become responsible stewards of their garden and the earth. Because they are creating a closed ecosystem, they are ultimately responsible for their success or failure. However, if your project fails, consider where you went wrong, and just try again.
All ecosystems need the right amount of water, light, temperatures and plants that require similar care, these tips on each element should help you design your own project.
Containers: The wonderful thing about this project is you can often find inexpensive containers at second hand stores, garage sales and your own basement. We found our containers at a thrift store. Fishbowls, globes from lighting fixtures, interestingly shaped vases, tureens, cloches, lantern cloches, bell jars, apothecary jars, Wardian cases, aquariums, mason jars; all will work. Containers that do not close will still
work, however, the plants will require more frequent watering and you will not create a microclimate condition.
It is very important to wash and rinse your containers, especially if they have been used before, not only so you can see the plants inside, but also to prevent any contaminants from entering your ecosystem. If you have chosen a container with a narrow top, use chopsticks or kitchen tongs to help you place plants and ornaments.
Plants: When choosing plants it is best to select plants that require little maintenance, are slow growers and will grow well together. Classic plants choices include, but are by no means limited to, African violets, false aralias, jade plants, miniature peperomias, nerve plants, pink polka dot plants, prayer plants, small philodendrons, Swedish ivy, spider plants, other small ferns, mosses, succulents, and cacti. Humidity levels can rise quickly in a terrarium, therefore, plants that prefer shade and are tolerant of high humidity, like those from rain forests or woodlands, will do well in these environments. Because this is a closed ecosystem, be sure to remove any dead foliage and overgrown plants to prevent the introduction of rot or mold. Leaves are likely to touch the sides, but try to keep them away to prevent burning.
Environment: The bottom layer of rocks acts as a false drainage layer which prevents flooding the plant, try to have a half to two inch base of rocks (1-5 cm). Activated charcoal will help to keep the terrarium healthy in the absence of drainage holes by reducing odours, bacterial and fungal growth. Sheet moss can be used for lining the bottom of the terrarium to soak up excess water if desired. If you decide to use sheet moss be sure to wear gloves and a long-sleeved shirt to prevent fungal infection. Also, avoid adding animals to your terrarium as they can damage plants and cause disease.
Water: Enclosed terrariums should need infrequent watering and need not be soaked. Keep the soil barely moist at all times, it should be damp under the upper layer of soil when a finger is inserted into the soil. Watering will depend on the plants chosen, the location and size of the container used. Remember to only water plants and not the mosses. Get children to observe the new environment and record how often they need to water it. Since terrariums build up humidity, if yours is airtight you will need to air it out occasionally to let the water evaporate, especially if there is too much condensation in the inside or if the plants are wilting.
Light: Where you keep your terrarium will determine its success as much as watering. In order to remain low maintenance, terrariums need a location with indirect light. Since glass magnifies the effects of the sun, direct sunlight will heat the interior of the terrarium, effectively cooking the plants. They should be kept in a warm room but not near heaters, any extreme temps or changes in temp can be harmful.
This is would be a great science project or classroom project. Children can learn about how micro ecosystems work, about condensation and humidity. Terrariums are both beautiful and educational, so why not try one?
Terrariums are not only beautiful, they are super cool, fun to make and can provide children with important lessons about microclimates, nature and our planet.
I put several small succulents together in planters and added some of my other small plants to the mini greenhouse. By adding some moss around the bases of the pots, I was able to create a uniform look and a larger terrarium for us to observe.
Terrariums are not only beautiful, they are fun to make and can provide important lessons about microclimates, nature and our planet.
The boys chose narrow containers but with a little work, and the help of some tongs, we succeeded in planting and decorating a nice trio of terrariums.
An excellent tool to learn about the water cycle. Here you can see the condensation on the walls of the jars.