How to Make a Small Biosphere in a Jar

Many people use large jars for all sorts of storage purposes, but this project involves using a large wide mouthed jar for a purpose most people have never contemplated which is making a small biosphere. This project is great for keeping children occupied, teaching them about nature and plant life cycles or even for making a science fair entry.

You will need to procure a wide-mouthed jar with a lid, mason jars work very well for this project. In addition to the jar and lid you will need: pebbles, charcoal chips, similar plants, along with damp and sterilized potting soil. You may also use optional items like pretty seashells, stones or crystals.

Begin by thoroughly cleaning the jar and lid with hot, soapy water. It is not necessary to allow the jar to dry before use, however I recommend doing so because a wet jar can possibly turn the damp soil you add to it into muddy streaks on the side of the jar.

Next you will need to put some pebbles and charcoal chips in the bottom of the jar, enough to fill the jar a 1/2 to 1 inch depending on the size of the jar you choose to use. Next add two to three cups of damp, sterilized, potting soil. This project calls for sterilized soil because the un-sterilized variety could contaminate the biosphere with insects or other organisms present in the soil.

After you have added the layers of pebbles, charcoal and damp soil you will be ready to add plants to the biosphere. It is important to choose plants that will thrive in the same conditions, such as ones that both do well with moderate light. You can choose plants that call for almost any kind of conditions provided all of the plants call for the same or similar conditions. Otherwise you will end up with some plants that thrive and others that either fail to thrive or even die.

After you have chosen your plants, plant them in the biosphere. Plant them deep enough in the soil that they are supported by it and can remain upright after you let go of them. However, don't plant them so deep that the bottom of them ends up in the pebbles and charcoal layer.

Once you have planted the plants you are nearly finished. All that is left is adding enough water to make the biosphere humid. After you have added the initial water, you will not need to do so again like you would with most plants. The biosphere will, when properly built, will continuously cycle water from the plants to the pebble and charcoal layer. The charcoal in the first layer will naturally filter the water.

Now, if you wish, you may add pretty objects such as shells, stones and crystals. Using stones or other objects that are naturally found near the plants you choose to add to the biosphere will probably earn some bonus points if the biosphere is entered in a science fair. After adding the optional items tightly cap the jar and place it in dim light (either artificial or sunlight) for several days. After this period it is okay to display the biosphere in bright artificial light, however you must keep it out of direct sunlight or the water in the biosphere will evaporate and you will have to add more.