How to Make a Terrarium in a Jar with Your Kids

Create a magical mini garden in a jar with this simple terrarium project that brings nature indoors for the whole family.

1. Gather Your Materials. You'll need a clear glass jar with a wide mouth (mason jars work perfectly), small pebbles or aquarium gravel for drainage, activated charcoal (available at pet stores), potting soil, small plants that thrive in humidity like ferns or baby tears, and decorative elements like small figurines or colorful stones. If you want a closed terrarium, make sure your jar has a lid. For an open terrarium, any wide-mouth jar will do.
2. Create the Foundation Layers. Start by adding a layer of pebbles about one inch deep at the bottom of your jar — this prevents water from sitting around plant roots. Next, sprinkle a thin layer of activated charcoal over the pebbles to keep the terrarium fresh and prevent odors. Then add about two inches of potting soil, creating small hills and valleys to make it interesting. Let your kids help pour and smooth each layer — they love seeing the colorful stripes form inside the jar.
3. Plant Your Mini Garden. Remove your plants from their containers and gently shake off excess soil from the roots. Use your finger or a spoon to create small holes in your terrarium soil, then carefully place each plant inside. Pat the soil gently around the roots to secure them. Space plants so they have room to grow — overcrowding leads to problems later. If your jar opening is narrow, use tweezers or chopsticks to position plants precisely.
4. Add Decorative Touches. This is where kids really shine — let them place small decorative stones, tiny figurines, or pieces of driftwood to create their own little world. Keep decorations small and don't overcrowd the space. Some families like to create themes like fairy gardens, dinosaur worlds, or beach scenes. Just make sure decorative items won't harm plants or hold onto moisture that could cause problems.
5. Water and Seal Your Terrarium. Lightly mist the soil and plants with a spray bottle — the soil should be damp but not soggy. For closed terrariums, place the lid on top. You should see some condensation on the glass within a day or two, which means your mini ecosystem is working. If you see too much condensation that blocks your view, remove the lid for a few hours to let excess moisture escape, then replace it.
6. Care for Your Terrarium. Place your terrarium in bright, indirect light — direct sunlight will overheat it. Closed terrariums rarely need watering since they recycle their own moisture. Open terrariums need light misting when the soil looks dry, usually every week or two. Trim any dead leaves promptly and remove them from the jar to prevent mold. If plants outgrow the space, carefully transplant them to regular pots.