Make a miniature rainforest terrarium and help the environment by reusing a plastic bottle. Enclosed terrariums mimic the way a rainforest works by creating humidity and condensation that drips down and waters the plants. Use materials, such as pebbles and activated charcoal, to keep your miniature rainforest from becoming a mushy swamp, overrun with plant-killing bacteria. Use plants like asparagus ferns and nerve plants that resemble rainforest plants, but won't outgrow the bottle. Find the materials you need at home or at the pet store.
Mark a line four inches from the bottom of a plastic two-liter bottle with a permanent marker. Cut around the bottle, at this mark, with a sharp utility knife to separate it from the rest if the bottle. Be careful to cut away from yourself and exercise caution with the utility knife.
Fill the bottom of the bottle with an inch of pebbles for a drainage layer. Measure and cut a four-inch wide circle out of a screen and place it on top of the pebble layer. This will prevent the upper layers from leaching down between the pebbles.
Place a 1/4-inch layer of activated charcoal over the window screen to prevent mould and bacteria from breeding in the rainforest terrarium, thereby killing the plants. Fill the rest of the bottom of the bottle with potting soil, leaving about a quarter-inch of room from the top edge.
Plant miniature plants in the soil that resemble rainforest plants, such as mini palms, asparagus ferns, nerve plants and croton. Spray the soil around the plants to soak it, but avoid spraying the plants themselves.
Place the top half of the bottle back on and tape around the cut with clear tape. Place the bottle near a window or bright light, but not in direct sunlight, or the plants will become overheated.
Point the blade of the knife away from your body while you are cutting the plastic bottle.