Terrarium Building Guide: How To Set Up A Terrarium

Miniature Landscape Inside A Glass Container
(Image credit: amy gizienski)

There's something magical about a terrarium, a miniature landscape tucked into a glass container. Building a terrarium is easy, inexpensive, and allows plenty of opportunities for creativity and self-expression for gardeners of all ages.

Terrarium Supplies

Nearly any clear glass container is suitable, and you might find the perfect container at your local thrift shop. For example, look for a goldfish bowl, a one-gallon jar, or an old aquarium. A one-quart canning jar or brandy snifter is large enough for a small landscape with one or two plants. You don't need a lot of potting soil, but it should be lightweight and porous. A good-quality, peat-based commercial potting mix works well. Even better, add a small handful of sand to improve drainage. You'll also need enough gravel or pebbles to make a layer in the bottom of the container, along with a small amount of activated charcoal to keep the terrarium fresh.

Terrarium Building Guide

Learning how to set up a terrarium is simple. Begin by arranging 1 to 2 inches (2.5-5 cm.) of gravel or pebbles in the bottom of the container, which provides a place for excess water to drain. Remember that terrariums don't have drainage holes and soggy soil is likely to kill your plants. Top the gravel with a thin layer of activated charcoal to keep the terrarium air fresh and sweet-smelling. Add a few inches (8 cm.) of potting soil, enough to accommodate the root balls of the small plants. You may want to vary the depth to create interest. For example, it works well to mound the potting mix at the back of the container, especially if the miniature landscape will be viewed from the front. At this point, your terrarium is ready to plant. Arrange the terrarium with tall plants in the back and shorter plants at the front. Look for slow-growing plants in a variety of sizes and textures. Include one plant that adds a splash of color. Be sure to allow space for air circulation between plants.

Terrarium Ideas

Don't be afraid to experiment and have fun with your terrarium. For instance, arrange interesting rocks, bark, or seashells amidst the plants, or create a miniature world with small animals or figurines. A layer of moss pressed on the soil between the plants creates a velvety groundcover for the terrarium. Terrarium environments are a great way to enjoy plants year-round. This easy DIY gift idea is one of many projects featured in our latest eBook, Bring Your Garden Indoors: 13 DIY Projects for the Fall and Winter. Learn how downloading our latest eBook can help your neighbors in need by clicking here.

Mary H. Dyer

A Credentialed Garden Writer, Mary H. Dyer was with Gardening Know How in the very beginning, publishing articles as early as 2007.