This article supplements a larger feature in the 2026 Spring Planning Issue of Northern Gardener magazine. Read it here!

A terrarium is more than a cute decoration—its a tiny, self-contained ecosystem that brings a pocket of nature indoors. I like to see people tend one for the pure sake of getting up close and personal with the cycle of plant life. Here are some of my favorite pointers to help both beginners and seasoned plant enthusiasts create thriving glass gardens.

Know Your History

Terrariums have a rich history dating back to Victorian England. Dr. Nathaniel Bagshaw Ward discovered that a fern could sprout inside a sealed jar, giving birth to the “Wardian case.” These early glass gardens protected plants from urban pollution and sparked indoor gardening trends that continue today.

They experienced a resurgence in the 1970s, as did all houseplants, and when Covid took hold and we cocooned, people realized again how magical they are. Modern terrariums are easier to care for but follow the same principle of Dr. Ward: moisture cycling, proper light, and thoughtful plant selection are key.

Choosing the Right Container

Glass is ideal, though acrylic works well too. Look for a container that lets light in while maintaining a contained environment. Closed or nearly closed containers retain humidity, creating a rainforest-like atmosphere that low-light plants thrive in.

Cylindrical or bulbous shapes with smaller openings are perfect for self-contained ecosystems, but beginners may prefer a wider mouth for easier planting. Always wash your container thoroughly before use, and consider adding a lid to help maintain humidity if you have a wide-open top to your piece.

Light and Watering Essentials

Terrariums do best in bright but indirect light. Early morning or late afternoon sun is fine, but midday light through glass can scorch plants and create excess condensation. Closed terrariums often need occasional additional watering; a small supplement, about a quarter cup a month, is usually sufficient.

Monitor condensation levels: a light mist is perfect, but heavy droplets running down the glass indicate an overly moist environment. When you plant your terrarium, water initially to the point that a little excess pools in the drainage layer.

Plant Selection Tips

Low-to-medium light tolerant plants make the best terrarium residents. Moss, ferns, baby’s tears, peperomia, and hypoestes thrive in enclosed ecosystems and are a few of my favorites. See photos for more examples.

Orchids can also be added for a dramatic effect, nestled into moss or orchid bark, though they don’t do well as long-term tenants. Start with smaller plants to avoid overcrowding and prune roots gently – about 1/3 of the root ball – to slow growth. You want healthy plants but keeping their size in check is a big part of success. All the fertilization happens in the ecosystem, so no additional feeding is needed or recommended.

Maintenance and Enjoyment

Even low-maintenance terrariums require occasional care: pruning, plant swapping, and monitoring water levels keep the garden attractive. Beyond aesthetics, terrariums offer a meditative experience, allowing you to slow down and observe natural cycles on a small scale.

Extra Tip: Consider adding a miniature figurine, driftwood, or decorative stone to personalize your terrarium. These small touches make your glass garden uniquely yours without interfering with its ecosystem. I stay more natural in my embellishments, but here is your chance to express yourself.

Terrariums are miniature worlds of beauty, science, and mindfulness. With the right container, plants, and care, your glass garden can thrive for years, offering both visual delight and a tiny retreat into nature right under your nose.

Eric Johnson is a longtime contributor to Northern Gardener, blogger and lifelong gardener in Roseville, Minn.

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Photo credit: Eric Johnson.