Best Plants for Terrariums: A Comprehensive Selection Guide

Choosing the right plants is the single most important decision in terrarium creation. The wrong selection leads to failure regardless of how perfect your container or growing medium might be. This guide covers the best plant options for every type of terrarium, helping you build combinations that thrive together.

The Golden Rule of Plant Selection

Before exploring specific plants, understand the most critical principle: always choose plants with similar environmental requirements. A terrarium containing both succulents and ferns is destined to fail—one group needs dry conditions, the other requires constant humidity. One will always suffer.

This rule extends beyond just humidity. Consider light requirements, growth rates, and mature sizes. A fast-growing vine will quickly overwhelm slower companions. A plant that needs bright light won't thrive alongside shade-lovers.

Plants for Closed Terrariums

Closed terrariums maintain high humidity levels of 80-100%, making them ideal for tropical plants that would otherwise struggle in Australian homes with air conditioning or heating. These plants typically prefer indirect light and consistent moisture.

Fittonia (Nerve Plant)

Perhaps the most popular closed terrarium plant, fittonia features stunning vein patterns in white, pink, or red against green leaves. These compact plants typically grow 10-15cm tall and spread slowly, making them ideal for smaller containers. They're remarkably forgiving—if underwatered, they'll dramatically wilt but usually recover quickly once moisture returns. Fittonia prefers low to medium indirect light; too much sun bleaches the distinctive veining.

Ferns

Several fern species excel in terrarium conditions. The maidenhair fern (Adiantum) creates delicate, feathery fronds but requires consistent humidity—perfect for sealed containers. Button fern (Pellaea rotundifolia) offers round, compact foliage that stays low and spreads gently. Lemon button fern adds a subtle citrus fragrance. For larger terrariums, consider asparagus fern (not a true fern) which creates an airy, cloud-like effect.

Moss Species

Moss creates the foundation of many terrarium landscapes, providing ground cover and a lush, forest-floor aesthetic. Sheet moss (Hypnum) lays flat and creates carpets of green. Cushion moss (Leucobryum) forms rounded mounds. Java moss can attach to rocks and driftwood. Moss requires consistent moisture and moderate to low light—it will brown and crisp if conditions become too dry.

Peperomia

This diverse genus offers numerous terrarium-suitable varieties. Peperomia caperata features textured, heart-shaped leaves in green or red. Peperomia prostrata (string of turtles) creates trailing stems with turtle-shell-patterned leaves. Watermelon peperomia displays striking striped leaves. All peperomias prefer moderate indirect light and tolerate the high humidity of closed containers well.

Selaginella (Spike Moss)

Despite the common name, selaginella isn't true moss—it's more closely related to ferns. These plants create dense, feathery growth perfect for filling spaces between larger specimens. They require consistently moist conditions and will quickly brown if allowed to dry. Golden selaginella offers yellow-green foliage for colour variation.

Plants for Open Terrariums

Open terrariums suit plants that prefer drier conditions and good air circulation. These are typically easier to maintain for beginners and offer a different aesthetic—often more sculptural and minimalist than the lush tropical look of closed terrariums.

Succulents

The quintessential open terrarium plants, succulents store water in their thick leaves, tolerating the dry conditions of open containers. Echeveria species form beautiful rosettes in colours ranging from green through pink, purple, and blue-grey. Haworthia offers striped, windowed, or speckled varieties that stay compact. Sedums create trailing elements, and crassula (jade plant relatives) add structural interest.

When selecting succulents, consider growth habits. Some stretch toward light (etiolate) more easily than others—haworthias tend to maintain their form better in lower light than many echeverias.

Air Plants (Tillandsia)

Air plants don't need soil at all—they absorb moisture and nutrients through their leaves. This makes them incredibly versatile for terrarium design; they can be placed on rocks, driftwood, or simply resting on sand. They require occasional misting or soaking and good air circulation. Tillandsia ionantha turns pink when blooming, while larger species like T. xerographica make dramatic architectural statements.

Cacti

For sunny locations, small cacti can work in open terrariums. They need excellent drainage and minimal watering. Choose slow-growing varieties like mammillaria or rebutia to avoid them quickly outgrowing their space. Note that cacti require more light than most succulents—they're not suitable for dim locations.

Living Stones (Lithops)

These fascinating succulents resemble pebbles, making them perfect for desert-themed terrariums. They're extremely drought-tolerant—in fact, overwatering is their most common killer. Provide bright light and water sparingly during their active growing season (autumn in Australia). They split open to reveal new growth, creating an engaging display over time.

Plants to Avoid

Certain plants are commonly sold for terrariums but rarely succeed in these conditions. Understanding why helps you make better choices.

Polka Dot Plant (Hypoestes)

While often sold in terrarium sections, polka dot plants grow extremely fast and become leggy. They'll quickly outgrow most terrariums and require constant pruning. Better alternatives include fittonia, which offers similar colour variation with slower, more compact growth.

Croton

These colourful plants grow far too large for terrariums and are notoriously sensitive to changes in conditions. Moving them often causes leaf drop. They're better suited to regular potting.

Peace Lily

Though moisture-loving, peace lilies grow too large and need more root space than terrariums provide. They're also sensitive to the stagnant air conditions in closed containers.

Standard Roses or Flowering Plants

Most flowering plants require conditions (light, air circulation, seasonal changes) that terrariums cannot provide. Spent flowers also create maintenance issues and can encourage mould.

Sourcing Plants for Australian Terrariums

Finding suitable terrarium plants in Australia requires knowing where to look. Major nurseries typically stock common succulents and occasionally fittonia. For more diverse selections, seek out specialist nurseries focusing on indoor plants or tropicals.

Online plant communities and marketplace groups often have enthusiasts selling cuttings and divisions at reasonable prices. This can be an excellent way to obtain unusual varieties. When purchasing online, verify the seller's reputation and ensure plants are packaged properly for shipping.

Quarantine and Preparation

Before adding any new plant to your terrarium, quarantine it for at least two weeks. This allows you to observe for pests or diseases that could spread to your existing plants. Keep new arrivals in a separate location and check regularly for signs of problems.

When preparing plants for terrarium planting, gently remove old soil and inspect roots. Trim any damaged or rotting roots with clean scissors. For mosses collected from gardens, check carefully for insects or eggs hidden within the growth.

Considering Native Australian Plants

Some native Australian plants can work in terrariums, though they're less commonly used. Certain native mosses adapt well to closed terrariums. For open terrariums, small native succulents like Carpobrotus (pigface) or native violets might work in specific conditions. Research species-specific requirements carefully, as native plants often have particular needs.

Creating Visual Interest

Beyond ensuring compatibility, consider how plants work together visually. Include plants of varying heights—taller specimens at the back or centre, shorter ones toward the front and edges. Mix textures: smooth succulent leaves against spiky air plants, or delicate fern fronds against dense moss carpets. Consider colour too—green comes in countless shades, and many plants offer silver, pink, purple, or variegated foliage.

Growth and Evolution

Remember that terrariums are living systems that change over time. Some plants may grow larger than expected; others might not thrive despite your best efforts. Be prepared to prune, remove, and replace plants as your terrarium evolves. This ongoing process is part of the joy of terrarium keeping—each adjustment teaches you more about what works in your specific conditions.

For more guidance on creating thriving terrariums, explore our beginner's guide or learn about common mistakes to avoid.