Terrarium Perennials

Trees

• Several tree seedling species grow inside terrariums. Terrarium trees grow best in open terrariums. Species growing well inside terrariums include the Norfolk Island pine (Araucaria heterophylla), a fast-growing evergreen with dark, needlelike foliage, curved trunks and twisted branches. The Canadian hemlock (Tsuga canadensis) grows well in open-topped terrariums. This conifer has arching, slightly pendulous branches covered with aromatic green needles. The Eastern red cedar (Juniperus virginiana) has dense, awl-shaped, green foliage and produces blue berries. Other trees for terrariums include white pines (Pinus strobus) and yews (Taxus canadensis).

Ferns

• Many perennial ferns thrive in humid environments, making them good choices for terrariums. The maidenhair fern (Adiantum raddianum) grows in clusters of feathery, light-green foliage. It prefers shady sites with moist soil. Ferns from the Pteris genus grow well in terrariums. Options include the ostrich fern (P. nodulosa), a deciduous plant with plumelike, arching fronds that grows in a vase shape. This easy-to-grow fern thrives in shady, moist sites. The button fern (Pellaea rotundifolia) grows naturally in subtropical climates, making it an appropriate terrarium plant. It thrives in bright shade and fertile, acidic soil.

Groundcovers

• Several perennial groundcovers, low-growing plants that spread wider than they grow tall, thrive in moist, humid terrarium environments. Species include wintergreen (Gaultheria procumbens), which grows from 3 to 5 inches tall. This evergreen has aromatic, glossy foliage tinted with shades of maroon and purple. It blooms with pink flowers in spring, followed by edible, red berries. Wild strawberry (Fragaria virginiana) also grows well in terrariums. This low-growing perennial spreads quickly and produces flat, white flowers followed by edible fruits.

Flowers

• Some perennial flowers thrive in the moist, humid terrarium ecosystem. These include wildflowers in the Saxifraga genus. These small perennials have hairy, thin stems and broad, green foliage with maroon undersides. Early saxifrage (S. virginiensis) blooms with small, white and yellow flowers in late spring, while Michaeux's saxifrage (S. michauxii) flowers in summer. Partridge berries (Mitchella repens) grow to 6 inches tall and bloom with white flowers from late spring through early summer. They have dark foliage and produce red berries.