What is Asplenium?

Asplenium is a very large genus of ferns in the Aspleniaceae family. The common names of the most well known types of ferns are spleenworts, walking ferns, and bird’s nest ferns. Several of these are common houseplants, particularly the bird’s nest fern, or Asplenium nidus. This specimen is of tropical origin and grows best in warm, humid environments, although many individual plants survive dry, household environments.

This species of Asplenium frequently grows on trees as an epiphyte, growing up in tree branches like a Bromeliad. The sword-like leaves sprout out from a central base, forming a funnel. Water and nutrients fall into this area and nourish the plant.

When grown in a tropical or semi-tropical climate, such as Florida, the bird’s nest fern can grow to be 4 feet (1.2 m) tall and equally wide. Its leaves are bright green and crinkled, with a black line running through their middle. They can grow up to 8 inches (20 cm) wide.

As a garden plant, these herbaceous perennials can be planted in borders or as a ground cover. It is important that they not receive direct sun, or the leaves can turn yellow and stop growing. The bird’s nest fern must be kept moist. It should only be grown outside in humid areas.

This common houseplant grows best when placed in a northern exposure. During its growing season, it must be kept moist but not overly wet. Some people choose to soak it by pouring water into the funnel created by the rosette pattern of the leaves. This fern should be watered less frequently during its winter dormant period, but should not be allowed to dry out. The ideal temperature for growth is between 50 and 55°F (10 and 12.8°C) at night, and 68 to 72°F (20 to 22.2°C) during the day.

The soil should be a mix of peat moss with potting soil. A layer of charcoal should be placed at the bottom of the pot. It is possible to wire the plant to a slab of wood or to tree trunks, like some gardeners do with staghorn ferns.

One of the biggest problems with growing this species of Asplenium indoors is having enough humidity. A common way to solve this problem is to grow the plant over pebbles that have water in them. Special slotted trays can also be ordered that hold water beneath a plastic surface. Frequently misting the plants is another option to keep them healthy. Some gardeners grow these ferns in terrariums.

The plants are rarely bothered by pests. They can be troubled by snails and slugs, however, if grown outside. A single slug can devour a whole leaf.

The plants cannot be propagated by cuttings. Since they are ferns, new plants can be grown from spores. Another possibility is to divide existing clumps.

Asplenium bulbiferum is another species in this genus that is commonly grown by gardeners. It is known as the mother fern, because little plantlets grow on the ends of its leaves. This plant is easily propagated by growing those plantlets.

This type also can grow to 4 feet (1.2 m) tall and equally wide. Unlike the bird’s nest fern, the mother fern is more cold-hardy. It can tolerate temperatures down to 26°F (-3°C). It is also vulnerable to snails and slugs.