Ground Spleenwort

Cultivating Ground Spleenwort (Asplenium appendiculatum) is a rewarding endeavor for any gardener interested in New Zealand's unique flora. This species can be propagated through several methods, each requiring specific conditions to ensure healthy growth and establishment. Successful propagation depends on mimicking the plant's natural environment and providing consistent care during the early stages of development.

From Seed

Propagation from spores is often a viable method to produce a large number of Ground Spleenwort plants, though it requires patience and specific sterile conditions. Spores are typically found on the underside of mature fronds, appearing as dark sori. To collect, place a mature frond in a paper bag and allow it to dry for a few days; the spores will drop into the bag. Prepare a sterile growing medium, ideally a mix of peat and sand, and sterilize it in the microwave or oven to kill off any fungi or bacteria. Lightly sprinkle the collected spores over the surface of the moist medium in a sealed container, avoiding covering them. Maintain high humidity and indirect light, often by covering the container with a clear lid or plastic wrap. Germination can take several weeks to months, initially forming a green film known as a prothallus. Once distinct plantlets emerge from the prothalli and are large enough to handle, they can be carefully transplanted into individual pots. The key to successful spore propagation is maintaining consistent moisture and high humidity, avoiding overwatering which can lead to damping-off.

1. Collect mature spores from healthy fronds.
2. Prepare a sterile, moist growing medium in a sealed container.
3. Lightly sprinkle spores over the surface; do not cover.
4. Maintain high humidity and indirect light.
5. Germination can take several weeks to months, forming a green film (prothallus).
6. Once prothalli develop, plantlets will emerge; transplant when large enough to handle.

The key to successful spore propagation is maintaining consistent moisture and high humidity, often achieved by covering the container with a clear lid or plastic wrap. Avoid overwatering, which can lead to damping-off.

From Cuttings

While not typically propagated by stem cuttings like woody plants, Asplenium appendiculatum can be propagated through division of its rhizomes. This is a more reliable and faster method than spore propagation for home gardeners, offering a direct way to create new, genetically identical plants. Division is best performed in spring when the plant is actively growing, which minimizes stress and allows for quicker recovery.

1. Gently lift the mature fern from its growing medium.
2. Carefully separate sections of the rhizome, ensuring each section has healthy roots and a few fronds.
3. Replant the divisions into fresh, well-draining potting mix, burying the rhizome just below the surface.
4. Water thoroughly after replanting and keep the new divisions in a shaded, humid environment until they are well-established and showing signs of new growth.

Additional Methods

The most common and successful method of increasing Asplenium appendiculatum in a garden setting is through careful division of its established clumps. This not only creates new plants but also helps to rejuvenate older, denser specimens by preventing overcrowding. For larger, more mature plants, it is sometimes possible to encourage new plantlets by allowing fronds to touch moist soil or a suitable substrate, where they may root, though this is less common than direct rhizome division. Ensure minimal stress to the parent plant during any division process, providing ample water and shade immediately after to aid recovery. This method effectively maintains the genetic purity of desired specimens and allows for controlled expansion within the garden, ensuring strong, healthy clones.