Kangaroo ferns (Microsorum pustulatum or Phymatosorus pustulatus) are captivating plants known for their distinctive appearance. What many people call “roots” are actually creeping, visible structures that define much of the plant’s character. Understanding these structures is fundamental to providing optimal care.
Unique Characteristics of Kangaroo Fern Roots
Kangaroo fern ‘roots’ are actually rhizomes, specialized stems that grow horizontally. Unlike true roots, which anchor the plant and absorb nutrients, rhizomes provide stability and contain nodes for new fronds and adventitious roots.
Rhizomes are often fuzzy or scaly; their surface growth allows them to cling to surfaces like tree trunks or rocks in their native habitats.
In native environments like New Zealand and Australia, kangaroo ferns are often epiphytic or lithophytic, growing on other plants or rocks. Their creeping rhizomes cling to these surfaces, absorbing moisture and nutrients from the air and decaying organic matter.
Essential Care for Healthy Roots
Kangaroo fern rhizomes require a correct, well-draining, airy potting medium that prevents waterlogging. Suitable mixes include orchid bark, perlite, and peat moss or coco coir. The ideal soil pH is slightly acidic to neutral (6.0-7.0).
Water consistently, keeping the soil moist but never soggy, as excessive moisture leads to issues. Allow the top inch or two of the potting mix to dry out slightly between waterings, and ensure adequate drainage holes.
Shallow, wide pots are suitable for spreading rhizomes, allowing them to spread across the surface. Terracotta pots are beneficial, promoting better air circulation.
Adequate light and humidity contribute to the fern’s vigor and rhizome development. Bright, indirect light encourages healthy frond growth. Maintaining 50% or higher humidity benefits the plant by reducing moisture loss.
Managing Root Growth and Propagation
Kangaroo fern rhizomes have a creeping habit. As they spread, they grow over pot edges or across the growing medium. They can hang gracefully, or be redirected onto the soil to encourage further rooting.
Kangaroo ferns are easily propagated directly from their rhizomes. This effective method simplifies creating new plants from a mature specimen by division.
To propagate, follow these steps:
Select a healthy rhizome section with at least two or three fronds.
Using clean, sharp scissors or a knife, cut the section from the parent plant, ensuring it includes rhizome, roots, and fronds.
Place the severed section directly on top of a fresh, moist potting mix.
Do not bury the rhizome; allow it to sit on the surface, making contact with the moist substrate.
Over time, the rhizome will send out new roots into the potting mix, establishing a new plant. Consistent moisture and ambient humidity encourage faster rooting.
Addressing Common Root Issues
Root rot, caused by overwatering, is a frequent problem for kangaroo fern rhizomes. Soggy potting mix deprives rhizomes of oxygen, leading to decay. Symptoms include mushy, dark brown, or black rhizomes. Address this by improving drainage, adjusting watering, and repotting into fresh, well-draining substrate.
Insufficient watering or very low humidity can lead to drying and crispy rhizomes. When the plant does not receive enough moisture, rhizomes can shrivel, become brittle, and turn light brown or gray. Provide consistent watering and increased humidity.
Pests can sometimes affect rhizomes. Inspect the plant regularly for infestations. If found, treat by wiping with a cotton swab dipped in rubbing alcohol or by applying an insecticidal soap.