Hymenophyllum nephrophyllum, the kidney fern, is a filmy fern species native to New Zealand. It commonly grows on the forest floor of open native bush. Individual kidney-shaped fronds stand about 5–10 cm tall. In hot weather they shrivel up to conserve moisture, but open up again when the wet returns. This species has very thin fronds which are only four to six cells in thickness. In the Māori language they are also called raurenga. A specific example of occurrence of H. nephrophyllum is within forested areas of Westland, New Zealand, where it occurs with other fern species including crown fern, Blechnum discolor.
Kidney fern typically has good disease resistance and faces relatively few insect pests. Its care is considered difficult because it needs a moist environment and frequent watering. However, the roots can rot if it is overwatered and the surroundings lack good ventilation. Kidney fern is suitable for people with some growing experience, as most people can keep it alive for a certain period. Still, it may struggle to thrive and its leaves can dry out and become less healthy over time.
How to keep Hymenophyllum Nephrophyllum.
Light
The kidney fern thrives in settings such as forest understories or rocky terrains that naturally provide shade. It favours Full Shade for sunlight conditions, although it's also capable of withstanding Partial Sun.
Water
The kidney fern flourishes in humid, shady environments, preferring consistent moisture yet possessing a moderate tolerance for drought. It should be watered twice a week and also benefits from occasional misting. As an epiphytic plant, it is well-suited for indoor growth, where conditions can mimic its natural habitat, supporting its delicate fronds.
Pruning
The kidney fern features delicate, kidney-shaped fronds and benefits greatly from pruning in early spring to encourage vigorous growth. Removing any yellowing fronds can improve airflow and reduce the risk of disease. Pruning also promotes denser foliage, enhancing the plant's overall appearance. Always sanitize your tools before use to prevent the introduction of pathogens.
Botanical profile.
- Plant Type
- Fern
- Life Cycle
- Perennial
- Genus
- Hymenophyllum
- Family
- Hymenophyllaceae
- Hardiness Zone
- 9-11
- Mature Height
- 5 cm to 15 cm
- Mature Spread
- 10 cm to 20 cm
- Leaf Color
- Dark Green
- Leaf Type
- Semi-evergreen
- Planting Time
- Spring, Summer, Autumn
- Native Area
- New Zealand
