Parablechnum cordatum (synonyms Blechnum cordatum, Blechnum chilense), the Chilean hard fern or costilla de vaca (Chilean Spanish for "cow's rib"), is a fern of the family Blechnaceae, native to Chile. It is also found in neighboring areas of Argentina and the Juan Fernández Islands. It grows to 0.9–1.8 m (2 ft 11 in – 5 ft 11 in), often developing a trunk-like appearance over time. The fertile fronds are more erect, with narrower pinnae, than the infertile ones.This plant has gained the Royal Horticultural Society's Award of Garden Merit.
Parablechnum cordatum typically has strong resistance to disease and is affected by relatively few insect pests. Its care is considered challenging because it requires a consistently moist environment and frequent watering. However, the roots are vulnerable to rotting if overwatered and the air circulation is poor. Parablechnum cordatum is suitable for people with some growing experience, as most can keep it alive for a certain period. Still, it may struggle to thrive and its leaves can dry out and decline in health over time.
How to keep Blechnum Cordatum.
Light
Parablechnum cordatum comes from habitats such as forest understories or rocky areas that provide natural shade. It prefers Full Shade but can tolerate Partial Sun.
Temperature
Parablechnum cordatum grows in forest thickets. It is very sensitive to temperature and humidity; high heat, dry conditions, and strong sunlight all make the plant uncomfortable. In summer it needs adequate shading and a humid environment. Generally it does not need special care in winter, but prolonged winter drought can still kill the plant.
Botanical profile.
Other names.
