Blechnum penna-marina
Notify MeBlechnum penna-marina, commonly known as alpine water fern, is a low-growing, mat-forming fern native to New Zealand. It features finely divided, leathery fronds that emerge bronze or reddish and mature to a glossy deep green, creating a soft yet structured carpet in shaded areas. Its evergreen habit and spreading form make it ideal for groundcover.
A natural choice for native, alpine, woodland, and shaded rock gardens, it works well between pavers, along paths, or beneath trees where a delicate understorey is desired.
Prefers partial to full shade and moist, well-draining soil with plenty of organic matter. Tolerates cool temperatures and light frosts. Space 30–40 cm apart to encourage dense ground coverage.
Mature size reaches 10–20 cm tall and spreads up to 60 cm wide.
Trimming: Requires very little maintenance. Remove old, withered, or damaged fronds at the base to tidy the plant and stimulate new growth. No regular pruning is necessary.
Deadheading: Not applicable.
Fertilising: In spring, apply a light dressing of balanced, slow-release fertiliser, particularly if growing in nutrient-poor soil. An annual mulch with leaf litter or compost helps mimic natural alpine conditions and promotes healthy growth.
Watering: Keep soil evenly moist, especially during dry periods. Blechnum penna-marina prefers cool, damp, well-drained environments and does not tolerate drought. Mulch helps retain moisture and protect the shallow root system.
Pest Control: Typically pest-free. In damp conditions, slugs or snails may occasionally damage young fronds—use organic methods such as traps or hand-picking if needed.
Disease Management: Rarely troubled by disease. Ensure good drainage to prevent root rot, and remove any decaying or discoloured fronds to maintain overall plant health.
Enjoy complimentary delivery anywhere in mainland New Zealand when you purchase plants worth $250 or more*.
For orders below $250, the following flat-rate delivery charges are applicable:
- Urban delivery within mainland New Zealand: $19.95
- Rural delivery within mainland New Zealand: $39.95
- Waiheke, Chatham and Great Barrier Islands: Please contact us for shipping options.
We aim to have all orders shipped within 14 days from the order date, unless a different shipping date is specified alongside a product.
