Blechnum novae-zelandiae - Kiwi Hard Fern

Blechnum novae-zelandiae is a superb New Zealand fern with large arching fronds, coppery in their youth and then shiny green, with a plastic-like appearance. Provide it with an acidic, humus-rich and moist to wet, but perfectly drained, lightly shaded soil. It will work wonders in a garden with an exotic and lush atmosphere, but should be reserved for mild climates.

The New Zealand Blechnum is a fern found on riverbanks, road edges, dripping cliffs and humid undergrowth of this large island in Oceania. While it is common there, it is also endemic, meaning it is only found there. The Maori call it Kio Kio. Recent genetic studies have classified this species in a new genus, so it is sometimes now found under the name Parablechnum novae-zelandiae. It forms large spreading clumps of persistent elongated fronds, tough, born coppery orange (sometimes slightly pinkish) and turning bright green afterwards. The "leaflet" (called pinnae in ferns) are pointed, sickle-shaped and their margin is somewhat undulate. In this species, the fertile fronds are quite different from the sterile fronds: dark brown in colour, their pinnae are very narrow. The clumps propagate slowly through short rhizomes, and very old plants sometimes form a small upright trunk. Under our climates, the plant will reach about 60cm (24in) in height and 1 to 1.50m (3 to 5ft) in width under good conditions, but in its original regions, each frond can exceed 2 metres (7 feet) in length!

Given its origins, Blechnum novae-zelandiae appreciates mild climates: its hardiness will not exceed -8° (17.6°F) to -12°C (10.4°F) in a sheltered position, and it should be reserved for regions where winter is not too harsh, but summers are not too hot or dry either, it is a plant typically adapted to the coast of the English Channel and Atlantic Ocean. Prefer light shade, which allows for a better expression of the color of the young fronds. This species requires an acidic, loose, humus-rich, moist to wet soil, but above all well-drained, otherwise the stump can rot. An addition of leaf compost can improve your soil if it is too heavy, but avoid planting it in soil that is too clayey and wet during winter. You can overcome this obstacle by planting on a cool slope or by raising the plant. It can also be grown in a pot, with careful watering.

If your climate allows it, go for a tropical garden by combining it with tree ferns (Dicksonia, Cyathea), even though other hardier ferns like Dryopteris sieboldii or Polystichum acrostichoides can also fill this role in a more moderate way. The Fatsia polycarpa, Boehmeria biloba, and Arthropodium cirratum will also make wonderful companions for an exotic and graphic atmosphere!