Alpine water fern

Blechnum penna-marina is a charming, diminutive evergreen fern that is native to the Southern Hemisphere but has proven to be very successful in UK woodland gardens. It is a low-growing plant that spreads slowly via rhizomes to form a dense, dark green mat of fronds, typically reaching no more than 10-15cm in height. The sterile fronds are leathery and lie flat, while the fertile fronds are held more upright and turn a striking bronze-red when they first emerge in spring. It is fully hardy (H5) and prefers a cool, moist, and acidic soil environment. It is an excellent choice for ground cover in a shaded rockery or as an under-planting for taller acid-loving shrubs like Rhododendrons. It keeps its appearance well through the winter, providing valuable texture. While it enjoys moisture, it should not be kept in waterlogged soil. It is a very tidy fern that requires almost no maintenance, and its spreading habit makes it effective at softening the edges of paths and stones.

Sun: Partial shade.

Soil: Moist, humus-rich, acidic soil.

Hardiness: H5 — down to −15°C.