Blechnum spicant
Hard fern
Common names: Deer fern
At a glance
- Light
- Shade
- Pot size
- from 10 l
- Lifespan
- Perennial
- Hardiness
- Hardy down to −25 °C
- Water need
- High
- Origin
- Native to Germany
Photo: Hans Hillewaert · CC BY-SA 4.0 · Source
Description
The hard fern, botanically Blechnum spicant, is a native, evergreen fern with two kinds of fronds. The sterile fronds form a flat rosette: leathery, glossy dark green, 30 to 50 cm long, with narrow pinnae arranged like ribs on either side of the midrib. Later, fertile fronds grow from the centre. They stand upright, have much narrower pinnae, and turn dark brown after the spores ripen in late summer. In the wild, the hard fern grows in damp, acidic coniferous and oak woodlands, especially in rainy regions, and is the only representative of its genus in Central Europe. In the garden, it belongs in a cool, shady spot with acidic soil: under conifers, beside rhododendrons, on the north side of the house, or in a large container. It grows slowly but remains attractive throughout the year. It tolerates drought and heat poorly.
Care instructions
Plant the hard fern in a cool, shady spot without midday sun. The soil must be acidic, humus-rich and loose; on chalky soils, dig a large planting hole and fill it with acidic soil. Plant it in April or September so that the centre of the rosette stays free, and cover the ground with fallen leaves or needle litter. Water regularly, preferably with rainwater, because hard tap water contains lime. The soil should never dry out, but it should not stand waterlogged. No pruning is needed: cut off brown, dead fronds in March, before the new ones emerge from the centre. Typical mistakes are chalky soil, drought during hot weeks, and a site that is too sunny. In a container, use acidic soil and a pot with a drainage hole.
The care notes were machine-translated from German.
Soil & site
Soil pH
Soil type
humus-rich, moist, lime-avoiding, well-drained
The hard fern needs acidic, humus-rich soil that stays permanently fresh to moist, as in rainy coniferous and oak woodland. It strictly avoids lime: in limy garden soil it struggles and often dies. On such soils, dig a large planting hole and fill it with acidic leaf mould and conifer-needle soil, mixed with a little sand for drainage. It tolerates nutrient-rich, freshly fertilised soil poorly. Despite the moisture, waterlogging is out of the question; excess water must be able to drain away.
Feeding
Light feeder
The hard fern needs no fertiliser. In woodland soil it makes do with the humus that the fallen leaves supply, and too many nutrients tend to harm it. In autumn, leave leaves and conifer-needle litter lying under the plant; that is enough. You do not need compost either, as it is usually too rich in nutrients and not acidic enough. In a container, replace the top layer of soil with fresh, acidic soil every few years in spring.
Overwintering
The hard fern is fully hardy and stays green with its glossy, leathery fronds even in winter. In the bed you do not need to do anything. In frost without snow cover and winter sun the fronds can dry out; a loose cover of leaves or brushwood then helps. Water on frost-free days when the soil is dry. In a container, place the pot against a sheltered, shady house wall and wrap it in horticultural fleece or hessian so that the root ball does not freeze through.
Propagation
Methods
- Division
- From seed
The easiest way is to buy strong young plants from a perennial nursery, because the hard fern grows slowly and cannot be propagated quickly. Older plants form several rosettes over the years, which you can divide with a sharp spade in April. Put the pieces straight into acidic, moist soil and keep them evenly wet through the first summer. If you are patient, sow spores: they ripen from July to September on the upright fronds. As soon as these turn brown, cut them off and let the spores fall onto paper. Scatter them on moist, acidic seed compost, cover the container and place it somewhere bright but out of the sun. It takes more than a year until the first small rosette appears.
For your garden
Grow Hard fern yourself
Gartenkern tells you when frost is coming, when to sow and when to harvest, for your location.
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