The elegant fronds of the hard shield-fern are a decorative leaf ornament all year round in sunlit garden areas.
Profile of hard shield-fern:
Scientific name: Polystichum aculeatum
Plant family: wood fern family (Dryopteridaceae)
Other names: prickly shield fern
Planting time: spring
Location: no direct sun to partial shade
Soil quality: sandy to loamy, nutrient rich, humus rich
These information are for temperate climate!
Use in: individual position, group planting, planters, under wood planting, natural garden, rhododendron garden, potted garden, forest garden
Winter hardiness: hardy, USDA Plant Hardiness Zones: 5 (-29 °C / -15 °F)
Bee and insect friendly: No
Plant characteristics and classification of hard shield-fern
Plant order, origin and occurrence of hard shield-fern
The hard shield-fern like the male fern belongs to the family of the wood fern family (Dryopteridaceae) and generally to the true ferns (Polypodiales). In nature it rarely occurs in European ravine forests as well as shady, moist hillside forests up to heights of 2,000 meters (6,500 ft), sometimes it is also found in the Caucasus and parts of the Himalayas.
Characteristics of hard shield-fern
Polystichum aculeatum is a perennial fern with 60 to 100 centimeters (24 to 40 in) long fronds. These grow out of the rhizome in a more or less expanding funnel shape, either upright or arching overhanging. The beige, paper-like chaff scales on the leaf stalks are striking. Growing at the right location, the rhizome slowly spreads in the soil.
The hard shield-fern has long-stemmed, winter-green leaves that have a lancet-shape silhouette. The base is significantly narrowed. The dark green top of the leaves shines noticeable. Each frond is two to three times pinnate and feels quite coarse. The leaflets are oriented towards the tip of the leaf. They sit on the midrib, at most a short stalk can be seen. The lowest leaflet, which points to the tip of the leaf, is significantly larger than the rest. The edges on the leaf margin of the leaflets narrow into a short point.
The spores of Polystichum aculeatum sit in two rows on the underside of the leaf. The spore clusters are covered by round, shield-shaped membranes.
Hard shield-fern – cultivation and care
The hard shield-fern prefers an at least shady to partially shaded place. The higher the humidity and soil moisture, the more sunlight is tolerated.
For good growth of the hard shield-fern, the soil should be at least fresh and have a high humus content. Waterlogging is not tolerated by Polystichum aculeatum.
In the case of heavy or sandy soil, plenty of compost and leaf mold is mixed to the soil before planting. The evergreen Polystichum aculeatum is best placed in a sufficiently large planting hole in spring. Then you should water the fern well. Leave enough space so that its fronds come into their own. It should definitely be half a meter (20 in) in diameter.
Propagation by spores should be left to specialists. Propagation by pieces of rhizome is more practical for hobby gardeners. This works best in early spring. For this dig up the plant and divide with a sharp spade, then replant.
Care / Watering / Fertilization
Apart from a dose of compost in the spring, no fertilization is necessary. Since the fronds are evergreen, they are left on the plant in winter. Fall foliage from trees can be left in the bed and serves as a natural humus supply. Polystichum aculeatum is reluctant to transplant. If it is very dry, you should water the hard shield-fern.
The withered fronds can be cut back when the plants starts to sprout in spring. However, it is only a cosmetic measure. If you simply leave the old fronds, they will be covered over by the new green over time and enrich the soil with more humus as they decompose.
Diseases and pests
Like most ferns, the hard shield-fern is robust towards diseases and pests. Even slugs and nudibranchs do not touch the fronds.
The hard shield-fern is hardy down to 5 (-29 °C / -15 °F). There are no special winter measures necessary.
Use in the garden
The hard shield-fern comes into its own as a typical forest plant in a place on the edge of the wood, in a shade bed or in a fern garden. Beautiful garden sights result when the fronds overhang the edge of water or when the fern grows at the foot of a mighty tree trunk. In addition to other ferns and ornamental shrubs, stones or tree trunks can also be combined, and the hard shield-fern goes very well with rhododendrons. Polystichum aculeatum is also attractive in a large container on the terrace, where it gives shaded corners a natural, exotic flair. The fronds are also used in floristry.
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