Feriga de gradina - Dryopteris erythrosora 'Koidzumiana'

Dryopteris erythrosora 'Koidzumiana' , also known as the 'Japanese autumn fern' or 'red fern', is a cultivar of the species Dryopteris erythrosora in the family Dryopteridaceae. This perennial fern, evergreen in mild climates, is valued for its attractive foliage, with young fronds colored in shades of copper and pink, and for its adaptability to shady conditions. Native to East Asia, particularly Japan, 'Koidzumiana' is a more compact and colorful variant than the typical species, making it ideal for shady gardens, borders, rockeries or as an indoor plant.

Appearance of leaves, flowers and fruits

• Leaves : The fronds are bipinnate, lanceolate in shape, 30-50 cm long (shorter than the typical species). The young leaves appear in spring in bright shades of copper, pink or bronze , gradually maturing to a glossy green . On the underside, the spores (sori) are a distinct orange-red , hence the name "erythrosora" (red spores). The fronds have a glossy texture and an elegant arrangement, arching slightly.
• Flowers : Ferns do not produce flowers, reproduction being achieved through spores.
• Fruits : It does not produce fruit, but the sporangia (structures that contain spores) are visible on the back of the fronds, in reddish clusters, and are a subtle decorative element.

Growth characteristics

• Height and width : Grows to 30-45 cm tall and 30-60 cm wide , forming a compact, dense rosette with radiating fronds. It is smaller than other varieties of the species.
• Vigor : Slow to moderate growth, with new fronds appearing annually in spring. Forms a robust bush, which gradually spreads by short rhizomes.
• Type : Perennial fern, evergreen in mild climates (zones 7-9) or semi-evergreen in colder areas, where the fronds may partially die back in winter.

Growing conditions

• Exposure : Prefers partial shade to full shade , ideal under trees or in shady corners of the garden. Tolerates bright indirect light, but direct sun will burn the delicate leaves. Indoors, place near north or east facing windows.
• Soil : Requires fertile, well-drained soil rich in organic matter, with a slightly acidic to neutral pH (5.5-7). A mixture of compost, peat and garden soil is ideal. Tolerates moist, but not soggy, soils.
• Watering : Water regularly , keeping the soil consistently moist but not soggy. In containers, water when the top 2-3 cm of soil is dry, usually every 5-7 days. The fern appreciates moisture, but is more tolerant of drought than other fern species.
• Temperature : Hardy in zones 5-9 (down to -23°C), suitable for temperate climates, including Romania. In colder areas, mulch rhizomes in winter for protection. Indoors, maintain temperatures between 15-24°C .

Care and resistance

• Hardiness : Resistant to cold and most pests, including deer and rabbits, due to its robust leaves. May be affected by powdery mildew or leaf spot in humid, poorly ventilated conditions. Tolerates urban pollution.
• Fertilization : Apply a balanced liquid fertilizer (e.g. 10-10-10), diluted by half, once a month during the growing season (spring-summer). Avoid over-fertilizing, which can damage the leaves.
• Pruning : Remove dead or damaged fronds in spring to encourage new growth. It does not require extensive pruning as the natural shape is aesthetic.
• Pests and Diseases : Rarely affected, but may attract snails or slugs in wet gardens. Use organic traps or remove by hand. Inspect for mites in dry conditions.
• Propagation : Propagate by division of rhizomes in spring or by spores , although the latter is slow and less practical. Divisions must include healthy roots and fronds.

Dryopteris erythrosora 'Koidzumiana' is ideal for shade gardens , woodland landscapes , rockeries , borders or as an indoor plant in containers. Its colorful foliage in spring adds a warm contrast when combined with plants such as hosta, astilbe, heuchera or other green ferns. It is suitable for Japanese gardens, naturalistic spaces or near ponds, due to its moisture tolerance. Indoors, it is an excellent decorative plant for shady corners, with a subtle tropical effect. Its glossy leaves and red spores add textural interest all year round.

Origin

Dryopteris erythrosora is native to East Asia , including Japan, China, and Korea, where it grows in moist, shady forests or on rocky slopes. The fern cultivar 'Koidzumiana' was selected for its more compact stature and more colorful foliage, and is a rare variety, probably named after a Japanese botanist or horticulturist. It is less common than other forms of the species, but is highly prized by collectors for its unique appearance.

Pot diameter: 14 cm

Height with pot included: 30-40 cm

The actual plant size and color vary depending on the season.