Athyrium otophorum var. okanum, commonly known as the Eared Lady Fern or Okanum Fern, is a unique variety within the Athyrium genus. It is valued for its distinctive fronds and vibrant colours.

Here's a detailed description and care guide for Athyrium otophorum var. okanum:

Description:
Athyrium otophorum var. okanum is a deciduous fern with an elegant growth habit. It features arching fronds that can reach a height of about 1 to 2 feet (30 to 60 cm) and spread to a similar width. The fronds are deeply divided and have a lacy appearance. The unique characteristic of this variety is the vibrant coloration. The fronds emerge with a bronze or coppery hue, gradually maturing to a rich, glossy green. The fronds also possess distinct "ears" or lobes at the base, which add to their visual appeal.

Care Guide:

Lighting: Athyrium otophorum var. okanum thrives in partial shade to full shade. It prefers filtered light or dappled shade. Avoid direct sunlight, especially during the hot afternoon hours, as it can scorch the delicate fronds.

Soil: This fern prefers moist, well-draining soil that is rich in organic matter. A loamy or sandy soil with good drainage is ideal. Adding organic compost or leaf mulch to the soil improves its fertility and moisture-retention capabilities.

Watering: The Okanum Fern appreciates consistent moisture to thrive. Keep the soil evenly moist, but not waterlogged. Water thoroughly whenever the top inch (2.5 cm) of soil feels dry. Adjust the frequency based on the climate and humidity levels of your region.

Humidity: Athyrium otophorum var. okanum appreciates moderate to high humidity levels. If the air in your home or growing area is dry, you can increase humidity by placing a tray of water near the fern or using a humidifier. Misting the fronds with water occasionally also helps to maintain humidity.

Fertilization: Eared Lady Ferns benefit from regular fertilization to promote healthy growth. Apply a balanced liquid fertilizer or a slow-release granular fertilizer formulated for ferns during the growing season. Follow the instructions on the packaging for the appropriate dosage and frequency.

Mulching: Apply a layer of organic mulch around the base of the fern to help retain moisture, suppress weed growth, and provide insulation to the roots. Avoid piling mulch against the crown, as it can cause rot.

Pruning: Regular pruning is not necessary for Athyrium otophorum var. okanum. However, you can remove any brown or yellowed fronds to maintain the plant's appearance. Prune damaged or dead fronds at their base. New fronds will emerge from the central crown.

Propagation: Eared Lady Ferns can be propagated through division. In early spring, carefully separate the clumps by gently pulling them apart. Ensure each divided section has healthy roots and foliage. Replant the divisions in suitable locations or containers.

Winter Care: Athyrium otophorum var. okanum is generally hardy and can withstand cold temperatures. However, providing some protection during harsh winters can be beneficial. Apply a layer of mulch around the base of the fern to insulate the roots. In extremely cold regions, you can also cover the plant with a layer of straw or horticultural fleece.

By following these care guidelines, you can enjoy the beauty of Athyrium otophorum var. okanum and its unique, colorful fronds in your garden or shaded areas. Adjust the care routine based on your specific growing conditions and monitor the plant for any signs of pests, diseases, or nutrient deficiencies.