Asplenium antiquum Osaka (Japanese bird's nest fern) is an excellent perennial indoor ornamental plant. It is an air purifying plant that produces a high level of oxygen. Asplenium Osaka is a rosette-forming fern up to 1 m wide. It has long glossy green leaves that have a wavy, ruffled edge, giving it a highly ornamental appearance.
 
Scientific name: Asplenium antiquum Osaka
Common names: japanese birds nest fern or birds nest fern.
 
How to grow and maintain Asplenium antiquum Osaka:
 
Light:
Prefers moderate and indirect light. Avoid direct sunlight and deep shade.
 
Ground:
It grows well in humus-rich soil. Use a peat-based potting mix. A peat-based mixture with organic material is also good. It prefers a soil pH of 5.5 to 6.5.
 
Water:
Water well during the growing season and always keep the soil evenly moist, but never allow your plant to become waterlogged. You can allow the topsoil to dry out slightly between each watering. During the winter months, reduce watering.
 
Humidity:
Humidity may need to be improved if it gets low and the plant is showing signs of being affected by dry air. You can increase the humidity by placing the plant in a humidity tray, or using an electric humidifier.
 
Temperature:
It thrives well and ambient temperatures between 18 and 24 degrees Cº are ideal, not lower than 13 degrees Cº.
 
Fertilizer:
During spring and summer, fertilize weekly or biweekly with a balanced liquid fertilizer diluted by half. Deformed leaves with brownish or yellow spots or edges are a sign of too much fertilizer.
 
Pests and Diseases:
They don't have serious pest or disease problems. But they are susceptible to attacks by scales, mites and mealybugs.