The leatherleaf fern is a shade-loving foliage plant native to South Africa. The fern prefers to grow at a temperature of 50 to 75 degrees F and will not tolerate freezing. For this reason, many people prefer to grow the fern indoors or in a greenhouse environment. The long foliage fronds are attractive and ideal for floral arrangements.
The leatherleaf fern is an upright growing evergreen plant that reaches a height of 1 to 3 feet with a spread up to 5 feet. The leaves have a triangular shape and are dark green and glossy in color with a coarse texture. Leatherleaf ferns produce an above-ground stolen where the green foliage grows from.
Leatherleaf ferns are hardy to plant outdoors in USDA growing zones 10 and 11 where there is no risk of freezing weather. Plants grown outdoors prefer a moist, acidic soil in a shaded location. The soil should be tested prior to planting to verify it has a pH of 5.5 to 6.5. Ground rock sulfur worked into the soil will lower the pH number. Leatherleaf ferns grown as a houseplant prefer a high-quality potting soil in a container with drainage holes. The plant performs best when placed in an area that receives indirect sunlight from a south, east or west direction.
Leatherleaf ferns growing outdoors require supplemental water when the weekly rainfall amounts are less than one inch. Collected rainwater is acceptable as long as it is not acidic. Indoor growing plants should be watered when the soil is dry to the touch to a depth of one inch. Use warm water to prevent shocking the plant. Fertilize indoor and outdoor growing leatherleaf ferns every two weeks during the spring and summer months. Apply a fertilizer that is water soluble and diluted to half strength. Place indoor ferns on a tray filled with stone and water to increase the humidity levels around the plant. Do not set the fern directly in the water as this will promote root rot.
Propagate leatherleaf ferns by dividing the plant in spring. Remove the plant from the container or ground and gently break apart the root sections so each division includes a healthy section of root and foliage. Plant the ferns at the same depth they were previously growing immediately after dividing to prevent the roots from drying.
Monitor leatherleaf ferns for the presence of mealybug, scale or mite insects on the plant. Remove the insects by spraying the plant with a sharp stream of water. Apply an insecticidal soap spray once the plant is dry to prevent the insects from returning. Leatherleaf ferns are susceptible to fungal diseases caused by over watering or planting in poorly draining soil.