The plumosa fern, also called asparagus fern, is a perennial vine that is native to South Africa. The plant received its name due to its leaves being shaped like those found on a fern. Plumosa fern is a low-maintenance plant that grows well against walls and along fences. It is hardy in USDA growing zones 10 and 11, where there is low risk of freezing temperatures.
The plumosa fern has short cladode branches that have the appearance of fern leaves. The true leaf of the plant consists of dry scales on the cladode branches. Plumosa ferns produce white or pink fragrant flowers during the summer, and clusters of black or red berries form once the flowering period is complete.
Plumosa fern grows best when planted in a nutrient-rich soil that is well-draining, or a container filled with a mixture that is 2 parts loam and 1 part course sand. The plant responds well when grown in partial shade--with morning sun and afternoon shade. The soil should be tested prior to planting to verify it is acidic at a pH of 5.5 to 6.5. Ground rock sulfur can be worked into the soil two weeks prior to planting to lower the pH number.
The plumosa fern is considered drought-resistant but performs best when the soil remains evenly moist during the growing season. Supplemental water should be applied when the weekly rainfall is less than 1 inch. Do not overwater the plumosa fern or create standing water around the stem. Plumosa ferns should be fertilized each spring with a balanced 10-10-10 fertilizer. Old and dead branches should be pruned from the plant each spring to stimulate new growth. The shape of the plant can be controlled with light pruning after flowering is complete.
The seeds of the plumosa fern can be collected once they become ripe and planted immediately in a container filled with a moist seed-starting medium. Seeds that will be planted in spring should be dried and stored in a paper envelope. Plumosa seeds take 21 to 30 days to germinate when placed at a temperature of 60 to 70 degrees F. The plant can also be propagated by dividing the tuber roots in early spring. The entire plant should be dug from the ground and tubers divided by cutting with a sharp knife. Each tuber should have five to six eyes and a stem of green foliage.
Plumosa ferns should be monitored for the presence of aphids and spider mites. The plant can be sprayed with a sharp stream of water to remove the insects. Insecticidal soap sprayed on the underside of the leaves will prevent the insects from returning. Wet conditions at the stem of the plant can cause the fungal disease crown rot. The plant foliage will dry and break off and a white fungus will be present around the stem. Crown rot can be treated by removing and disposing of infected plants and treating the soil with a fungicide.