Culture
Winter hardy to USDA Zones 9-11. Plants can be grown outdoors year round as long as temperatures never dip below 20-25°F. Plants perform best in organically rich, consistently moist but well drained soils in part shade (bright indirect light or filtered sun). Avoid direct hot afternoon sun which may cause the leaves to yellow. Tolerates full shade, but foliage may turn a lighter green. Plants may die to the ground in light freezes, but roots remain hardy to about 20-25°F. North of Zone 9, plants can be grown in containers that are overwintered indoors. Asparagus fern is easily grown as a houseplant in the St. Louis area because it tolerates a wide range of temperatures, does not require high humidity and is easily pruned. It is best grown with a well-drained, peaty potting mixture. Water regularly from spring to autumn. It does not require winter dormancy, but appreciates a resting period with reduced watering over the winter months. Performs well with regular temperatures in summer and minimum 50°F temperatures in winter. This plant is often taken outside for the growing season and brought back inside in early fall. Pinch back stem tips as needed to maintain plant form and promote dense foliage growth. If plant loses its attractive shape, stems may be cut back close to the soil level to regenerate. Propagate by seed or division (separate tubers). Birds eat the berries and help spread the seed to new locations where the seed will often readily sprout. This plant is considered invasive in Australia and parts of the United States including Florida, Hawaii, and southern California. Check local regulations before adding this plant to your landscape.
Noteworthy Characteristics
Asparagus densiflorus, commonly called asparagus fern, is noted for its dense, fern-like, evergreen to semi-deciduous foliage which forms an arching mound that matures to 1-3’ tall and 3-4’ wide. It is not a fern, however, but a member of the asparagus family. It is native primarily to rocky, open woods, savanna thickets, and coastal areas of southeastern South Africa. This plant has been widely introduced to other parts of the world as an ornamental. It is considered invasive in Australia and parts of the United States including Florida, Hawaii, and southern California. This ornamental asparagus is a herbaceous perennial with outward-sprawling fibrous and tuberous roots from which rise numerous, semi-stiff, arching stems (to 24” long) covered with linear, needle-like green cladodes (.75 to 1” long). Cladodes are segments of stem that have the form and function of leaves. Tiny, inconspicuous, fragrant, white flowers bloom in late spring to early summer. The flowers are followed by small red berries which ripen by fall. The fronds have small thorns along their stems. Synonymous with Protasparagus densiflorus. Species plants are not as widely grown in gardens as are certain popular cultivars such as 'Myersii' and 'Sprengeri'.
Genus name is the classical name of this plant.
Specific epithet is in reference to the dense flowers along the stem and/or to the dense foliage.
'Sprengeri' features elongated, arching to cascading stems with an airy, feathery appearance. Mature plants will reach up to 2' tall and spread to fill a 4' area.
Problems
Watch for slugs, mites, mealybug and aphids. Leaf spot and root or crown rotting may occur. Leaf drop can be a nuisance when kept indoors, especially in winter. This plant is considered invasive in Australia and parts of the United States including Florida, Hawaii, and southern California. Check local laws and recommendations before adding this plant to your landscape.
Uses
Where winter hardy, it may be grown in borders or along foundations. Forms an interesting ground cover. Use in pots, containers and hanging baskets. Container plants make excellent houseplants for bright, sun-filtered areas. Green stems are valued by florists for adding to flower arrangements.