Common Name: Sprenger's asparagus fern
Type: Herbaceous perennial
Native Range: Temperate southern Africa
Zone: 9 to 11
Height: 2.00 to 3.00 feet
Spread: 3.00 to 4.00 feet
Bloom Time: Seasonal bloomer
Bloom Description: White
Sun: Part shade
Suggested Use: Naturalize
Flower: Fragrant, Insignificant
Winter hardy to USDA Zones 9-11. Plants can be grown outdoors year round as long as temperatures never dip below 20-25 degrees 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 degrees 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 50F 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. Self-seeding can be mildly invasive in some subtropical to tropical areas (e.g., southern Florida and Hawaii).
Asparagus densiflorus, commonly called asparagus fern, is noted for its dense fern-like foliage which forms an arching mound that matures to 1-3’ tall spreading to 3-4’ wide. It is not a fern, however, but is a member of the asparagus family. It is native primarily to coastal areas in the southeastern part of the Cape of Good Hope in South Africa. It has escaped cultivation and naturalized in southern Florida where it has spread in a mildly invasive fashion. This ornamental asparagus is an evergreen 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 leaves (.75 to 1” long). Technically, the stems contain true leaves (tiny, inconspicuous and scale-like) and larger leaf-like phylloclades which have the form and function of leaves. Tiny, inconspicuous, pea-like, fragrant white flowers bloom in late spring to early summer. Flowers are followed by small red berries which ripen by fall. Plants have thorns, but the thorns are so small as to be often not noticed. This plant is also sometimes listed as Protasparagus densiflorus because plants in the genus Asparagus (e.g., the edible vegetable A. officinalis) have rhizomes but this plant does not. Species plants are not as widely grown in gardens as are certain popular cultivars such as ‘Myersii’ (foxtail fern) and Sprengeri group (emerald fern).
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.
No serious insect or disease problems. Watch for slugs, mites, mealybug and aphids. Leaf spot and rots may occur.
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.