Asparagus densiflorus 'Sprengeri', or Sprenger's Asparagus Fern, a native of South Africa is not really a fern at all. Even though it may appear fern-like to the inexperienced eye, it has flowers and berries, so is clearly an angiosperm. It is highly modified. The needle-like leaves are actually short branches called cladodes. The true leaves are initially green, but remain on the plant as inconspicuous dry scales. The plant will reach from 2 feet (60 cm) to 6 feet (2 m) tall. Taller stems will weep and make the plant a good basket subject. It is hardy in USDA zones 9-11. When it escapes in the right climate, it is hardy enough to be very weedy and invasive. The berries and sap from the stems are considered poisonous.
Blooming Time: Summer: Flowers are pinkish white and very inconspicuous and are followed by clusters of red berries.
Culture: Asparagus densiflorus 'Sprengeri' need full sun to partial shade. The color of the plant seems to be best under 25% shade. The plant tends to yellow if grown in dense shade. A suitable soil mix consists of 2 parts peat moss to 2 parts loam to 1 part sand or perlite. Even though they have very fleshy roots and can withstand a fair amount of drought, they grow better if kept on the moist side during the growing season. During the winter months, it is best to grow them on the dry side, but being careful not to let them dry completely or they tend to have a lot of leaf drop. Fertilize in the spring with a balanced fertilizer and trim out old growth to make way for new lush growth. Repotting should be done in the spring before new growth begins.
Propagation: Asparagus densiflorus 'Sprengeri' are propagated by division and by seed. Seeds usually germinate in 21-30 days at 60-70° F (16-21°C).
Asparagus densiflorus 'Sprengeri' was featured as Plant of the Week July 15-22, 2004.
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