Scientific Name
Haworthia retusa var. nigra (M.B.Bayer) M.B.Bayer
Synonym(s)
Haworthia mutica var. nigra, Haworthia silviae var. nigra
Scientific Classification
Family: Asphodelaceae
Subfamily: Asphodeloideae
Tribe: Aloeae
Genus: Haworthia
Etymology
The varietal epithet "nigra (pronounced NY-gruh)" means "shining black" and refers to the original description of this variety made from a very dark clone from Kransriviermond.
Origin
Haworthia retusa var. nigra is native to South Africa. It occurs around Heidelberg in the Western Cape province.
Description
Haworthia retusa var. nigra, formerly known as Haworthia mutica var. nigra, is a small succulent that forms rosettes of fleshy, light green to very dark green leaves with a triangular, translucent end area marked with longitudinal lines. The rosettes are generally non-proliferous and can reach up to 3.2 inches (8 cm) in diameter.
The white flowers have greenish-brown veins and appear compacted on simple, slender stalks that can grow up to 12 inches (30 cm) long.
How to Grow and Care for Haworthia retusa var. nigra
Light: Place the potted plant in a bright area with some protection from the hottest rays of the day. White, yellow, or red-tinged leaves usually indicate that your H. retusa var. nigra receives too much sunlight. Deep shade tends to weaken the plant over a prolonged period. If your plant has spent the winter indoors, gradually move it outdoors into the bright sun to prevent sunburn.
Soil: Like all Haworthias, this plant does not like its roots to remain wet for prolonged periods, so the soil should be well-drained. Use a commercial potting mix for succulents, or make your own.
Temperature: This succulent likes warmer in the summer but cool temperatures in the winter. However, it does not like being too cold. H. retusa var. nigra can withstand temperatures as low as 30 °F (-1.1 °C). USDA Plant Hardiness Zones 10a to 11b, 30 to 50 °F (-1.1 to 10 °C).
Watering: In spring and fall, when the growth is most active, water H. retusa var. nigra thoroughly, then wait until the top of the soil dries out before watering again. Water your plant less during the winter when its growth slows down significantly. When this plant is mostly dormant during the hottest summer months, water it just enough to keep the leaves from shriveling.
Fertilizing: H. retusa var. nigra does not require much fertilizer. However, for optimum growth, fertilization is a good idea. Feed only with a dilute fertilizer and only during the active growing season.
Repotting: This slow-growing succulent can stay in the same pot for years. To keep your plant healthy and happy, repot H. retusa var. nigra into fresh soil every two to three years in spring or fall. Repotting time is also the time to take offsets for propagation.
Propagation: Since it is a plant with a solitary growth habit, H. retusa var. nigra can be propagated only from seeds or leaves. Sow the seeds in spring or fall in a well-draining soil mix.
Learn more at How to Grow and Care for Haworthia.
Toxicity of Haworthia retusa var. nigra
H. retusa var. nigra is considered non-toxic to humans and animals.
Links
- Back to genus Haworthia
- Succupedia: Browse succulents by Scientific Name, Common Name, Genus, Family, USDA Hardiness Zone, Origin, or cacti by Genus
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