Nierembergia plants are a genus of mat growing plants that reach from 5 to 60 cm in height.
They are usually grown as half hardy annuals in the garden, but are in fact half hardy perennials.
Nierembergia have small feathery leaves and white or purple flower that have an attractive purple inner; they come into bloom in the summer.
Their size and nature make Nierembergia an ideal plant to grow in rock gardens or as an edging plant.
Some common names for Nierembergia include Cupflower and Whitecup.
Common Names: Cupflower, Whitecup, Purplecup
Life Cycle: Half hardy perennial commonly grown as a half hardy annual by gardeners.
Height: 4 to 12 inches (10 to 30 cm).
Native: South America.
Growing Region: Zones 2 to 10. As a perennial in zones 7 to 10.
Flower Details: White, blue, purple, lavender. Often veined with deeper colours. Yellow or white centres. Cup-shaped. Upright.
Foliage: Oval. Feathery. Smooth.
Sow Outside: Cover seed. Before last frost or in autumn. Spacing 6 to 10 inches (15 to 25 cm).
Sow Inside: Germination time: two to three weeks. Temperature 70°F (21°C). Nine or ten weeks in advance. Transplant outdoors a few weeks before the last frost or in autumn.
Requirements: Full sunlight or light shade. Good drainage. Rich soil. Moist soil. Manure top dressing in spring. Regular watering to keep soil moist. Deadhead. Perennials should be cut back to the ground in autumn. Propagate: dividing in the spring; cuttings in autumn.
Cupflowers like to grow in a sunny part of the garden that has good drainage and a rich moist soil. The cupflower seeds can be sown either at the start of autumn or early in spring; once sown lightly cover the seeds with soil.
To grow cupflowers indoors, sow the seeds about 10 weeks in advance (Nierembergia Plants can be planted out in early spring or early autumn). They take about two to four weeks to germinate at 21 to 25 degrees centigrade. Once ready transplant into the garden about 15 to 20 cm apart.
Once growing it is important to keep the soil that Cupflower (and other Nierembergia) grow in moist. Nierembergia plants should be dead headed to produce more flowering, and cut back in the autumn. In the spring apply a top dressing of manure. If you require more Nierembergia then cuttings can be took in the autumn, or they can be divided in the springtime.