Geissorhiza radians, Winecups, Satin Flower, RARE! 10-50 seeds July 2024
Geissorhiza radians, commonly known as the winecup flower, is a critically endangered species belonging to the Iris family, with fewer than 10 viable sub-populations located in the southwestern Cape Town area of South Africa. These deep purple flowers feature large red centers and bloom in dense colonies, creating stunning displays from mid-September, especially near the town of Darling. Unfortunately, over 80% of their original seasonally wet lowland habitats have been permanently converted for agriculture or urban development. The remaining populations are further threatened by invasive alien plant species and fertilizer runoff. The dark-centered flowers are adapted to attract specific pollinators from the horsefly family (Tabanidae), although these interactions require further study. Each plant typically produces between one and six flowers and can also be found in smaller patches extending to Gordon's Bay. These plants predominantly inhabit seasonally moist wetlands, which dry out during the summer months.
Propagating Geissorhiza Radians from seeds
This species goes dormant in summer, so seeds are typically planted in autumn—September/October in the northern hemisphere and March/April in the southern hemisphere. Planting at other times is possible if temperatures are maintained between 45-75°F (7-23°C). If sown outside, seedlings might not enter dormancy during their first summer, which is acceptable. Store seeds in the refrigerator until autumn.
Use single or multiple pots that are 3-4 inches tall (7-10 cm). Space seeds about 1 inch (2.5 cm) apart and from the pot edges. In warmer climates, clay pots are preferred. Ensure pots have drainage holes.
Geissorhiza thrives in sandy soil. A suitable mix is 1 part potting soil to 2 parts coarse horticultural sand or medium-sized perlite.
Fill pots with the soil mix, placing seeds on top and covering with about 1/8 inch (3 mm) of soil. Water until evenly moist but do not saturate. Keep the soil surface moist without letting it dry out; if enclosing pots in plastic, allow for air circulation. Ideal germination temperatures are 60-77°F (15-25°C) during the day and 50-65°F (10-18°C) at night.
Seeds may sprout in 6 to 8 weeks but can take up to 3 months. After sprouting, provide sunlight, protecting from intense afternoon sun. Keep the top inch (2.5 cm) of soil moist.
Maintain even soil moisture during the growing season. When plants are 3-4 months old, add soil to deepen the bulbs.
This species prefers mild winter temperatures (40-80°F or 4-27°C) and protection from frost is essential.
Use a liquid fertilizer during the first year. Hydroponic fertilizer is effective for seedlings. Start with diluted (1/4 strength) fertilizer after one week and repeat every two weeks for the first three months. Avoid fertilization in spring.
When leaves start dying back in spring, stop watering and feeding. During summer dormancy, keep the soil relatively dry. It's best not to dig up the bulbs during their first year, as they will be small. Move pots to a cool, dry location until autumn. Lightly water in autumn and wait for leaves to appear. Bulbs may flower in their second or third season.