It is a cormous perennial growing to 70 to 100cm tall, with linear leaves and in late summer, numerous fragrant white flowers with a maroon (occasionally orange) blotch in the throat, on slender nodding stems. Widely cultivated, it is a common subject in western and southern European gardens, where the corms are lifted every year and stored in frost-free conditions.
I. Appearance and Characteristics
Gladiolus murielae is a species of flowering plant in the family Iridaceae, native to eastern Africa, from Ethiopia to Malawi. It has been given a number of English names, including Abyssinian gladiolus and fragrant gladiolus. It was formerly placed in the genus Acidanthera.
The species was first described as Acidanthera bicolor by Christian Hochstetter in 1844. In 1973, Wessel Marais included the genus Acidanthera in Gladiolus. As the name Gladiolus bicolor had already been published by John Gilbert Baker in 1877 for a different species of Gladiolus, Marais needed another name. He chose to call the species Gladiolus callianthus. Marais was apparently unaware that James Kelway had already published the name Gladiolus murielae in 1932, so that the name “G. callianthus” was superfluous. The epithet murielae honours Muriel Erskine; her husband had collected in Ethiopia the specimen on which Kelway based the name.
The species is often still offered for sale under the name Acidanthera bicolor, sometimes with murielae added as an infraspecific name, or even as the cultivar name ‘Murielae’.
It is a cormous perennial growing to 70–100 cm (28–39 in) tall, with linear leaves and in late summer, numerous fragrant white flowers with a maroon (occasionally orange) blotch in the throat, on slender nodding stems. Widely cultivated, it is a common subject in western and southern European gardens, where the corms are lifted every year and stored in frost-free conditions.
This plant has gained the Royal Horticultural Society’s Award of Garden Merit.
Hardiness: Zones 7–10 (6b with deep planting and mulching)
II. How to Grow and Care
Acidanthera is generally considered easy to care for, given its adaptability and minimal care requirements. A key special care point includes ensuring well-draining soil, as acidanthera is susceptible to root rot if waterlogged. Additionally, acidanthera thrives in full sun, necessitating a placement where it can receive ample sunlight. Limited to these primary care aspects, even gardeners with basic skills can cultivate acidanthera successfully.
Sunlight
The acidanthera prefers full sun, so it’s best to place your plant in a sunny area where it will receive adequate sunlight. Although it will still bloom in the shade, expect smaller flowers and droopy flower stalks. Moreover, a plant growing in the shade will produce flowers that are less vivid compared to one grown in full sun.
Temperature
While large-flowered hybrids are not winter hardy, some small species of acidanthera can tolerate winter temperatures to -9 ℃. Generally, the acidanthera is planted as a perennial and the corms are left in the ground. In colder climates, the corms must be dug up in the fall. Store them indoors and replant them in the next spring. The acidanthera can tolerate high temperatures well, as long as humidity and soil moisture is optimal.
Watering
Thriving in its native tropical habitats, acidanthera has adapted to regular moisture and exhibits a preference for consistent humidity. This species is moderately drought-tolerant but flourishes when watered every week. In cultivation, acidanthera should be maintained with a balance of moist soil without becoming waterlogged. Given its affinity for moisture, acidanthera is typically grown outdoors where it can benefit from natural rainfall patterns, especially during its active growing season which is influenced by the availability of water.
Soil
This fascinating ornamental plant performs best when planted in well-draining and fertile soil. If your garden is filled with clay and soggy soil, plant your acidanthera in raised beds to avoid waterlogging. You could also introduce additional organic material into the soil before planting. The ideal soil pH for this plant is between 6.0 and 6.5.
Fertilizing
For acidanthera, a balanced nutrition fertilizer is key, ideally a 10-10-10 NPK ratio. Fertilize biweekly during the growing season for robust growth and vibrant blooms. Reduce to monthly in late summer, and halt in winter. Use half the recommended dosage to prevent nutrient burn. Dilute liquid fertilizers to safeguard against root damage. Fertilization tailors to active growth and flowering, enhancing acidanthera’s vigor and bloom quality. Monitor soil moisture, as over-fertilization can coincide with drought stress.
Planting Instructions
You can plant the acidanthera in cut flower gardens, flower beds, patios, and containers using corms, but avoid doing so too early in the spring when the soil is still cold. Regardless of planting location, ensure good drainage – this is essential for the plant to thrive. If you are planting in a garden bed, plant the corms 13 to 15 cm deep. Plant spacing varies depending on the plant type, but typically ranges from 10 to 20 cm. Water the corms well after planting.
Pruning
Properly pruning the acidanthera helps keep the plant healthy. Dead or spent flowers are usually removed to ensure a continuous bloom time. Once all the buds have opened and faded, cut the stalk 5 to 8 cm above the ground. As for the leaves, only cut them when they dried out, but keep those that are still wilting.
Propagation
Acidanthera is effectively propagated through the division of corms. Carefully unearth the corms after the foliage has died back. Separate the offsets, which are smaller corms that form around the base. Ensure each piece has at least one healthy growing point for successful cultivation. Replant these promptly in well-draining soil, positioning them at an appropriate depth to promote robust growth.
Transplanting
The quiescent period of winter is the prime time for transplanting acidanthera, ensuring dormancy that leads to successful root establishment. Choose a sunny spot with well-drained soil. Gentle handling of corms secures a thriving return come spring.
III. Harvesting and Storage
Acidanthera rewards the gardener generously when they blossom. Harvest when the buds are colored and the first flower is open. Use sharp garden shears to harvest the spikes in the morning when the temperature is low, and put them in a vase with clean water promptly to avoid water loss. These beauties may have 7-14 days’ vase life.