Acidanthera is a summer-blooming bulb in the gladiolus family. The plants have upright, sword-like foliage and fragrant white flowers in late summer and early fall. Acidanthera is easy-to-grow in any sunny garden and it also grows well in containers. Known by many other names, including Gladiolus murielae, Gladiolus callianthus, Abyssinian gladiolus and peacock orchid.
START WITH A BETTER BULB
It’s easy to see the difference in quality when you compare two acidanthera corms side by side. Acidanthera bulbs are graded by size, measured in centimeters. Large corms grow into big plants that will give you a more beautiful display of foliage and flowers than smaller-sized bulbs.
Here’s how to get your acidanthera off to a great start.
SHADE AND SUN: Acidanthera should be grown in full sun. If you have a shady garden, consider planting the bulbs in pots. As the plants come into bloom, you can relocate the pots to the garden.
ZONE: Acidanthera corms are winter hardy in zones 7-11. In colder areas, either grow the bulbs as annuals or dig up the bulbs in fall and store them indoors for winter. Reference the USDA hardiness zone map HERE.
WHEN TO PLANT: These heat-loving bulbs do not tolerate freezing temperatures. If you will be planting the corms directly into your garden, don’t be too eager. Wait until the soil is warm -- around tomato-planting time. If you are growing the corms in containers, you can get started a couple weeks earlier.
WHERE TO PLANT ACIDANTHERA
FLOWERBEDS AND BORDERS: Acidanthera’s upright foliage makes an attractive addition to perennial borders. The late summer flowers are a welcome surprise, blooming when most other perennials have already come and gone. Enjoy their haunting fragrance in the garden, and be sure to grow extras as they are excellent cut flowers.
CONTAINERS: Acidanthera corms are slow to get started. To make sure they don't get overwhelmed by faster-growing plants, it's best to plant them in pots on their own. Plant about a dozen corms per 12” pot. To extend the bloom time, consider planting a handful of corms every 2 weeks, starting at the end of April and continuing into early June.
PLANTING IS AS EASY AS 1-2-3
1. In the garden, loosen the soil to a depth of at least 6”.
2. Plant large corms 5-6" deep; smaller ones 4" deep.
3. Cover with soil and water lightly.
PLANTING TIPS FOR ACIDANTHERA
Acidanthera needs warm, very well drained soil and lots of sun. If your soil stays cool through early summer and/or is on the heavy side, consider planting acidanthera in pots rather than in the garden.
You can expect the corms to grow very slowly for the first half of the growing season, so don't worry if you don't see any foliage until late June or early July.
This plant’s flowers are borne in clusters on slender stems. The stems rise from the base of the plant and blend in perfectly with the foliage, so you may not notice them until the flowers start to open.
Like many other bulbs, acidanthera looks best when the corms are planted in clusters of 6 or more. If the corms are planted 5-6" deep, the plants rarely need staking.
CARING FOR ACIDANTHERA AFTER IT HAS FINISHED BLOOMING
In areas where Acidanthera is not hardy, the corms can be treated as annuals and be discarded at the end of the season. You can also store the corms indoors during the winter and replant in spring. Wait until frost has damaged the foliage, cut it back and dig up the plants. Move the clumps to a sheltered location and allow them to dry completely. Store the dry corms in a dry place with good air circulation. The storage temperature during the winter months should be approximately 60-65°F.
If you grow acidanthera in containers, you can simply bring the containers indoors in the fall and store the corms right in the (dry) soil. In spring, dump out the soil and replant the corms.
In warm climates, acidanthera can form large, dense clumps (similar to crocosmia). Occasionally these may need to be divided.