Acidantheras send up tall spikes of powerfully fragrant, creamy white flowers that open in sequence from the bottom to the top. Plants grow up to 3-1/2 feet tall, and the flowers are up to 4 inches across. The cream-colored flowers have red-brown markings, and bloom from August until October.
For best effect, group your plants in clusters in an area of the garden where their fragrance will be appreciated. They also make excellent cut flowers.
Once all danger of frost has passed, plant the corms in soil that has been enriched with compost or well-rotted manure. Choose a location in full sun that is sheltered from strong winds. Space the corms 6 to 9 inches apart and plant 4 inches deep. Give them a small dose of bulb fertilizer when they break ground and again in about a month.
Acidantheras need a long growing season, and in zones north of 6 it's a good idea to plant the corms indoors in pots about a month before last frost to give them a head start. Transfer the plants to the garden without breaking the soil balls, or plant pot and all in the garden. Cover plants if fall frosts arrive before flowering stops.
In zones 6 and colder, acidantheras must be dug up and stored in a frost-free area over winter. When the foliage dies back in the fall, dig up the corms, shake off the soil, and let them dry for a few days in an airy place out of the sun. Save the baby corms, too, but keep in mind that they will require two years to reach flowering size. Cut the tops back to 2 inches from the corms and pull off the dried remains of the previous season's corms. Store them over the winter in dry peat moss, perlite or vermiculite.
If the corms are left in the ground in Zones 7-10, lift and divide them every three or four years in early spring. Propagate from the small corms and cormels that develop at the base of the large corms. Plant the cormels in rich soil where they can build and grow. They should reach flowering size in two years.