Acidanthera
Acidanthera (Gladiolus callianthus) is an herbaceous perennial, mostly native to east Africa. It produces tall, feathery, purple flowers on dark stalks, often reaching up to 3 feet in height. Its foliage is medium green, and its clumps of leaves remain evergreen in warm climates. Acidanthera is often cultivated in gardens for its striking flowers, and while this plant is relatively easy to care for, its specific preferences must be met to maintain its health.
The Acidanthera requires regular watering and moist soil. The soil should be damp but not soggy, and should not dry out entirely. Plants can tolerate occasional water shortages, but regular watering will result in healthier growth. Watering should be increased in hot weather and decreased when temperatures cool. Watering should also increase when the plant is in bloom.
The Acidanthera likes partial sun for best bloom, particularly when grown near the equator. These plants should receive a few hours of direct sunlight a day, and will need filtered light if grown in a warmer climate. It thrives in shady conditions and will have smaller and fewer flowers in too much light. Access to full sun is only necessary if grown in cooler regions, where additional warmth strengthens its growth.
Acidanthera prefers warm weather and cannot tolerate cold climates. The ideal temperature range for this plant is 65 to 80 degrees Fahrenheit (18-27 Celsius). In areas with colder winters, the plant should be sheltered indoors or in a greenhouse with consistent temperatures. Cooler temperatures slow the growth and blooming of Acidanthera.
Acidanthera thrives in humid conditions, usually around 50 to 70 percent relative humidity. It should be misted regularly to increase humidity, particularly if kept in a room with air conditioning or in a dry environment. This will help preserve the leaves from desiccation and make the plant more likely to flower.
Acidanthera requires well-drained, moist soil with a pH level of 6.5-7.0. The soil should be a combination of peat moss, loam, and sand in equal parts. Compost can also be added to enrich the soil and provide additional nutrition. The potting container should have good drainage, with holes at the bottom for excess moisture to escape.
Acidanthera require fertilization during the active growing season. Inorganic or organic fertilizer can be applied to the soil every month or two. A slowly-released fertilizer or compost tea can also be added. Overfertilization should be avoided as it can cause salt damage to the plant. A balanced 20-20-20 fertilizer can help boost the growth and blooms.
The Acidanthera is not immune from pests, usually in the form of aphids and caterpillars. Aphids should be wiped off with a damp cloth or by spraying water, and caterpillars should be inspected for eggs and removed by hand. Insecticidal soap may be applied to heavily infested plants, but they should be used sparingly and in moderation. Chemical insecticides are not recommended.
This plant does not need to be repotted every year, but it should be moved into a larger pot every two or three years for optimal growth and health. The soil should be lightly moistened prior to repotting, and the planting container should be only a slight bit bigger than the existing pot. It's ideal to have a pot that is deep enough for the rhizomes and roots to expand in.
Acidanthera should be pruned regularly to promote its health. Pruning should mostly take place after the growing season, when the stems and stalks have withered away. Deadheading flowers and removing dead foliage can also help keep the plant healthy. Pruning can also be done to shape the plant into a desired size, shape, or height.
Mulching is recommended to keep the soil moist and cool. A layer of mulch such as compost, dried moss, or grass clippings can be applied to the top of the soil. A two-inch layer of mulch will add additional nutrients as it decomposes.
Acidanthera can be propagated through division or corms. Division is done by cutting the plant into several sections, typically with three or more corms and one established leaf each. Corms can also be planted directly in the soil in late summer. They should be planted an inch deep in a cool, moist spot and be watered moderately.
Acidanthera plants may need support during growth so they do not become top-heavy and bend with the weight of the blooms.Support can come from bamboo stakes and twine, as well as wire cages. The stems should be secured loosely 100 inches up the stems to prevent snapping.
Acidanthera require a rest period in winter to recharge and promote healthy growth. The plant should be given reduced amounts of water and sunlight during this period, and should be kept at cooler temperatures. In areas with cooler winter temperatures, the plant should be brought indoors or to a greenhouse for protection.
Acidanthera is generally not toxic to pets, although ingestion of large amounts may cause mild digestive upset. The plant should be kept away from small animals that are likely to chew or eat the foliage.