Origin
Iris hexagona Walt. var. savannarum (Small) R.C. Foster, commonly known as Savanna Iris, is a native plant of the southeastern states of the United States, particularly found in Georgia, Florida, and Alabama.
Common Names
Savanna Iris is also known by various common names, including "Dixie iris," "hexagona iris," and "six-petal iris."
Appearance
Savanna Iris is a perennial herb that typically grows to a height of two to three feet and spreads up to two feet at the base. It has long and narrow leaves that are usually flattened and range from 18 to 24 inches in length. The plant has an attractive, vibrant purple-blue flower that blooms from May to June and measures two to three inches across. The flower is six-petaled, which is unique among irises. The plant produces an oblong capsule fruit that splits into three pieces, revealing shiny, large seeds in the fall.
Uses
Savanna Iris was traditionally used by Indigenous communities to treat various medical conditions such as infections and kidney ailments. Nowadays, the plant is mostly used for ornamental purposes in gardens and landscaping projects due to its attractive and unique flower appearance. It is also sometimes used for wetland restoration and water management projects because it can help control erosion. Moreover, the plant is an important source of nectar for bees, butterflies, and hummingbirds, contributing to the pollination cycle.
Light requirements
The plant Iris hexagona Walt. var. savannarum (Small) R.C. Foster prefers full sunlight exposure. The plant needs at least six hours of direct sunlight every day to grow. However, it grows well under partial sunlight as well.
Temperature requirements
The plant requires warm temperatures to grow properly. It grows well in USDA hardiness zones 7a to 10b, where the temperatures range from 0 °F to 40 °F (-17.8 °C to 4.4°C) in winter and between 30 °F to 95 °F (-1.1 °C to 35 °C) in summer.
Soil requirements
The plant prefers well-drained, moist but not waterlogged soil. It grows well in sandy or loamy soil that is slightly acidic or neutral, with a pH of 5.5-7.0. The plant needs fertile soil rich in organic matter to grow well. Adding compost or other organic matter to the soil before planting is recommended to improve soil quality.
Cultivation Methods for Iris hexagona Walt. var. savannarum (Small) R.C. Foster
Iris hexagona Walt. var. savannarum (Small) R.C. Foster is a native plant in parts of North America and therefore adapts well to its environment. Cultivation can be done either from seeds or rhizomes.
For seed propagation, sow in early spring or fall in a soilless mix. Keep moist and the seed tray in an area that receives ample sunlight. It can take up to 2-3 years for the plant to bloom.
Rhizomes can be divided in the fall into small pieces with good roots. Plant these rhizomes 3 to 4 inches deep in fertile, well-draining soil.
Watering Needs for Iris hexagona Walt. var. savannarum (Small) R.C. Foster
Irises require regular watering, especially during the growth period. During the first year of planting, water plants weekly to help develop good root systems. After that, you can supervise how often the soil gets dry and make sure to keep it moist.
It's essential to avoid the accumulation of water around the rhizomes, as this can lead to rot.
Fertilization for Iris hexagona Walt. var. savannarum (Small) R.C. Foster
Iris hexagona Walt. var. savannarum (Small) R.C. Foster doesn't require excessive fertilization. In the late fall, a top dressing of compost, manure, or any other organic fertilizer will help the plant to store nutrients for the following season.
The application of a balanced fertilizer in the early spring is an option. However, avoid overfeeding as this can lead to excessive leaf growth with fewer flowers.
Pruning for Iris hexagona Walt. var. savannarum (Small) R.C. Foster
After flowering, remove any spent blooms to encourage the growth of more flowers on side branches. However, avoid cutting back any leaves as these are critical for photosynthesis. You may trim back any yellow or damaged foliage, but do so with caution as injuries may lead to disease and rot of the rhizomes.
It's essential to avoid cutting back the entire plant in the fall. The dead leaves help to protect the rhizomes from the winter cold. Trim back the leaves to 4 inches from the ground in late winter or early spring.
Propagation of Iris Hexagona Walt. var. Savannarum (Small) R.C. Foster
Iris hexagona Walt. var. savannarum (Small) R.C. Foster can be propagated through various methods, including:
Division
Division is a common method used to propagate Iris hexagona Walt. var. savannarum (Small) R.C. Foster. The best time for division is during the dormant season, which is usually late summer or early fall. Carefully lift the plant out of the ground and gently shake off any loose soil. Divide the rhizomes into sections with a sharp knife, making sure each section has roots and leaves. Replant the sections immediately in a well-draining soil mix.
Seed
Iris hexagona Walt. var. savannarum (Small) R.C. Foster can also be propagated from seed. Collect the seeds in the fall when the seedpods have turned brown and are starting to split open. Sow the seeds in a well-draining soil mix and cover them lightly with soil. Keep the soil moist and maintain a temperature of around 70°F. Germination can take several weeks to a few months, so be patient.
Cuttings
Propagation through cuttings is another method, but it is rarely used for Iris hexagona Walt. var. savannarum (Small) R.C. Foster. Take stem cuttings in the spring or early summer and dip the cut end in a rooting hormone. Plant the cutting in a well-draining soil mix and keep it moist. Roots should develop within a few weeks.
Regardless of the propagation method, it is important to provide the new plants with proper care and attention until they are established.
Disease Management
Iris hexagona Walt. var. savannarum (Small) R.C. Foster is generally a disease-resistant plant. However, it is susceptible to some fungal diseases such as:
- Leaf Spot: This is caused by the fungus Cercospora species. The leaves will have circular, brown spots that eventually become dry and papery.
- Rust: Rust disease is caused by the fungus Puccinia iridis. Infected leaves develop small, yellow-orange pustules.
To manage these diseases, it is important to keep the plant clean and free from debris. Remove and dispose of any infected plant material. Fungicides can be used to manage the diseases, but prevention is the best approach. Practice good sanitation and avoid overhead watering.
Pest Management
Iris hexagona Walt. var. savannarum (Small) R.C. Foster is relatively pest-resistant. However, a few pests that can be problematic include:
- Thrips: These are tiny, slender insects that feed on the plant's leaves, buds, and flowers. Their feeding causes distorted growth and a silvery discoloration to the leaves.
- Slugs and Snails: These pests feed on the leaves and can cause significant damage. Look for slime trails in the morning to identify their presence.
To manage these pests, handpick any visible slugs and snails and dispose of them. Use a sticky trap to trap thrips. Chemical insecticides can also be used, but use them sparingly and according to the instructions on the label. A non-chemical approach is to use beneficial insects such as ladybugs.
