Considered quite hardy, Iris brevicaulis (Zigzag Iris) is a low-growing perennial with zig-zag stems bearing long, lax and arching, glossy bright green leaves, 10-20 in. long (25-50 cm). In early to mid-spring, blue-purple to pale blue-violet flowers bloom among the leaves.
I. Appearance and Characteristics
Iris brevicaulis is a species in the genus Iris, it is also in the subgenus Limniris and in the series Hexagonae. It is a rhizomatous perennial, from North America.
Iris brevicaulis is the smallest in all the Hexagonae series of Louisiana irises. Its leaves and stalks are much shorter than the other species. It is similar in form to Iris virginica, The flowers are normally never seen above the foliage, due to the short zig-zagging flower stems and occasionally, due to the habit of the stems to lie along the floor, or it is often decumbent (meaning the branches growing horizontally but turned up at the ends).
It has a shallowly rooted, branching rhizome (about 10–25 mm in diameter), that can eventually form large colonies of plants (2 x 3 ft wide).
It has long, glossy leaves, which are ensiform (sword-like), and grow from the base (of the plant). They are bright green, and grow to between 40–70 cm (16–28 in) long and 15–40 mm (0.59–1.57 in) broad.
It has a zig-zagged stem (known in botany as fractiflex; hence the common name of Zig-zag iris) going at approx. 45 degrees angles (to each other), which grows to between 12–20 inches (30–51 centimetres) tall. It has about 3–6 flowers per stem, 1–2 flowers at each axil, and at the terminus of the stem.
It begins blooming in early to mid summer, from April to mid-July, or June (in the UK). Occasionally it does not produce flowers every year.
The flowers are produced in a range of blue shades, from violet-blue, to lavender, to purple-blue, to bright blue, to blue, and pale blue shades. There is occasionally a white flowered form. The large flowers are 3.5 to 5 inches (8.9 to 12.7 centimetres) across, with horizontal falls (sepals) that arch downward and upright standards (petals). The petals are dark-veined and smaller than the sepals, which have a yellow (or whitish-yellow) signal patch or stripe. It has a yellow pubescence (rudimentary beard) on the sepals, (sometimes called falls).
It has green styles and pale lavender style crests (which are ovate in form), and short anthers.
It has a 6-angled seed capsule (similar to Iris hexagona), which is 3–5 cm long. Inside the irregular, circular seeds have a cork-like coating which allows them to float and thus aid in dispersal in its wet habitat.
- Genetics
As most irises are diploid, having two sets of chromosomes. This can be used to identify hybrids and classification of groupings. It has a chromosome count of 2n=44. It has been counted many times, 2n=44-Simonet 1934, 2n=42 by Randolph 1958 and 2n=42, Randolph in 1966.
- Pollination
Iris brevicaulis is primarily pollinated by bumblebees. But it is also occasionally pollinated by hummingbirds. They are pollinated in different ways, the hummingbirds must use their head to push back the iris’ petals in order to gain access to the nectar. Pollen is then transferred on a hummingbird’s forehead.
- Toxicity
Like many other irises, most parts of the plant are poisonous (rhizome and leaves), if mistakenly ingested can cause stomach pains and vomiting. Also handling the plant may cause a skin irritation or an allergic reaction. The rhizomes (thickened roots) of Iris brevicaulis contain poison. If mistakenly eaten it could cause nausea, vomiting, abdominal pain, diarrhoea and an elevated temperature. The roots, seeds and plant sap can also cause skin irritation if touched.
Iris brevicaulis is the hardiest and most adaptable of all the Louisiana irises. Occurring a wide range of habitats. It is native to North America.
- Range
It is found in Ontario, Canada, up as far north as the north-east shore of Lake Erie. Also in many southeastern states of the United States, including Alabama (along various rivers,), Arkansas, Florida, Georgia, Illinois, Indiana, Kansas (Leavenworth,), Kentucky, Louisiana, Mississippi (around the Mississippi River basin,), Missouri, Ohio, Oklahoma, Tennessee and Texas. (including the Big Thicket forest).
- Habitat
Most Louisiana irises are found in the bayous of southern Louisiana, but Iris brevicaulis can tolerate drier soils than the other species and can also be found away from the swamp areas. It will grow in moist fields, damp prairies, wet meadows, moist woodlands, streams, riverbanks, marsh areas, around lakes, around ponds, in ravines at the base of wooded slopes (in Missouri) and in ‘Bottomlands’ (areas of low-lying alluvial land near a river). In places where moisture is generally high during the growing seasons (of fall (autumn), winter and spring).
II. How to Grow and Care
Zigzag iris thrives in well-draining soil and requires moderate watering to mimic its natural boggy habitat while avoiding waterlogged conditions. It is tolerant to partial shade but blooms best in full sun. A notable special care point for zigzag iris is its preference for slightly acidic soil, which can significantly affect its growth and flowering potential.
Sunlight
Zigzag iris likes sufficient sunlight. It needs to receive more than 6 hours of light per day and can be planted in a garden with no shade. It can also grow in slightly shady environments, but the quality of its blooms and disease resistance may decrease. Some varieties tolerate environments with less light and can grow in the shade of other plants.
Temperature
Plants of the Iris genus are mainly distributed in the temperate zones of the Northern Hemisphere. The majority of its species are hardy, except some dwarf species that require hay or bark to cover their roots to overwinter in cold regions. The need for water among different Iris species varies, too. Some Iris likes moist environments, and some species can even grow in water.
Watering
Thriving in its native swampy environments, zigzag iris has adapted to be tolerant of both moist conditions and brief dry spells. This species typically maintains a balance in water needs, leaning slightly towards preferring consistent moisture. For optimal growth, zigzag iris should be watered every week. As an herbaceous perennial commonly grown outdoors, zigzag iris’s ability to withstand temporary flooding is noteworthy, making it well-suited for rain gardens or areas with fluctuating water levels.
Soil
Zigzag iris likes loose, fertile, and well-drained soil, but can also grow in dry and barren earth. It likes slightly acidic or neutral soil with a pH value of 6.0-7.0. Sulfur can be added to improve alkaline soil, while lime can be added if the soil is acidic.
Fertilizing
Fertilize zigzag iris with balanced nutrition fertilizers in early spring as new growth appears, promoting robust foliage and vibrant flowers. Opt for a half-strength dilution; monthly applications suffice. Over-fertilization risks damaging zigzag iris, so adhere strictly to recommended quantities. During active growth in spring and summer, consistent fertilizing supports health and bloom quality. In fall and winter, reduce frequency as zigzag iris enters dormancy. Practical tip: Apply when soil is moist, not dry, to prevent root burn and ensure nutrient uptake.
Planting Instructions
It’s best to plant zigzag iris in the summer. Choose a spot with ample sunlight and good drainage, and turn up the soil to 25 cm deep. Then topdress with fertilizer and mix in evenly. When planting, you can cut the leaves to 15 cm in length, which helps reduce water evaporation and increase the survival rates. Finally, cover the rhizome in the soil. Avoid letting the roots get dehydrated for too long during planting, and water right after planting.
Pruning
Cut off the bloom-bearing stalks after blooming to reduce nutrition consumption. Some varieties may bloom again. In the fall, prune old and dry leaves to improve the plant’s inner ventilation and prevent pests and diseases.
Propagation
Native to North America, zigzag iris is adept at clonal spread, thriving in moist conditions along stream banks and low-lying areas. Propagation is typically achieved through division, ensuring sections have roots and at least one fan of leaves for successful growth. Cuttings, while less common, can also be rooted after a period of moist, warm conditions to promote root development. Careful handling and site selection that mimics zigzag iris’s natural habitat will enhance establishment and growth.
Transplanting
The prime time for relocating zigzag iris is during the vernal rejuvenation period, ensuring root establishment before summer’s heat. Opt for a sun-dappled spot with moist, well-drained soil. A friendly tip: ensure zigzag iris’s rhizomes are planted shallowly for best growth.
III. Uses and Benefits
Zigzag iris is a welcomed addition to beds and borders, cottage gardens, rock gardens, bog gardens, rain gardens, or along ponds and streams.
IV. Harvesting and Storage
Zigzag iris flowers can be harvested for bouquets. Choose not-fully-bloomed flowers and cut them off from the stem base obliquely with a pair of sharp gardening scissors. Quickly put the flower in a vase with clean water to avoid its dehydration.
