All about Dietes Bicolor Plants

Dietes Bicolor is a rhizomatous perennial plant. It forms clumps at the base. If you leave these plants undisturbed for years, they can develop huge clumps. The species of this plant belong to the Iridaceae (Iris) family. The plant originates from rhizomes, under the soil. On average, a matured plant grows 1m tall and spreads 1m wide.

Dietes bicolor is also called fortnight lily or African iris. It has its native roots in South Africa. Gardeners in south Africa grow these plants in their gardens, backyard, spare areas, and even large indoor premises. Some decorators use this plant to beautify commercial premises as well.

In fact, some countries like south Africa have volunteers to conserve nature and also to decorate the public spaces, roadsides, etc. These groups use many ornamental plants including Dietes Bicolor for decorating the spaces.

Description of Dietes Bicolor Plants

Dietes Bicolor Leaves

Photo by David J. Stang (Wikimedia Commons) (CC BY-SA 4.0)

Typically, the long pale green leaves emerge from the clump base. Resembling ancient swords, these leaves grow about 2 – 3 feet tall. These narrow light green leaves sometimes have double central veins. Like other plants in the iris family, Dietes bicolor plants have symmetrically arranged leaves.

Dietes Bicolor Flowers

Photo by gailhampshire (Wikimedia Commons) (CC BY 2.0)

Generally, the flowers are yellow in color. There are some white variants also available in commercial markets. They have dark purple or dilute black spots. An orange outline or tint surrounds each spot.

These flowers originate from a capsule. Sometimes, these capsules grow heavy. In that case, the flower stalks bend down towards earth, as they cannot bear them in upright positions.

In the final stages, these capsules become dry and split open, dispersing brown seeds.

The flowers generally last for a day or two. Since the plant produces a large number of flowers, it appears as though the plant is full of flowers throughout the season. However, the flowering season is only spring and summer (Mostly, October to January), During this season, these plants attract onlookers with their beautiful flowers.


The Pollinating insects, usually bees, enter the flowers and push themselves inner, in search of nectar. While doing so, the pollen particles deposit on the insects’ bodies. The insects then fly to other flowers also to collect nectar. In this way, they transport the pollen particles from one flower to another. Hence, pollination occurs effectively.

As a result, many insectivorous birds roam around the garden areas to feed on these insects. The presence of these beautiful birds itself beautifies the garden’s manifolds.

Propagation of Dietes Bicolor Plants

Propagation of Dietes Bicolor Plants

Photo by El Funcionario (Wikimedia Commons) (CC BY-SA 4.0)

USDA recommends hardiness zones 8B through 11, to grow these plants. Dietes bicolor prefers to grow under sunlight. But it can also thrive in partial shades. The more sunlight it receives, the more the flowers it blooms.

These plants are well known for their drought-tolerant Characteristics. Hence, they are easy to maintain in almost any warm environment.


The division is one of the easiest methods to propagate Dietes bicolor plants. Start dividing the plants after the blooming season. Select large clumped plants for this process. Using sterilized equipment like sharp knives, shovels, etc., divide the rhizomes into several sections.

Dig a hole at least 3 -4 inches deep and a few inches extended than the width of the rhizomes. Then, pour some loose soil into the hole to form a ridge. Laying the root tubes down on either side, place the rhizome on the ridge.

Exposing the top portion of the rhizome, cover the hole with soil. Make sure to space rhizomes 1 -2 feet apart.

While planting, mix some low nitrogen fertilizer to feed the plants. Then, reapply another time in the spring. During the initial stages of growth water the seedlings regularly. This helps the young plants to grow and establish quickly.


Avoiding the coldest and hottest months, start sowing the seeds in the spring or fall. Typically, the optimum temperature for germination is about 15 – 20°C.

Normally, the seeds have a hard outer covering. Being impervious to water, this covering may delay or even stop germination. To overcome this problem, scarify the seeds before sowing. Then, follow the process as stated below

1.) Soak the seeds in water overnight

2.) Sow the seeds in pots containing seed starter mix. As the seeds need light for germination, barely cover them with soil.

3.) Using a good quality spraying bottle, mist the seeds with water.

Keep the pots in warm spots under shaded locations. Maintain the soil moisture by pouring water as needed. But avoid overwatering. Typically, the seeds may germinate in about 18 – 20 days (@ 15-20°C temperatures). Make sure to discard the dormant seeds.

After the seedlings sprout a couple of true leaf sets, you can transplant them in gardens.

Pests and Diseases

Most commonly, Nematodes and foliage Scales ruin the garden plants. Use a good quality chemical nematicide to treat Nematodes. Dip a cotton swab in rubbing alcohol and brush on the scale formation to remove it.

Normally, these plants can deal with any mild disease on their own. So, diseases may not be a major concern to the gardeners. You just have to enrich the soil with mild fertilizers and plant nutrients occasionally.

Maintenance of Dietes Bicolor Plants

Maintenance of Dietes Bicolor Plants.

Photo by peganum (Wikimedia Commons) (CC BY-SA 2.0)

Using good quality sterilized garden shears, cut off the decolorized leaves occasionally. By removing the seed pots, you can control the self-seeding of the plants. For more appealing looks, clip off the spent blooms. However, do not damage the healthy flower stalk until it deteriorates. It will continue to produce fresh blooms.

If you skip the pruning process for a long time, the plants may have many decolorized leaves and spent blooms. For an ornamental plant, this kind of look may be less appealing. In such cases, you can chop off the whole plant in the fall, leaving the base.

Then, feed the plant with well-balanced (NPK) fertilizer and water regularly. The plant will regrow readily, replenished with fresh energy by spring.

While gardening, we recommend you to use good quality garden Gears and sterilized garden tools. In addition to plant safety, this equipment ensures human safety also.

Uses of Dietes Bicolor



The lack of scientific studies on some herbs limits the indigenous herbal products development in many parts of the world. In spite of it, traditional medicines use herbs to cure many diseases.

However, science has confirmed the antimicrobial activity of the Dietes bicolor extracts. In fact, there is a great possibility of further scientific studies on the medicinal properties of these plants in near future.

Even before the confirmation from scientists, traditional medical practitioners have been curing many diseases using the extracts of these plants. Some of such diseases include toothache, cold, bruise, malaria, and flu.

Ornamental Usage

There are so many ornamental plants available in the market. Yet, some people specifically like the distinctive look and versatile characteristics of Dietes bicolor plants. Its long sword-like leaves and symmetrically arranged unique flowers attract many gardeners and decorative specialists alike.

You can use these ornamental plants to decorate almost any space including patio pots and decorative containers. It can thrive well in a wide range of temperatures beautifying your spaces. Generally, the architects use these plants to decorate water gardens, borders, unique commercial spaces Etc.,

Learn more about Dietes bicolor

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