Beauty and the beard: Exploring the stunning bearded iris

The bearded iris or Iris germanica, also known as the German iris, is a popular and stunning perennial plant that is commonly found in gardens throughout the world. Known for their beautiful and vibrant flowers, cultivars of this iris species are well-known among gardeners and landscape designers alike. In this blog post, I’m taking a closer look at the bearded iris and explore its unique characteristics, growing requirements, and tips for care and maintenance.

Characteristics

The bearded iris is a herbaceous perennial plant that typically grows to a height of 28-35 inches (70-90 cm). Its long, thin, and pointed leaves are sword-shaped and grow in a fan-like arrangement up to 24 inches (60 cm) in length. The flowers of the many cultivars are large and showy, coming in a wide range of colors, including purple, blue, yellow, orange, white, and pink.

On a bearded iris, the self, falls, and guards are different parts of the flower that make up its overall appearance. Here is a brief explanation of each, as catalogs often refer to them:

Self: The self is the uppermost petal on the iris flower. It is often a solid color and can be a different color than the rest of the flower.
Standards: The standards are the upright petals that surround the center of the flower. They are broad, round, and slightly ruffled at the edges.
Falls: The falls are the three downward-facing sepals of the iris flower. They are typically a different color than the self and may have a pattern or markings on them.
Guards: The guards are the two outermost falls on the iris flower. They are typically larger and more upright than the other fall and may have a slightly different shape.
Beard: The flowers also have a distinctive “beard” of fine hairs on the falls, which gives this iris species its common name.

Botanical illustration of Iris germanica flower

The term tepal is often used to describe the undifferentiated petals and sepals of iris flowers. However, it is important to note that there may be some variation in the terminology used to describe the different parts of iris flowers depending on the source.

Growing Requirements

Iris germanica thrives in full sun to partial shade and prefers well-drained soil that is slightly acidic to neutral. This iris species is adaptable to a wide range of soil types, including sandy, loamy, and clay soils, as long as they are well-draining. Ensure that the soil is moist but not waterlogged, as bearded irises are susceptible to rot in overly wet conditions.

Tips for Care and Maintenance

To keep your bearded iris healthy and thriving, it is important to follow a few basic care and maintenance tips. Here are some key tips to keep in mind:

Water regularly: it requires regular watering, especially during the growing season. Water deeply and thoroughly, but avoid overwatering.
Fertilize in spring: Apply a balanced fertilizer in spring to help promote healthy growth and flowering.
Prune after flowering: Once the flowers have faded, prune the stalks back to the base of the plant to encourage new growth and prevent the plant from becoming too crowded.
Divide every few years: bearded irises can become crowded over time which can lead to reduced flowering and overall plant health. Thus it is important to divide the plants every few years to promote healthy growth and flowering.

Iris ‘Finalist’

Propagation

Dividing bearded iris is a simple and effective way to promote healthy growth and ensure that your plants continue to produce beautiful flowers year after year.

When to divide bearded iris

The best time to divide bearded iris is in late summer or early fall, after the plants have finished flowering for the season. In zone 5, it is typically in late August and early September. Dividing the plants during this time will give them plenty of time to establish new roots before the winter sets in.

Steps to divide bearded iris

Dig up the clump: Using a garden fork or shovel, carefully dig up the clump of bearded iris plants, being careful not to damage the rhizomes.
Separate the rhizomes: Once the clump is out of the ground, gently separate the individual rhizomes from the clump. Be sure to remove any dead or damaged rhizomes, as well as any foliage that appears yellow or wilted.
Trim the leaves: Using a clean, sharp pair of scissors or pruning shears, trim the leaves of the bearded iris plant to a length of 6-8 inches (15-20 cm). This will help reduce stress on the plant and prevent water loss.
Replant the rhizomes: Choose a sunny, well-drained location for the bearded iris plants and replant the rhizomes at a depth of 1-2 inches (2.5-5 cm). The rhizomes should be half or a quarter high on the ground. Be sure to space the plants 12-18 inches (30-45 cm) apart to allow for proper air circulation.
Water thoroughly: After replanting, water the bearded iris plants thoroughly to help them establish new roots.

Tips for success

Here are a few tips to keep in mind to ensure successful division of your bearded iris plants:

Use sharp tools: Use sharp scissors or pruning shears to avoid damaging the rhizomes and foliage of the bearded iris plants.
Discard any soft or rotten parts. Be on the lookup for damages by iris borers.
Allow the rhizomes to dry: After separating the rhizomes, allow them to dry in a cool, dry place for a few hours to help prevent rot.
Plant in well-drained soil: Bearded iris plants prefer well-drained soil that is slightly acidic to neutral. If your soil is heavy or poorly-draining, consider amending it with compost or sand to improve drainage.

Iris borers

Iris borers can cause significant damage to bearded iris plants, both by feeding on the foliage and by tunneling into the rhizomes. Here are some of the ways that iris borers can harm bearded iris plants:

Feeding damage: Iris borers are caterpillars that feed on the leaves and stems of bearded iris plants. They can cause significant damage to the foliage, which may become yellow or brown and start to wilt. Severe infestations can cause the leaves to die back completely.
Rhizome damage: Iris borers can also tunnel into the rhizomes of bearded iris plants, causing significant damage to the plant’s root system. This can weaken the plant and make it more susceptible to other diseases and pests.
Spread of disease: Iris borers can also spread diseases, such as bacterial soft rot, which can further damage the plant.
Reduced flowering: Severe infestations of iris borers can reduce the number of flowers that a bearded iris plant produces, or even prevent it from flowering at all.

To prevent damage from iris borers, it’s important to take steps to control their population. This may include removing infected plant debris, using insecticides, and practicing good garden hygiene. When introducing new iris plants into your garden, examine carefully the rhizomes for sign of borers.

Cultivars

There are more than 70,000 registered cultivars. The American Iris Society (AIS) is the official world registry of non-bulbous iris. Each iris variety is first registered with the AIS and can then later be introduced with its name on the market. In nurseries, irises are sold potted for $10-25. Specialized growers may sell them in fans in early spring or early fall. Newer varieties can be found in hybridizers’ catalogs for hundred dollars and more!

In my former garden, bearded irises were not my favorite except for the charming ‘Lindbergh’, a tall and prolific heirloom bearing smaller flowers, that came from my mother-in-law. But since creating my new peony garden, I have fallen in love with them again, introducing a few every year. As a result, my collection of about a dozen cultivars is now growing.

Here are some of the lovelies I have in my garden, a few acquired quite recently. They are mid-season bloomers, typically flowering in late spring or early summer. Stay tuned as I add more photos this upcoming summer.

‘Ancient Echoes’: striking and unique blooms. The flowers of ‘Ancient Echoes’ feature golden yellow standards (the upright petals) with a tawny rose border and deep red-black falls (the downward-facing petals) with a matching tawny rose border. The beard on the falls is a gold fuzzy color, which contrasts nicely with the dark falls.

‘Ask Alma’: a smaller iris (called intermediate) light apricot flowers with tangerine-tipped, white beards.

‘Batik’: distinctive and striking patterned blooms. The flowers of ‘Batik’ feature a base color of creamy white or light yellow, overlaid with rich, deep purple-blue veins and splashes of purple-blue pigment on the falls (the downward-facing petals). The standards (the upright petals) are a lighter blue-purple, often with a white margin.

‘Black Sergeant’: striking, almost-black blooms. The flowers of ‘Black Sergeant’ feature a base color of dark purple-black, which is accentuated by a prominent black beard on the falls (the downward-facing petals). The standards (the upright petals) are slightly lighter than the falls and may have a slight reddish-purple tint.

‘Cajun Rythm’: vibrant and showy blooms. The flowers of ‘Cajun Rhythm’ feature a base color of bright golden yellow, which is accented by fiery orange-red streaks and blotches on the standards (the upright petals) and falls (the downward-facing petals). The beard on the falls is a bright yellow-orange color.

‘Finalist’: elegant and understated blooms. The flowers of ‘Finalist’ feature a base color of creamy white or pale yellow, which is accented by subtle hints of lavender or light blue on the standards (the upright petals) and falls (the downward-facing petals). The beard on the falls is a soft yellow or white color.

‘Pink Attraction’: beautiful and striking pink blooms. The flowers of ‘Pink Attraction’ have light pink standards, while the falls are a deeper shade of pink with a yellow stripe in the middle.

‘Pumpkin Cheesecake’: large and showy orangey blooms. The flowers of ‘Pumpkin Cheesecake’ feature creamy yellow standards with a hint of peach, while the falls are a rich, deep pumpkin-orange color.

‘Queen Dorothy’: a vigorous and very reliable rebloomer. Its white flowers are edged mid-violet.