Iris germanica (Bearded Iris)

Bearded Iris Main Types

Bearded irises are classified by height and flower size into six groups. These classifications not only help gardeners understand what to expect from a particular iris variety in terms of size and bloom time, but they also assist in creating a garden design with continuous iris blooms throughout the season.

Since these groups bloom at slightly different times, combining specimens from different groups will extend your color display for a few weeks.

	Miniature Dwarf Bearded (MDB) Flower size: 2-3 in. (5-8 cm) Height: up to 8 in. (20 cm) Flowers per spike:1 or 2 Bloom: Earliest to bloom These are the smallest bearded irises, reaching up to 8 inches (20 cm) in height. Their blooms are also petite and often appear in early spring.
	Standard Dwarf Bearded (SDB) Flower size: 2-3 in. (5-8 cm) Height: 8-16 in. (20-40 cm) Flowers per spike: 3 or 4 Bloom: Begin blooms when Miniature Dwarf Irises are ending These are characterized by their smaller stature, typically growing up to 16 inches (40 cm) in height. They bloom in various colors and patterns, adding beauty and charm to gardens and landscapes.
	Intermediate Bearded (IB) Flower size: 4-5 in. (10-13 cm) Height: 16-28 in. (40-70 cm) Flowers per spike: 4 or 5 Bloom: Late Spring. Growing between 16 to 28 inches (40-70 cm) tall, these irises bridge the gap between the dwarf varieties and the tall ones. They bloom after the SDBs but before the TBs.
	Miniature Tall Bearded (MTB) Flower size: 4-5 in. (10-13 cm) Height: 16-28 in. (40-70 cm) Flowers per spike: 6 or more Bloom: Late Spring, Early Summer. Often called “Table Irises,” these plants reach heights of 16 to 28 inches (40-70 cm). They bear smaller flowers than the BBs and have delicate, slender stems. They usually bloom with the BBs and TBs.
	Border Bearded (BB) Flower size: 4-8 in. (10-20 cm) Height: 16-28 in. (40-70 cm) Flowers per spike: 7 or more Bloom: Late Spring – Early Summer. These irises are ideal for border plantings. Their bloom time usually overlaps with the TBs.
	Tall Bearded (TB) Flower size: 2-3 in. (6-8 cm) Height: 28-48 in. (70-120 cm) Flowers per spike: 7 or more Bloom: Late Spring, Early Summer. Last to bloom. The most commonly grown, TBs can reach a height of 28 inches (70 cm) and above. Their large, dramatic blooms appear in late spring or early summer. They are what most people picture when they think of bearded irises.

Why Should I Grow Bearded Irises?

Bearded iris can bring a wealth of benefits to your garden and make a great addition to your landscape for several reasons:

Variety of Colors and Sizes: Bearded irises come in almost every color of the rainbow and a range of sizes, from miniature to tall. This variety allows for endless design possibilities in your garden.

Long-Lasting Blooms: Although individual iris blooms last only a day or two, each stalk produces several buds that open in succession. With proper planning, your garden can have continuous iris blooms throughout the spring season.

Easy to Grow: Bearded irises are hardy and adaptable. They can thrive in a variety of soil types, though they prefer well-drained soil. Once established, they are also drought-tolerant.

Low Maintenance: Irises require minimal maintenance. Apart from dividing every few years to prevent overcrowding, they need little attention compared to other garden plants.

Deer and Rabbit Resistant: Bearded irises are generally resistant to deer and rabbits, making them a great choice for areas where these animals are common.

Attract Pollinators: Bearded irises attract a variety of pollinators, including bees and butterflies, helping to support local ecosystems.

Fragrant Flowers: Many varieties of bearded iris produce fragrant blooms, adding a sensory experience to your garden.

Architectural Foliage: The sword-like foliage of bearded iris provides an architectural element to the garden, offering visual interest even when the plants are not in bloom.

Cut Flowers: Bearded irises make great cut flowers. They can add a touch of elegance to any floral arrangement with their large, attractive blooms.

All these reasons make bearded iris a must-have in any garden.

Garden Design with Bearded Iris Flowers

The bearded iris is a versatile plant that can work well in many areas of the garden. When planning your garden design with bearded iris, consider these factors:

Plant in Masses: Bearded irises make a dramatic statement when planted in groups of three or more of the same variety. This allows the vibrant colors to make a real impact.

Border Plantings: The shorter bearded irises work well as border plants along walkways or garden beds, while the taller varieties make striking backdrops.

Mixed Beds: Bearded irises can be mixed with other perennials to extend the blooming period of your garden. Choose companions that bloom at the same time or after the iris to ensure continuous color. Good companions include roses, peonies, and late-blooming perennials such as salvia, daylilies, and Russian sage.

Rock Gardens: The dwarf varieties of bearded iris are suitable for rock gardens, where their bright colors can provide a contrast to the stone.

Cottage Gardens: Bearded irises are a staple in classic cottage gardens, where their old-world charm fits right in.

Cutting Garden: If you enjoy fresh flowers in your home, consider planting a section of your garden with bearded irises specifically for cutting.

Drought-Tolerant Landscapes: Once established, bearded irises are drought-tolerant and can be used in xeriscaping.

Companion Plants for Your Bearded Irises

Choosing companion plants for bearded irises can enhance your garden by providing a pleasing aesthetic mix and ensuring continuous color throughout the season. When selecting companion plants, consider those that have similar sunlight and soil requirements. Here are a few great options:

Salvia (Salvia spp.): These plants bloom around the same time as irises and can provide beautiful contrasting colors and shapes.

Daylilies (Hemerocallis spp.): The strappy foliage and vibrant flowers of daylilies contrast beautifully with the sword-like leaves and delicate blooms of bearded irises.

Roses (Rosa spp.): Roses and irises are classic companions. They both appreciate well-drained soil, and the roses will continue to add color to the garden after the irises have finished blooming.

Peonies (Paeonia spp.): Peonies bloom around the same time as bearded irises, and their lush, rounded form provides a nice contrast to the verticality of the iris.

Russian Sage (Perovskia atriplicifolia): The light, airy nature of Russian sage, along with its later blooming time, provides a great contrast to the iris and can help extend the bloom season in your garden.

Catmint (Nepeta spp.): Catmint is another plant that pairs well with irises, with its grey-green foliage and blue or white flowers that bloom in late spring and early summer.

Ornamental Grasses: The vertical lines and feathery plumes of ornamental grasses complement the architectural foliage and bold blooms of irises.

Coneflowers (Echinacea spp.): Coneflowers bloom in the summer, after the irises have finished, and their large, daisy-like flowers add a different shape to the garden.

Remember to also consider factors such as the mature size of the companion plants, so that they won’t crowd out or overshadow the irises.

Growing Tips

Bearded irises are relatively easy to grow if you provide the right conditions. Here’s how you can grow them in your garden:

Planting:

• Bearded irises prefer a sunny spot with well-draining soil. They should get at least 6 hours of sun a day. They tolerate light shade, but the best flowering and disease resistance occurs in full sun.
• They are usually planted from rhizomes, which look like long, thin potatoes.
• The best time to plant is in late summer to early fall. This gives the rhizomes time to establish before winter.
• Plant the rhizomes just beneath the soil surface. In warmer climates, the top of the rhizome can even be exposed. They should be spaced about 12-18 inches (30-45 cm) apart.
• Arrange the rhizomes so the fan of leaves is facing towards the sun.

Watering:

• Water thoroughly at planting time and regularly for a few weeks to help them get established.
• Once established, bearded irises are drought-tolerant, but they will benefit from watering during dry periods.

Fertilizing:

• Bearded irises benefit from fertilization in early spring and again after blooming. Use a low-nitrogen fertilizer, such as 6-10-10.

Maintenance:

• After the flowers have bloomed and died back, cut off the flower stalks to the base to prevent the plant from putting energy into seed production.
• Leave the foliage on the plants until it has yellowed in the fall as it continues to provide nourishment to the rhizome for the next year’s growth. Then trim it back to about 6 inches (15 cm).

Dividing:

• Every three to five years, bearded irises should be divided to maintain vigorous blooming. You’ll know it’s time to divide when the center of the plant looks crowded and has fewer flowers.
• To divide, lift the clump of irises with a garden fork. Cut apart the rhizomes with a clean knife, ensuring each division has at least one healthy fan of leaves and a portion of the rhizome. Discard any old or diseased portions.
• Replant the divisions as described above.

Following these guidelines should help you grow beautiful bearded irises in your garden.