Iris ‘Clarence’

Iris ‘Clarence’: A Fragrant, Award-Winning Reblooming Beauty

Iris ‘Clarence’ is a reblooming tall bearded iris that earns its place in any sunny garden with its striking two-tone blooms and delightful fragrance. With white standards lightly tinted violet and falls in soft blue-violet shades, this iris is a showstopper. It stands tall at up to 89 cm (35 inches) and blooms not just once but often twice a year. Bred by the renowned hybridizer Lloyd Zurbrigg in 1991, Iris ‘Clarence’ has won numerous awards, including the Wister Medal in 2000, a testament to its beauty and vigor.

A member of the Iridaceae family, this herbaceous perennial adds elegance and height to beds and borders while providing pollinator interest and deer resistance. Easy to care for and highly rewarding, this iris combines old-fashioned charm with modern performance.

The Allure of Iris ‘Clarence’

Iris ‘Clarence’ is a tall bearded reblooming iris, meaning it not only puts on a spectacular display in late spring to early summer but can bloom again in late summer or early fall under the right conditions. It forms upright clumps of sword-shaped foliage, offering vertical structure even when not in bloom.

Each flower features upright white standards delicately brushed with violet and broad, pendant falls in a cool blue-violet hue with striking white centers. The beard is creamy yellow, adding warmth and dimension. Petals are fragrant, with a sweet, soft perfume that lingers on warm days. Each plant produces multiple flowering stems, with up to 7 or more blossoms per stem and up to 5–6 buds per branch.

Awards and Recognition for Iris ‘Clarence’

This iris didn’t become a garden staple by chance. It earned:

• Honorable Mention (HM) in 1995
• Award of Merit (AM) in 1997
• Wister Medal in 2000

These accolades underscore the plant’s reliability, vigor, bloom performance, and overall garden value.

How to Grow Iris ‘Clarence’

Growing Iris ‘Clarence’ is straightforward for gardeners in USDA Hardiness Zones 3 through 10. It performs best with full sun and well-drained soil. Like all tall bearded irises, proper planting and maintenance are key to encouraging both spring and fall bloom cycles.

Light

Iris ‘Clarence’ thrives in full sun. Aim for a minimum of 6 hours of direct sunlight daily. While it can tolerate partial afternoon shade, especially in hotter climates, insufficient sun may reduce flowering.

Soil

Well-drained soil is critical. Sandy or loamy soils are ideal. If you have clay soil or live in an area with high rainfall, plant rhizomes in raised beds or on gentle slopes to prevent water from collecting around the base. This helps reduce the risk of rhizome rot.

Soil pH should be neutral to slightly acidic (pH 6.0–7.0). Avoid overly rich or organic-heavy soil, which can lead to rot.

Watering

Water consistently from early spring until about 6 weeks after flowering ends. Allow the soil to dry slightly between watering. Although once established Iris ‘Clarence’ is somewhat drought-tolerant, regular water is crucial to support reblooming. Reduce watering during dormancy or in periods of prolonged rain.

Fertilizing

Feed in early spring when new growth appears, and again in mid-summer after the first bloom cycle if you are encouraging reblooming. Use a balanced fertilizer (such as 10-10-10) or a low-nitrogen blend like 5-10-10 to promote blooming over foliage growth. Avoid overfertilizing, as too much nitrogen will encourage soft, rot-prone growth.

Planting

Plant rhizomes from late July through early October. Choose your planting time based on your region—earlier in cold-winter areas, later in mild-winter climates.

• Set each rhizome horizontally, with the top one-third above the soil surface.
• Space rhizomes 30–50 cm (12–20 inches) apart.
• Fan the roots out beneath the rhizome for support.

If you’re dealing with compacted soil, create a mound or ridge and rest the rhizome on top. Water thoroughly after planting.

Mulching and Winter Care

Avoid mulching directly over rhizomes. In colder climates, a light layer of mulch can protect against frost heave, but remove it in spring to prevent rot. In mild zones, winter protection is generally unnecessary.

Pruning

Cut back bloom stalks after flowering to prevent seed formation and redirect energy into the rhizome. In fall, trim foliage down to about 15 cm (6 inches). Remove any diseased or damaged leaves promptly.

Division

Every 3–4 years, divide the clumps in late summer (August) to prevent overcrowding, which can lead to fewer blooms. Lift the clump with a garden fork, cut away the older central rhizomes, and replant the healthy newer ones.

Propagation of Iris ‘Clarence’

Like most tall bearded irises, Iris ‘Clarence’ is propagated by division. This is best done in late summer after the bloom season is complete. Make clean cuts between healthy rhizomes, discarding any that are soft or discolored.

Pests and Diseases

Several pests and diseases can affect Iris ‘Clarence’, though proper care minimizes risk:

Common Problems:

• Iris borers: Tunnel through rhizomes causing rot. Remove infected foliage immediately and discard it far from your garden.
• Slugs and snails: Chew on leaves and petals.
• Aphids and thrips: Can cause leaf streaking and transmit viruses.
• Leaf spot: Fungal disease that discolors and kills foliage.
• Root and crown rot: Typically due to poor drainage or buried rhizomes.

Prevention Tips:

• Maintain good air circulation.
• Remove spent blooms and old foliage regularly.
• Avoid overhead watering.
• Sanitize tools and dispose of infected plant material in the trash, not compost.

Garden Design Ideas with Iris ‘Clarence’

Use Iris ‘Clarence’ in perennial borders, sunny foundations, or mixed cottage gardens. Its cool-toned blooms pair beautifully with plants like peonies, columbines, or salvia. Consider layering it with shorter plants that bloom later in summer to cover the gap between its first and potential second bloom.

Its stately height—about 75–90 cm (30–35 inches)—makes it ideal for the middle or back of a garden bed. The foliage offers structure and interest even when it’s not in bloom.

Reblooming Notes

While Iris ‘Clarence’ is a known rebloomer, it’s not guaranteed to flower again in fall every year. Factors that increase your chances of reblooming include:

• Full sun
• Well-timed fertilizer
• Summer watering
• Healthy, mature plants

Reblooming is often more successful in warmer zones (6–9), though reports of repeat flowering in colder climates do exist.

Summary

Iris ‘Clarence’ is an outstanding tall bearded iris for gardeners looking for color, fragrance, and the bonus of potential reblooming. With showy two-tone flowers, deer and drought resistance, and easy maintenance, this iris shines in sunny beds and borders. Award-winning and adored for good reason, it’s a perennial performer that brings grace to gardens from spring into fall.