Iris germanica 'Gentius'

Description and Characteristics

Iris germanica ‘Gentius’ is a stunning cultivar of bearded iris, prized for its rich blue-purple blooms, elegant ruffled petals, and striking presence in late spring gardens. The large, showy flowers feature upright standards and slightly deeper-hued falls, with the classic fuzzy “beard” on each lower petal in a contrasting pale or lavender tone.

This rhizomatous perennial produces upright, sword-like grey-green foliage that remains attractive even when the plant is not in bloom. Typically growing to around 80–90 cm tall with a spread of 40–60 cm, ‘Gentius’ is ideal for adding vertical interest, architectural form, and vibrant colour to borders, cutting gardens, or formal beds.

It flowers in mid to late spring (May–June) and may produce a light rebloom in autumn in favourable climates. Like other Iris germanica cultivars, it is drought-tolerant, low maintenance, and highly valued for its longevity and pollinator appeal.

• Rich violet-blue ruffled flowers with pale beards

• Upright, clump-forming habit with architectural foliage

• Height: 80–90 cm; Spread: 40–60 cm

• Bloom time: May–June; possible light rebloom in autumn

• Ideal for sunny borders, cutting gardens, and formal designs

• Loved by bees and early pollinators

Growing Conditions and Maintenance

Iris germanica 'Gentius' thrives in full sun and free-draining soil, particularly when planted in a slightly elevated position to prevent waterlogging. Proper planting and division every few years help ensure long-term flowering success.

• Light Requirements:

  • Requires full sun (at least 6–8 hours/day)

  • Will tolerate partial shade but may flower less profusely

• Soil Preferences:

  • Prefers well-drained, neutral to slightly alkaline soil

  • Avoid heavy clay or waterlogged soils—raise beds if needed

  • Does not thrive in overly rich or wet conditions

• Watering Needs:

  • Water during prolonged dry periods, especially in the first season

  • Once established, drought-tolerant

  • Avoid overhead watering to reduce disease risk

• Feeding:

  • Apply a low-nitrogen fertiliser in early spring and just after flowering

  • Avoid overfeeding, which can reduce flowering and encourage rot

• Pruning and Division:

  • Deadhead spent flowers to encourage further blooms and prevent seed set

  • Cut back flower stems to the base after flowering

  • Divide clumps every 3–5 years in late summer (July–August) to rejuvenate and prevent overcrowding

  • When dividing, replant rhizomes just at or slightly above soil level

• Winter Care:

  • Hardy in Zones 4–9 (RHS H7); no special protection needed

  • Trim back any dead or damaged foliage in late autumn or early spring

Design Applications, Companion Plants, and Pollinator Value

‘Gentius’ brings bold colour, fragrance, and sculptural form to gardens. Its bloom period bridges the gap between spring bulbs and summer perennials, and its striking blue tone makes it a standout feature in mixed borders.

• Design Uses:

  • Ideal for cottage gardens, formal planting schemes, and herbaceous borders

  • Great for group planting or repetition along a path or terrace

  • Excellent in cut flower arrangements, where its bold colour adds drama

• Companion Plants:

  • Pair with peonies, alliums, salvia, nepeta, aquilegia, or early roses

  • Combine with silver foliage (e.g. Artemisia, Stachys) to highlight the rich blue tones

  • Add ornamental grasses or euphorbia for texture and contrast

• Pollinator Benefits:

  • Attracts bees, hoverflies, and other early-season pollinators

  • Provides nectar and pollen when other perennials have not yet bloomed

• Cut Flower Use:

  • Ideal for floral displays—cut when buds are just opening

  • Lasts 4–6 days in a vase with clean water and stem trimming

• Pest and Disease Tips:

  • May be susceptible to iris borer and rhizome rot in wet conditions—ensure airflow and drainage

  • Avoid covering rhizomes with mulch or soil

  • Generally deer and rabbit resistant

We currently only deliver within the island of Ireland, other countries can be quoted for by contacting [email protected] or via telephone on 06964084
 

Standard Delivery is FREE on orders over €250*

All standard deliveries will be completed within 5-7 working days via Fastway Couriers, any delay to this delivery time, the customer will be notified by One of our staff.

The in-Store delivery charge will vary compared with online, in-store delivery charge is done on a case by case basis. 

* Only mainland Ireland addresses qualify for free delivery.
 

Live Plants Delivery

Our live plants are packed with care and diligence by our staff, our horticulturists review each plant before despatch to ensure quality is maintained.
Live Plant delivery charges are not calculated on weight but on the space required per package to ensure safe delivery, so delivery charges may vary as some plants require more space than others when packed.
All live plants are despatched within 3-5 working days where possible, our couriers aim to deliver within 48 hours of despatch from our Garden Centre to allow the plant to arrive in healthy condition.
 

Click & Collect

Can’t wait for delivery? Why not try our FREE Click & Collect service? Simply make your purchase online and collect it from our store located in Croagh Co. Limerick. Our staff will contact you by phone when your order is ready for collection (Please allow 24 hours minimum). When collecting your item, call the store on 069-64084. We will then load into your car as required. This service is available in-store 9am – 6pm Monday – Saturday (No collections on Sundays)

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