Species

Iris x hollandicaDutch Iris

3 other cultivars

bulb corm tuber

Dutch Iris 'Professor Blaauw'

Iris x hollandica 'Professor Blaauw'

The Story

Plant Bio

Iris hollandica 'Professor Blaauw' is a bulbous perennial known for its vibrant blue flowers and upright growth habit.

This cultivar is particularly valued for its showy, large blooms and long-lasting cut flower performance.

Uses & Benefits:

Striking violet-blue flowers add elegance to garden borders and rock gardens.

Fragrant blooms enhance sensory appeal and attract pollinators.

Supports bees and butterflies, contributing to pollinator health.

SpeciesIris x hollandicaDutch Iris

Essentials

At a Glance

Plant Type

Bulb Corm Tuber

Height

24 inches

Width

6 inches

Light

Full Sun, Partial Sun

Zones

5, 6, 7, 8, 9

Water

Moderate

Humidity

Moderate

Lifespan

Perennial

Native To

Europe

Toxicity

All parts are toxic if ingested

Bloom period

Mid-spring – Late spring

In flower about 2 months of the year

Planting

How to Grow

Tuck rhizomes 2-3 inches deep in well-drained soil in early spring.
Water thoroughly after planting to establish roots.
Mist leaves regularly during the growing season for lush foliage.
Fertilize with a balanced fertilizer in early spring and after bloom.
Divide clumps every 3-4 years in late summer for optimal growth.
Mulch around plants to retain moisture and suppress weeds.

Pro Tip

Plant in full sun for best blooming and ensure excellent drainage to prevent rot.

Keep It Thriving

Care Guide

Do

Water consistently during dry spells 🌱
Apply fertilizer in early spring and after flowering
Divide clumps every 3-4 years to rejuvenate

Don't

Avoid overwatering to prevent rot ❌
Don’t plant in heavy, clay soils without amendment ❌
Refrain from disturbing rhizomes during blooming

Seasonal Care Calendar

Task	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Deadhead
Fertilize
Plant

Watch Out For

Pests & Diseases

Common Pests

Common Diseases

In the Garden

Landscape Uses & Companions

Landscape Uses

Elegant perennial border with tall, violet-blue flowersVanilla-scented hedge for sensory gardensArchitectural focal point in rock gardens

Companion Plants

Daylilies Peonies Salvia Allium Sedum

Multiply

Propagation Methods

Good to Know

Common Questions

Dutch Iris 'Professor Blaauw' questions

What zones can Dutch Iris 'Professor Blaauw' grow in?

Dutch Iris 'Professor Blaauw' is hardy in USDA Zones 5–9. Inside that range it survives winter in the ground; outside it, grow it as an annual or a container plant you protect.

Is Dutch Iris 'Professor Blaauw' deer resistant?

Yes — Dutch Iris 'Professor Blaauw' is rated deer-resistant. Deer typically pass it over, though extreme hunger can override any plant's defenses.

When does Dutch Iris 'Professor Blaauw' bloom?

Dutch Iris 'Professor Blaauw' typically blooms in mid-spring through late spring. Exact timing shifts a week or two with your zone — Sow's bloom calendar maps it to your garden.

Does Dutch Iris 'Professor Blaauw' need full sun?

Dutch Iris 'Professor Blaauw' does best in full sun to part shade. In hot climates, afternoon shade keeps blooms fresher longer.

Is Dutch Iris 'Professor Blaauw' drought tolerant?

Yes — once established (usually after the first full season), Dutch Iris 'Professor Blaauw' handles dry spells with minimal watering. Water deeply its first year to build the root system that makes that possible.