About
Professor Blaauw' is a bulbous perennial to 60cm tall, with erect, narrow leaves and deep violet-blue flowers 8-10cm wide, the rounded falls with a yellow central mark, opening in mid spring and summer.
About the genus
Iris may be rhizomatous or bulbous perennials, with narrow leaves and erect stems bearing flowers with 3 large spreading or pendent fall petals, alternating with 3 erect, often smaller, standard petals, in late winter, spring or early summer
Growing conditions
SunlightFull sun
Soil typeClay, Loam, Sand
Soil pHAlkaline, Neutral
Soil moistureWell-drained
AspectSouth-facing, West-facing
ExposureSheltered
UK hardinessH5
Plant details
Plant typeBulbs, Herbaceous Perennial
HabitClump forming
FoliageDeciduous
Height0.5-1 metres
Spread0.1-0.5 metres
Time to full height2-5 years
Suggested usesCity and courtyard gardens, Coastal, Cottage and informal garden
ToxicityHarmful if eaten. Wear gloves and other protective equipment when handling. Pets: Harmful if eaten. For further information and contact numbers regarding pets, see the HTA guide to potentially harmful plants
Care notes
CultivationGrow in well-drained, neutral or slightly alkaline soil. See bulb iris cultivation for more information
PruningNo pruning required
PropagationPropagate by division, separating bulb offsets from midsummer to early autumn
Pest resistanceMay be susceptible to slugs, snails and thrips
Disease resistanceMay be susceptible to leaf spots, ink disease, rust diseases, bulb rot and viruses; see Iris diseases for more details