Bastard iris – info, planting, care and tips

Bastard iris (Iris spuria)
Bastard iris (Iris spuria)

If you are looking for an easy-care iris species for full sunny locations, you will be enthusiastic about the purple flowering bastard iris. This is how to plant and care for the bastard iris properly.

Profile of bastard iris:

Scientific name: Iris spuria

Plant family: iris family (Iridaceae)

Other names: blue iris, spurious iris

Sowing time: spring

Planting time: spring to autumn

Flowering period: May to June

Location: sunny

Soil quality: sandy to loamy, calcipholous, humus rich

These information are for temperate climate!

Use in: flower beds, flower meadows ,group planting, overgrowing, borders, flower garden, natural garden

Winter hardiness: hardy, USDA Plant Hardiness Zones: 5 (-26 °C / -15 °F)

Bee and insect friendly: Yes

Plant characteristics and classification of bastard iris

Plant order, origin and occurrence of bastard iris

The bastard iris (Iris spuria) is originally native to southern and Western Europe, with isolated occurrences as far as Turkey and the Caucasus. In Italy and England, the perennial is naturalized, while in other countries it is considered a highly endangered and extremely rare species. Its occurrence is concentrated in river valleys and alternating humid areas. In botanical systematics it belongs to the iris family (Iridaceae). There are numerous subspecies of Iris spuria, which were crossbred with the related species Iris monnieri or Iris occidentalis. In trade, no distinction is often made between pure species and hybrid forms.

Characteristics of bastard iris


Iris spuria survives the winters with its branching rhizome and sprouts anew every spring. Through short runners it grows to a stately clump over the years. The flowers sit on 30 to 60 centimeter (12 to 24 in) high stems, the leaves can rise up to 100 centimeters (40 in).


Like all types of iris, bastard iris also forms belt-shaped, parallel-veined leaves. The narrow basal leaves protrude rigidly upright from the ground, the stem leaves sit in twos or more on the flower shoots.


In May and June, the bastard iris adorns with its flowers, which usually sit on the stems in twos or fours. The hanging petals are blue-violet, with a whitish-yellowish pattern at the base and red-violet veins. The upper petals have a darker violet tone. Specimens with flowers of different colors are cultivated forms of Iris spuria.


After fertilization, capsule fruits are formed.

Bastard iris – cultivation and care


Iris spuria definitely needs a full sunny and warm place.


A permeable, humusy loamy soil is best suited, which may be chalky. Most important is a good permeability, because Iris spuria tolerates a lot of soil moisture in spring, but wants to be as dry as possible afterwards.


Potted plants can be planted throughout the entire growing season, rhizomes are ideally planted between August and mid-October. Make sure to lay the rhizome flat in the soil and cover it with soil about 5 cm (2 in) high. It is advisable to fill a layer of sand into the planting hole beforehand to ensure good permeability. If the rhizome is to be used in a large area, calculate about 12 plants per square meter (10 sq ft).


Iris spuria takes two to three years to establish itself. Light composting in spring stimulates growth. During the budding phase in spring, watering is required as needed.


When the flowering tendency of bastard iris diminishes after a few years, it can be rejuvenated by dividing its rhizome. Ideally this should be done in late summer.


In order to cultivate pure offspring of the bastard iris, it is recommended to propagate by division of the rhizome. The native species can also be sown.

Diseases and pests

The greatest danger for Iris spuria is waterlogging, which can cause root rot.


Steppe iris is hardy. Some brushwood is recommended for very strong frosts in winter.

Use in the garden

Bastard iris is an enrichment for sunny open spaces with wild herbaceous character, but can also be used in sunny beds or on the dry edge of a watercourse. Pretty flowering partners are for example meadow sage, yarrow and meadowsweet.


Iris spuria is available in countless varieties:

‘Betty Cooper’ with light purple flowers, ‘Premier’ with strong purple flowers, the pure yellow ‘Archie Owen’ or the brown-red ‘Countess Zeppelin’, to name but a few.

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