Iris Bulbs & Varieties – A Practical Growing Guide

Iris are one of the most versatile flowering plants, offering a wide range of colours, forms, and growing requirements.

From dry garden beds to water gardens, different iris types suit very different conditions, making variety selection important.

Main Features

• Wide colour range from whites and yellows to deep purples and blues.
• Includes both bulb and rhizome types.
• Suitable for dry, moist, and even wet soils depending on species.
• Long-lived and low maintenance once established.

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Types of Iris

Iris fall into two main groups—bulb iris and rhizome iris—with many sub-groups suited to specific conditions.

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Key Iris Categories and Varieties

Bearded Iris (Iris germanica)

The most widely grown garden iris, recognised by the fuzzy “beard” on the falls.

• Best in well-drained soil and full sun.
• Excellent for drier garden beds.
• Varieties include ‘Blood Moon’ (burgundy and yellow) and ‘Braithwaite’ (deep purple/lilac).

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Siberian Iris (Iris sibirica)

Elegant, upright plants with fine foliage and smaller, delicate flowers.

• Tolerates moist soil better than bearded iris.
• Ideal for borders and near water features.
• Very hardy and low maintenance.

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Japanese Iris (Iris ensata)

Known for large, flat, velvety flowers.

• Prefers consistently moist to wet soil.
• Best in full sun with good water availability.
• Popular varieties include ‘Loyalty’.

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Dutch Iris (Iris hollandica)

A bulb iris widely grown for cut flowers.

• Easy to grow and low maintenance.
• Flowers in spring.
• Best in well-drained soil and sunny positions.

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Crested Iris (Evansia Group)

Shade-tolerant woodland iris.

• Includes Iris japonica and Iris cristata.
• Ideal for shaded gardens and under trees.
• Prefer humus-rich, well-drained soil.

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Louisiana Iris

• Water-loving, beardless iris.
• Thrive in wet soils and pond margins.
• Excellent for bog gardens and heavy soils.

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Reticulata Iris (Iris reticulata)

• Dwarf bulb iris.
• Very early flowering—from winter to early spring.
• Ideal for pots, rockeries, and borders.

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Californian Iris

• Adapted to Mediterranean climates.
• Prefer dry summers and well-drained soils.
• Suitable for low-water gardens.

Growing Conditions and Care

Position

• Full sun for most iris.
• Partial shade for woodland types like crested iris.

Soil

• Free-draining soil for most species.
• Moist to wet soil for Japanese and Louisiana iris.

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Soil Preparation

• Improve soil to 25–30 cm depth.
• Add compost for structure.
• Add grit or الرمل in heavy soils for drainage.
• Match soil type to iris variety.

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When to Plant Iris

• Bulb iris: Autumn.
• Rhizome iris: Late summer to early autumn.

Planting Guide

Bulb Iris

• Plant 8–10 cm deep.
• Space 10–15 cm apart.

Rhizome Iris

• Plant at soil level, slightly exposed.
• Space 30–50 cm apart.

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Watering and Feeding

• Moderate watering during growth.
• Avoid waterlogging for bearded iris.
• Moisture-loving species require consistent water.
• Apply light fertiliser if needed.

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How to Get the Best Out of This Plant

• Choose the right type for your soil moisture.
• Divide clumps every few years.
• Keep rhizomes exposed (bearded iris).
• Provide full sun for best flowering.
• Avoid overcrowding.

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Companion Plants

• Lavender and salvia for dry conditions.
• Daylilies and roses for mixed borders.
• Hostas and ferns for shaded or moist areas.
• Ornamental grasses for contrast.

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Planting Ideas and Landscaping Uses

• Cottage gardens.
• Water garden edges.
• Mass planting for seasonal colour.
• Mixed perennial borders.
• Rockeries (dwarf iris).

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Iris Bulbs are available from the following nurseries

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Climate Zones

• Australia: Most types grow well; match variety to moisture (bearded = dry, Japanese/Louisiana = wet).
• North America: Wide adaptability across USDA zones 3–10.
• UK: Reliable in most regions with attention to drainage.
• Europe: Excellent in temperate and Mediterranean climates.

More About Iris Species