Iris germanica: How to Plant Them?

When to plant irises?

Irises are best planted in summer and early autumn, between July and October, while the soil is still warm.

At this time, their rhizomes (the thick, root-like structures) are dormant, allowing the plant to establish well before winter.

Where to plant them?

Garden irises thrive in full sun, which ensures abundant flowering. They can grow in shade but won’t bloom! Ideally choose a sheltered spot, especially for taller varieties.

Plant them in dry, well-draining soil, as they dislike excess moisture, which can cause rhizomes to rot!

Avoid planting in compacted soil. If your soil is heavy, loosen it thoroughly beforehand and mix compost into the planting area.

Irises prefer neutral or slightly alkaline soils.

How to plant irises?

To successfully plant your irises:

• Start by preparing the soil thoroughly: weed if necessary, then loosen the soil with a garden fork, to a depth of 20 to 30 cm;
• If your soil tends to retain water, add compost;
• Dig a wide hole, then, in heavy, poorly draining soil, place a layer of gravel and form a small mound of soil for each iris. Planting distances should be between 25 and 50 cm, depending on the variety;
• Place the rhizome on this mound so that it is half-buried: the upper part should slightly protrude above ground level. In light, well-draining soil, mounding is unnecessary, but the top of the bulb should still be flush with the surface and visible;
• Backfill the hole, gently firm the soil, then carry out an initial watering to help the soil settle around the roots;
• Water moderately until established. Once established, avoid overwatering, as irises tolerate drought well, and excess moisture may cause rhizomes to rot.

Planting a German Iris (Iris germanica)

Caring for Bearded Irises

Once planted, irises require little maintenance. Remember to remove yellowing leaves to prevent the spread of diseases. Every 3-4 years, divide the rhizomes to revitalise your plants and encourage beautiful blooms.

Watch out for diseases: excessive moisture can cause rhizome rot. If this happens, it’s recommended to dig up the rhizome, cut away the rotten parts and let it dry before replanting.

Iris germanica, Bearded Iris or Garden Iris?

The irises grown in gardens are rarely “pure” Iris germanica. They are rather the result of numerous hybridisations, carried out by breeders, between species originating from Europe, the Middle East and North Africa. These hybridisations have led to the many varieties of bearded irises we know today, with their stunning colours and varied sizes.

It would therefore be more accurate to refer to them as garden irises or bearded irises to distinguish them from botanical species like the true Iris germanica, which grows wild in certain regions of Europe. The term “bearded” refers to the small tufts of hairs (the “beards”) found on the petals of these flowers, which are a characteristic feature of this category of irises.