Growing Non-GMO Black Bearded Iris Flower Rhizomes

Plant your iris rhizomes at least six weeks before the first hard frost. Choose a spot with full sun — at least six hours of direct sun daily is essential for reliable blooming — and well-draining soil. Amend heavy clay soils with coarse sand and compost to improve drainage. A slightly acidic pH of around 6.8 is ideal. Unlike true bulbs, bearded iris rhizomes should not be buried. Dig a shallow trench about 4 inches deep, form a mound of soil in the center, and set the rhizome on top of the mound with the roots spreading downward. The top of the rhizome should sit at or just above the soil surface. In very hot climates, light coverage of up to 1 inch is acceptable to prevent scorching, but burying them deeper than that will suppress blooming. Space rhizomes 12-24 inches apart to reduce the need for division in subsequent years.

Water the rhizomes in at planting to settle the soil and encourage root establishment. After that, water infrequently but deeply — most bearded irises require little supplemental watering beyond natural rainfall except during extended drought. Fertilize in early spring with a low-nitrogen fertilizer such as 5-10-10, and again after blooming. Avoid high-nitrogen fertilizers as these promote leafy growth at the expense of flowers. Remove spent flower stalks after blooming and cut foliage back to about 6 inches in late fall to reduce overwintering iris borer populations.

Growing Black Bearded Irises in Containers

For containers, use a roomy pot — a minimum of 12 inches wide and deep — with excellent drainage. Fill the pot to 1 inch below the rim and plant as described above, keeping the rhizome top exposed. Water only when the top 2 inches of soil feel dry. Container-grown irises benefit from being overwintered in a garage or shed in colder zones to protect the rhizomes from repeated hard freezes.

Black Bearded Iris in the Flower Garden

The near-black coloring of these bearded irises is genuinely rare and dramatic — in a season dominated by pastels and brights, a deep purple-black iris stops people in their tracks. The tall, stately blooms make them natural focal points in mixed perennial borders and striking companions for lighter-colored irises, white or yellow tulips, and early summer perennials. Mass plantings create a bold, sophisticated sweep of dark color that is unlike anything else blooming at the same time of year.

Harvesting Black Bearded Iris

Black bearded iris makes an elegant and dramatic cut flower. Harvest when the flower buds are just beginning to open and show color, using a clean, sharp knife or shears. Cut early in the morning, when the stems are fully hydrated, making a clean 45-degree angle. Place stems immediately in lukewarm water. Each stem carries multiple buds that open in succession, extending the vase life considerably.

About Black Bearded Iris Garden Rhizomes

Bearded irises belong to the species Iris germanica, also known as the German iris, and have been cultivated for thousands of years — appearing in ancient Egyptian palace art and inspiring the French fleur-de-lis. The genus name Iris comes from the Greek goddess of the rainbow, a fitting reference given the extraordinary color range of the species.

True black flowers do not exist in nature — what we call black irises are in fact an exceptionally deep purple or blue-violet that reads as black in most lighting conditions. The development of near-black bearded irises has been a long-standing pursuit among hybridizers, with celebrated varieties in this color class including Superstition, Before the Storm, and Black is Black. The rhizomes offered here are selected for their deep, dramatic coloring in this tradition.

Irises are not edible and are considered toxic to dogs, cats, and horses if ingested. Those with sensitive skin are advised to wear gloves when handling the rhizomes and foliage.

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Tips From Our Gardeners

The single most common mistake with bearded irises is planting the rhizomes too deep. If your irises produce plenty of foliage but few or no blooms, chances are the rhizomes are buried. Dig them up, reset them at the surface level, and the following spring you should see a much better bloom. Full sun and shallow planting are the two non-negotiable requirements for consistent flowering.

- Jerry Sawyer, True Leaf Market Writer

Black Bearded Iris Flower Rhizomes Per Package:

• 1 Rhizome Bag
• 3 Rhizome Bag

Non-GMO Black Bearded Iris Rhizomes are available for Fast Free Shipping on qualifying orders.