Bearded iris, plant and care guide

Bearded iris (Iris germanica), also called German iris, is a perennial flower that grows from a rhizome and blooms in the spring. Three upward petals and three downward petals form the bloom on stems 2 to 3 feet tall. The color of the blooms may be yellow, purple, blue, white or pink and may be bi-colors or mixed shades of one color. The center of the three downward-growing petals display a short and narrow strip of fuzzy-like growth. That fuzzy strip gives the iris its “bearded” name.

The plant has wide blade-like leaves. I planted groups of iris throughout the flower garden to add points of tall color. The leaves remain healthy and green into fall.

Iris rhizome

The rhizome of iris (what some call a bulb) looks like a lumpy root. Iris rhizome may be a series of rhizomes connected together reflecting age of plant in the ground. Digging up the rhizomes to break it apart offers the flower gardener the option to increase the size of the iris garden. See “Dividing the rhizome” below.

How to plant bearded iris rhizome

Plant iris in late summer or early fall (August or September). Choose a sunny location that drains well. Use a shovel to turn the soil to a depth of at least 8 inches. Rake the soil to break clumps and remove debris.

Plant the rhizome horizontally. Use your hand or a hand tool to create an opening in the soil deep enough to accommodate the roots of the rhizome. Allow the rhizome to lay close to the soil surface so about half of the rhizome is exposed. If planting multiple iris, set the rhizomes about 10 inches apart.

Digging up iris
Water the iris a day or two before digging. Dig in the morning while the ground is still a little moist. Use a shovel to remove iris from the ground. Another option that I use is a forked hand tool. I can scoop the rhizome from the ground using the fork portion of the tool.
 
Dividing the rhizome

Every three or four years, dig up the rhizomes in late summer and divide them to create more plants. Dividing the rhizome helps to prevent crowding that can result in fewer blooms. The mature rhizome appears somewhat like a series of long, thin potatoes joined end-to-end. Sometime, the rhizomes may expand outward like a Y. Cut the rhizome at groves in the rhizome, ensuring that each portion cut has at least two roots.

Pictured below is a large rhizome that can be broken into at least four  sections.

Care

Apply 1 to 2 inches of mulch such as pine bark chunks or leaf mold that will hold in moisture and help to block weed growth. After planting, water every seven to 10 days, if there is no rainfall and until the ground freezes. Continue to water every seven to 10 days the first year, spring to fall. After that, rainfall alone should be enough since iris are drought-tolerant.

Snip off the dead bloom to neaten the garden. Keep the leaves since the leaves provide nourishment for rhizome growth. The leaves can be cut back to about 6 inches in late fall. While the iris is blooming, apply a water-soluble all-purpose fertilizer if desired and according to the manufacturer’s instructions.

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