When is the best time to transplant iris'?? I am wanting to put them in another part of the yard.

I always wait until they have finished blooming. If I am interested in getting a certain color or variety moved then I mark it with a labeled popcicle stick.

IRIS, TALL BEARDED

The iris plant is a great perennial for any garden. Irises come in a rainbow of flower colors and the foliage provides interest in the garden almost year round.

Actually, if you’ll pardon my this little grammar lesson, the root of the word iris is derived from the Latin or Greek word iris for rainbow—Iris from Greek Mythology is the goddess of the rainbow and messenger of the gods.

The leaves of the iris are swordlike in shape and range from green to gray green in color. There are several different types of iris that will provide diversity of flower shape and size in your garden. The most popular type of iris in our area is the bearded iris. In particular, the tall bearded iris will provide a great show, with foliage and flower stalks ranging from 30-50- inches tall and blooms up to 8 inches across.

The iris flower is composed of three main parts: three drooping petal-like sepals called falls; three usually erect petals called standards and three narrow, petal-like styles. Bearded iris is so named for the hairy tuft that appears on the falls. They are further classified by height as dwarf, intermediate and tall. And then subdivided flower size, type, color and season.

Bearded iris prefer full sun, and a deep, well-drained loamy soil. Bearded iris can be propagated by dividing the root systems. Clumps of roots should be dug when the irises have gone into their post flowering dormant stage. Divisions of irises consist of a rhizome –sometimes called the “foot” of the root system, a fan of leaves that should be cut back to about six inches for transplanting, and feeder roots. If you have been given a gift of iris divisions from a friend, care should be taken to inspect the rhizomes for evidence of borers before planting and the roots systems should be dipped into powdered sulfur or s 10% solution of household bleach.

To transplant iris rhizomes, the feeder roots should be planted about an inch deep; the rhizome should be at the soil level for best flowering.

Dig a deep hole to loosen the soil. Make a mound in the middle of the hole so that its top is level with the ground. Place the rhizome itself on the mound, and spread the feeder roots evenly around the rhizome at a slant. Fill the hole, firming the soil gently and water well.

Irises should be fertilized with a general-purpose complete fertilizer in early spring when new growth is just beginning, and in late summer or early fall to stimulate good root growth. Broadcast the fertilizer around the perimeter of the root system to side dress; don’t put the fertilizer directly on the rhizome. Always water before and after fertilizing.

The iris borer is a major pest of iris. They are the large pink larva of a cutworm moth, they are one –two inches long, and they will eat cavities into the rhizome. The foliage of plants infested with borers may have dark streaks, water soaked spots and/or ragged edges. Affected plants or rhizomes should be dug and discarded as soon as damage is detected. Affected areas of the roots should be removed by cutting them off and discarding them. Cleaning up plant debris throughout the year is a critical sanitation method for controlling iris borer. An additional complication of the iris borer is that the damage will provide an opportunity for the soft rot fungus to enter the plant. Soft rot will turn the rhizomes mushy—and VERY smelly!

To control iris borer and soft rot, good sanitation at the end of the growing season is a must. Clean up and remove all leaves in the fall being careful not to damage the root systems as you work. This will remove eggs that will otherwise overwinter and hatch in spring to infect plants.

Irises are also affected by a Botrytis disease, which is dry and odorless, but will prevent the plants from sprouting in the spring. Plants are also sometimes affected by leaf blight, leaf spot, and rust, but these diseases usually don’t warrant control. Water the soil, not overhead to control outbreaks of leaf disease and remove affected leaves as they appear.

Other members of the iris family that provide garden interest are the crested iris (Iris cristata), Siberian iris (Iris sibirica), and Japanese iris. Yellow flag (Iris psuedacorus) and Japanese iris (Iris kaempferi)
Will tolerate partial shade; these as well as the Siberian iris will tolerate wet soils, so they make great additions to your water garden edges.