Bearded Iris Planting and Gardening Guide

Bearded Iris have orchid-like flowers. Nine to twelve buds are usually found growing on short side branches on each stem. Each blossom lasts about three days. Three upright petals are called standards. Three sepals hang downward and are known as falls.

Bearded Iris may have standards and falls of the same colour or standards may be one colour and falls a different colour. Principal Bearded Iris colours are lavender, blue, white, purple, rose-red, yellow, pink, brown and various combinations and blends of these colours. The beard is the fuzzy, fringed appendage above the falls.

Types of Bearded Iris
MDB (Miniature Dwarf Bearded) up to 8 inches
SDB (Standard Dwarf Bearded) 8 to 15 inches
IB (Intermediate Bearded) 15 to 28 inches
BB (Border Bearded) 16 to 27 inches
MTB (Miniature Tall Bearded) 16 to 25 inches
TB (Tall Bearded) over 28 inches

Where to plant Bearded Iris
Bearded Iris prefer a full day of sun but will grow and bloom well if given six or more hours of sunlight. The best time to plant is six weeks after the iris has finished the bloom season between late July and early September. This will ensure early root development. The bearded Iris is drought tolerant but will rot if too wet. Gardeners can avoid many problems by providing good drainage to protect the Iris from getting "wet feet". Don't plant in heavy clay or water-logged soil or in areas with automatic irrigation.

How to plant rhizomes

Make a shallow hole about twice the size of the rhizome. Take a handful of the soil you removed and make a mound of soil in the center. Place the rhizome on top of the mound and drape the roots down the sides of the mound. Press the rhizome down to ensure that it makes firm contact with the soil. Any air pockets can collect water and cause rot. When you fill the hole with soil, the top of the rhizome should be slightly covered. Remember that it is always better to have the rhizome too high rather than too deep.


Iris beds should be kept weed-free or flowering will diminish or cease entirely. Take care not to damage rhizomes.

Dividing your Bearded Iris
Clumps become crowded, resulting in reduced blooming after three or four years. Lift clumps six to eight weeks after flowering and separate. Soak the divisions in a 10 to 1 ratio bleach solution (i.e. 1 cup of bleach in 9 cups of water) to kill pests and diseases before replanting, or share them with other gardeners. Dry the rhizomes for a day to callus the wounds.

Mulching and Feeding
Mulch can be laid between clumps but not atop rhizomes or crowns. Avoid high-nitrogen fertilizers, including wayward lawn fertilizers. Feed with a little bone meal in early spring and again after flowering.

Rhizome soft rot is common in some varieties and in wet growing seasons. Areas of rot can be scraped out with a spoon with the plant still in the ground. Sprinkle the wound with a household cleaner containing bleach such as Comet. Leaf spot is prevented with a fungicide spray.

The dreaded Iris Borer
There is absolutely no need to banish this beautiful plant from your gardens just because of the Iris Borer! Keeping a clean garden is the first step in minimizing borer problems In late summer early fall, the borer moths lay their eggs on the iris foliage or on the foliage of nearby plants.

In the fall, cut back the iris leaves and remove them from your property if possible. This will reduce the nbumber of borers hatching next spring.

In the spring, watch for the signs of borer infestation. A sharp eye for borer entry holes allows some gardeners to catch the borer in the leaf before it travels to the rhizome (simply pinch them in the leaves). If the borer has chewed its way further down the leaf, it may be easier to remove a portion of the leaf than search for and destroy the borer.

Squirrel Damage
If you live in an area that has squirrels, chances are they will attempt to feast on a few of your newly planted rhizomes. I have come up with the perfect way that keeps the squirrels from gaining access to newly planted Iris.

To prevent the squirrels from digging up and eating your newly planted rhizomes, simply cut strips of chicken wire approximately 5" wide and 10" to 12" long. Form into a ring and secure, then slip it over your newly planted rhizomes. The squirrels may make an attempt to dig up the rhizome but will soon give up. Once the rhizomes are firmly rooted, remove the chicken wire collar.

If you have many potted up plants, simply spread chicken wire over the pots so the squirrels cannot get to them. (click images below to enlarge)