Friends and family who visit my garden when the Iris in bloom, often exclaim, “Aren’t these colorful! What type of Iris are they?” They are referring to the Siberian Irises, which are planted in long drifts above the bog garden path. Apparently, for all their graceful beauty, with flowers poised like resting butterflies on tall, reed-like stems, they are not truly known to the average gardener.
Many times in recent years I wonder if this type of Iris obtains all the attention it deserves. Not only are Siberians unsurpassed for delicate beauty when planted enrnasse, but individual clumps of them make excellent companion plant in the perennial border. They flower at the same time as the Tall Bearded varieties but for the most part are at their peak just -after- the latter has passed the height of’ bloom. When established they require less attention than almost any other perennial, and are virtually free from disease or insect troubles and make charming cut flowers. The original Siberian Irises came from Central Europe and Asia, where they grew as meadow plants. The present-day hybrids will do well in almost any type of soil, whether it is clayey or sandy, provided adequate amounts of humus are mixed into the soil and the drainage is good.
While they are not water loving (like the Japanese type) they will tolerate water better than Bearded Iris, and therefore can be used equally well in dry spots or beside pools or bogs. They thrive best in full Sun.
The preferred time for planting Siberians is late September. Where possible, it is better to buy small clumps or divisions of’ about five sets of leaves each rather than single roots. These Irises resent being moved, and if the subdivisions are too small they require considerable time to become established and may not bloom until the second or third year after planting. If the divisions, which you receive from a nursery, are very small, plant three or more of them, not more than two or three inches apart so that they will quickly form a clump. When planting Siberian Irises, always keep in mind that they show off to better advantage if left undisturbed for five or six years, so be careful to select the best spot for them before planting.
The roots of these Irises are long and fibrous, resembling those of other types of perennials rather than those of Irises. Accordingly, the roots must not be allowed to dry out at the time of planting. Be sure the hole is deep enough so that the roots can be spread out and the soil firmly packed around them to give anchorage. To minimize heaving, it is advisable the first winter to cover the newly set plants with light material, such as bark or some type of local mulch.
Early in the spring, the old withered foliage on established clumps of Siberians should be removed promptly by cutting it off close to the ground. This is quite necessary to give the young foliage a chance to make its growth.
Be sure that the clump is kept free of weeds.
Otherwise, grasses -particularly Crabgrass may get a foothold right in the midst of a clump of Siberians, pass unnoticed for a time, and easily become so firmly entrenched that it is hard to remove them without mutilating the clump. To help older clumps maintain their vigorous growth, a top-dressing of compost and manure may be applied in the spring or after flowering. Do not use lime. Siberians prefer a neutral or slightly acid environment.
Because comparatively little hybridizing has been done with Siberian Iris, there are not the many varieties to choose from at the local nursery than there are in other types of Irises. The range of colors, up to the present time, is more or less limited to various shades of blue and purple, white and purplish red. For the most part, these are cool, crisp, clear-cut colors much needed in the garden. Most of the modern varieties can be obtained for a 15 dollars or less, and it is better to buy three or more of one variety in order to make an effective clump. A good collection can be made up of the following varieties:
MABEL CODAY – Ruffled medium blue with white signal
ERIC THE RED-Wine color, the closest approach to red.
CAESAR’S BROTHER handsome deep purple, tall and startling.
SNOW QUEEN – Crisp white collected form of I. sanguinea imported from Japan in 1900.
LADY VANESSA – Ruffled red-violet falls standards and styles light wine-red. White signals. .
TEALWOOD – Flaring velvet purple, narrow upright foliage.
HELEN ASTOR -bright mauve pink.
by F. W. Cassebeer