| Plant of the Month - September, 2005 |
|
by Jeff Iles Arboretum Board Member Professor and Chair Department of Horticulture Iowa State University
Picea omorika
Graceful, elegant, and refined are but a few of the adjectives used to describe Serbian spruce (Picea omorika). Unlike the stiff and somewhat artificial uniformity of Colorado spruce, Serbian spruce (50-60' tall and spreading 15-25' wide) displays a softer side with its slender trunk, narrow and strongly pyramidal growth habit, short ascending branches, and interesting two-toned needles. Whether used singly or in a grouping, this member of the pine family always catches my eye and leaves me wondering why it isn't more frequently used in residential and commercial landscapes.
In its native haunts (southeastern Europe, specifically to the region formally known as Yugoslavia), Serbian spruce is usually found on limestone outcroppings at elevations of between 2,500 and 6,000 feet above sea level. And while most of Iowa bears no resemblance to the rocky slopes lining the Drina River, our cold and sometimes dry winters, and predominantly alkaline soil conditions make Serbian spruce feel right at home throughout much of the state.
What about pest problems? A fair and important question since insect pests and disease-causing pathogens have either limited or restricted the use of several important conifer species over the past decade or so. And unfortunately, but not surprisingly, Serbian spruce is not without its share of biotic problems. Spider mites can be problematic especially during summers featuring prolonged periods of high temperatures and scarce precipitation. But more disturbing is the realization that the bane of Colorado spruce (rhizosphaera needle cast) also can cause problems for Serbian spruce. Choosing sites with good air circulation and not crowding plants too close together are some of the best tactics for combating this fungal disease. Cytospora canker, another potential problem, rarely has been reported.
While groupings can be effective, I prefer to use Serbian spruce by itself as a focal point or accent plant. Consider the appeal of a lone Serbian spruce standing watch over a home in the country or suburbs. Imagine its dramatic contribution as a strong vertical element amidst a groundcover of annuals, herbaceous perennials, or low-growing shrubs. Or the textural relief Serbian spruce would provide amongst a sea of white pine or Colorado spruce.
Serbian spruce will grow practically anywhere as long as drainage is adequate, but the most impressive specimens usually are found on sites where trees are afforded some relief from drought and late afternoon sun. Specifically, eastern exposures where soils are typically cooler and relatively moist favor plant health more than south or west-facing exposures.
|
