A Quest for Clammy Azalea: Susko Journeys throughout the U.S. South

October 20, 2014

It’s early morning, before the sweltering heat of Florida in June has quite set in. Alex Susko steps quietly out of the back of the Dodge Caravan he has been calling home onto the sandy roadway. Machete in hand, clad in a pair of work boots, blue jeans, and a black oilskin hat, he scans the landscape slowly and methodically for any sign of his quarry. Halfway down along the sloping stream bank, he successfully finds his mark. Characterized by branching, dark green ovate leaves and clusters of trumpet-like pink and white flowers, Susko has located his next specimen of Rhododendron viscosum, more commonly known as Clammy Azalea.

Last summer, Susko (Horticulture ’13, Ph.D. Applied Plant Science) spent two months on a lone expedition collecting plant and soil samples in remote areas and national forests throughout the southern U.S. and Gulf Coast. Susko relied on historic herbarium records, advice from local residents, and his knowledge of the plant’s preferred habitat to pinpoint azalea populations. Susko’s research, advised by professors Stan Hokanson and Jim Bradeen, examines the ability of plants to adapt to various pH levels in soil.

“In Minnesota, we tend to have alkaline soils,” Susko explains. “That can really limit plant growth for the Ericaceae family, which includes plants like blueberries, cranberries, rhododendrons, and azaleas.” The goal of Susko’s research is to screen for, and eventually breed, plants that can thrive in a wider range of soil pH. Susko took samples of soil and leaves and mailed them to a USDA research lab where rapidly developing technology has made it possible to decipher sophisticated genomic data relatively quickly. He also sent cuttings back to Minnesota where they will be rooted for more testing at the UMN Horticultural Research Center. 

The result? Hopefully, azaleas for your home garden that are more robust and require fewer inputs because they are well-suited to native soils. You may already be familiar with U of M cultivars such as Candy Lights or Golden Lights. Susko’s work may contribute to the development of new cultivars, furthering the U’s rich breeding program and adding color to the northern landscape. Susko’s research has been made possible through generous support from the Hueg Landscape Arboretum fellowship, research grants from the Azalea Society of America and the American Rhododendron Society.