Illinois arboretum workers search for urban Supertree

LISLE, Ill. -- It may not be faster than a speeding bullet or more powerful than a locomotive, but Supertree has its own secret powers.

It can withstand blistering cold temperatures, attacks from its nemesis, road salt, and it doesn't show up everywhere like the honey locust.

Unfortunately for desperate gardeners needing rescue, Supertree is still a work in progress. But with continued study and cooperation between the government and the private sector, Morton Arboretum is hoping to provide the Illinois public with hardier and more varied trees than those available now.

The arboretum's latest developments toward that goal are two new outdoor laboratories, one on the Morton grounds and a second along the Eisenhower Expressway.

Arboretum research horticulturist Abbas Shirazi is heading up both endeavors.

"Our research will yield practical, real-world findings that will make cities more livable," he said.

A mile-long stretch along the north side of the Eisenhower is home to an experimental patch of trees that include varieties of lilac and magnolia.

"Lilacs have very good potential," he said. "We're testing new ones to see if they're salt-resistant."

Shirazi's branch of study is called urban horticulture. Its aim is to produce trees that survive the stresses of Midwestern urban areas. These stresses include salt, compacted soil, alkaline conditions and tough winters.

Shirazi works with plants developed by specialized nurseries, and he puts them through rigorous tests to measure their stamina.

Expanding research

This fall, Shirazi will expand his research area to a six-acre site on the west side of the arboretum. It will be planted mainly with Chinese elms, maples and conifers that will be studied for their tolerance to heat, cold and limited growing space.

Another aspect of Shirazi's research occurs at his indoor lab. There, saplings are slowly frozen to minus-40 degrees, shaken to remove water from them, and slowly reheated.

"We try to give them as much stress as we can," Shirazi said.