The Garden's plant exploration program provides critical information in the worldwide effort to protect and preserve plants, while benefiting from their remarkable and diverse qualities.
Since 1984, Garden curators and scientists have made plant-collecting trips to the Republic of Georgia, Russia, Korea, China, Japan, Germany, Hungary, England, and Wales. Garden scientists have also made domestic trip to New York, Pennsylvania, New Jersey, South Carolina, Georgia, Florida, Alabama, Texas, Kentucky, and Arkansas. The Garden is a participant in two plant-collecting groups—the North American Consortium for Plant Exploration in China (NACPEC) and the Plant Collecting Collaborative (PCC). Through these consortia, we participate in both foreign and domestic collecting trips.
Collecting sites are carefully selected, based on a scientific review of environmental factors that can influence the success or failure of plants from other regions and countries here at the Garden. In this quest to identify the best sites, Garden staff analyze a number of factors, including the following:
- Precipitation patterns (annual quantity and seasonality)
- Temperature patterns (seasonal averages, highs and lows)
- Ecosystem similarity (deciduous forests, grasslands, etc.)
- Diversity of flora
- Soil pH and composition
- Length of growing season
The collecting expeditions have many purposes, including the acquisition of seed for ex-situ living plant collections; collecting herbarium vouchers; collecting critical data (latitude, longitude, elevation, etc.); and photo-documentation of plants and plant communities, as well as building long-term relationships with local partners that might result in staff training, staff exchanges, etc.
While discovering plants of horticultural merit is primary, Garden expeditions also provide plants of other interest, such as medicinal plants for study by ethnobotanists; rare and endangered plants studied for conservation purposes; and food plants, such as wild apples and English walnuts. Sometimes a plant's usefulness isn't apparent until years after it has arrived at the Garden; a timely example is four foreign-collected ash species that may prove resistant to the emerald ash borer. This exotic insect pest has destroyed more than 30 million native North American ash trees since first being observed in 2002. No North American native ash seems resistant, but these foreign ash species hold promise and may provide clues to developing resistance to this devastating insect. In time, the foreign ash trees or their progeny may substitute for the susceptible native ashes in our urban landscapes. Ex situ collections of plants collected from around the world are becoming more and more important as plants in this nation's habitats become rarer and rarer.
When the seeds are brought back to the Garden, they are evaluated for potential invasiveness in the garden through protocols established by the invasive plant committee. Plants that might have the potential to be noteworthy garden plants are trialed in the Bernice E. Lavin Evaluation Garden. Plants with superior or unique ornamental attributes are used by the Garden's plant breeding program or commercially introduced through the Chicagoland Grows™ plant introduction program. Plants deemed ornamental are also incorporated into the permanent display collections.