Chicago’s plant evals help us in Ohio

This past week I had the awesome opportunity to be on the same program with Richard Hawke, plant evaluation manager at the Chicago Botanic Garden, at the Michigan State University Extension Plants of Distinction programs.

I love to hear Richard’s presentations because he does an incredible job of plant evaluations at CBG. Regular readers of my column know how I believe in plant evaluations and the value.

I refer to Richard’s information all of the time when making plant choices for my garden as well as those that I use in my presentations.

The goal of these trials is to find superior plants for the Upper Midwest. If plants do well in the Chicago area, then I know that they will perform in Ohio.

There are four components to the CBG plant evaluation program: 1) comparative trials of herbaceous and woody plants; 2) cooperative evaluation projects; 3) green roof research; and 4) plant exploration to discover new plants (South Korea, China, Republic of Georgia and the United States and more).

The herbaceous and woody trials are the largest component. Perennials are evaluated for four years, vines and shrubs are six years and trees are watched for 10 years.

By looking at these plants over a period of time and comparing them to others in their category, Richard really has a great feel for plant performance. In some cases, the old, tried and true plants are top performers over the brand new introductions.

The green roof evaluation started in 2009. There is so little that we know right now about successful green roof plants and this research is really going to help make good decisions.

CBG opened a brand new building dedicated to plant conservation science that has a 16,000-square-foot green roof. There is at least 8,000 square feet dedicated to plant trials to determine which do best on a green roof. They are growing both herbaceous and woody plants.

The depth of the soil increases along the roof so that they can grow a better diversity of plants in the deeper soil.

In addition to plant evaluations, they have demonstration gardens to show how green roofs can be used. They are also monitoring the temperature of the air and the growing medium, moisture levels, ambient light and the heat transfer rate as well as wildlife that visits the roof.

If you are ever in the Chicago area, the CBG is a must-see for gardeners or if you just want to enjoy a respite from the city. If you can’t get to the gardens, then you can still learn about the results of the plant evaluations by going online to

Thank you for reading the Springfield News-Sun and for supporting local journalism. Subscribers: log in for access to your daily ePaper and premium newsletters.

Thank you for supporting in-depth local journalism with your subscription to the Springfield News-Sun. Get more news when you want it with email newsletters just for subscribers. Sign up here.