Purdue Extension Service

Vanderburgh County, Indiana

What's New in the World of Horticulture?

By Larry Caplan, Extension Horticulture Educator, Vanderburgh Co., IN

For the Evansville Courier and Press, January 27, 2008

Last week, I attended a series of "Green Industry" conferences in Indianapolis, to keep myself up-to-date on all the most recent research in turf, trees, and ornamentals. I definitely picked up a lot of useful information, which I will be able to use to better serve and educate consumer and commercial audiences in and around Vanderburgh County.

One fascinating seminar was on the subject of Organic Lawn Care. A growing number of homeowners want to "act green" and have less of an impact on the environment, while still having a quality lawn. We learned about some of the fertilizers and other products that are considered "organic," and their benefits and drawbacks.

With all lawn care programs, but especially in organic programs, the most important link in the chain is the homeowner: how much work are they willing to do to get a high quality lawn? We saw evidence that it doesn't matter what products the lawn company uses, or how dedicated they are: if the customer does not water the lawn properly on a regular basis, or mow at the right height, then there is no way to get a decent lawn.

Another intriguing seminar dealt with "green roofs". This is a practice of growing flowers, grasses, and other plants on the roofs of buildings. Research has shown that green roofs help reduce rain runoff from rooftops, meaning less water is flooding our streets and sewers. Green roofs keep our buildings cooler in the summer, warmer in the winter, and increase the lifetime of roofing materials (because they protect them from destructive UV radiation). Green roofs also increase the aesthetics of the community, and reduce the urban "heat island" effect, much as trees in parks do.

Before you shrug this off as something too weird for southern Indiana, consider this: Chicago's Mayor Dailey has been promoting green roof grants and awards programs for years, and Chicago's City Hall has a 20,300 square foot rooftop garden with 20,000 plants, including 100 shrubs, 40 vines and 2 trees. Germany has been working with green roofs for over 40 years, and has about 50 square miles of roofs landscaped. And the University of Georgia has several buildings with green roofs, dispelling the myth that our roofs here in southern Indiana get too hot for this to work.

A neat way to green up your roof without trucking up tons of soil was to use a light-weight modular planter box system. These planter boxes were self-contained, light enough for one person to carry it up a ladder, and mobile: if work was needed to be done on the roof, the modules could be shifted around without killing the plants. They even work on sloped roofs! A lot of the research presented was generated at Southern Illinois University in Edwardsville.

I'll be sneaking more of what I learned at the conference into future articles and seminarsoHor, but if you have questions, please contact me at the Extension office at (812) 435-5287.