The three-part Garden Design Lecture Series, co-sponsored by the Belfast Garden Club and the Belfast Free Library, concludes Tuesday, March 13 at 6:30 p.m. with a slide show and talk by William Cullina, executive director of the Coastal Maine Botanical Gardens in Boothbay.

Cullina, also a well-known author and recognized authority on North American native plants, will offer an illustrated talk titled, “The Botany of Design.” Using his latest book, “Understanding Perennials,” as a starting point, Cullina tackles the thorny subject of garden design.

He explores such things as the reasons for big leaves, variegation, red foliage and flowers and ways to create more satisfying designs without breaking the budget. He looks at life beyond the color wheel, the importance of healthy soil and reveals some of horticultural secrets while weaving together aesthetics, psychology, botany, and ecology into a one-hour presentation.

Cullina lectures around the country on a variety of subjects to garden and professional groups and writes for popular and technical journals. His books include: “Wildflowers,” “Native Trees, Shrubs, and Vines,” “Understanding Orchids,” “Native Ferns, Mosses, and Grasses,” and most recently, “Understanding Perennials,” published in 2009.

Cullina and his wife Melissa live with their three young children on Southport Island along the central Maine coast.

Bella Bookstore from Belfast will be at the program with books available to purchase for signing.

This program is free and open to the public. For more information, call the library at 338-3884, ext. 10.