Bill Cullina has a bloodroot plant from his mother — which she got from her mother.
"The amazing thing is that a little plant like this can potentially live almost forever," Cullina said last week during a talk about perennials at a Connecticut Horticultural Society meeting. "They keep reinventing themselves."
Cullina made clear that's one of the most satisfying things about perennials: They keep coming back. Gardeners grow attached to them. And they grow faster than a lot of woody plants.
But Cullina — whose most recent book is "Understanding Perennials: A New Look At An Old Favorite," published last year — showed perennials also face a daunting array of perils.
Cautioning the audience, "You may want to avert your eyes," Cullina talked about the drought that sapped many Connecticut gardens this year. His slides detailed the progression of damage: the loss of a plant's little root hairs, the way a plant wilts, and the beginning of regrowth below ground.
Drought exhausts a plant's food supply. So does getting through the winter, fighting off disease, flowering and setting seed.
Cullina offered the most persuasive reason why not to buy plants when they're in bloom: "If you're buying a plant in flower, you're buying the plant at its weakest point," he said. Better to buy before they flower, after they flower, or, he said, "pinch off the flowers, as hard as that sounds."
Autumn is a good time to buy plants, he said, because they have more food reserves at this time of year.
Cullina, who grew up in West Hartford, earned a degree in plant sciences from the University of Connecticut, specializing in landscape architecture and horticulture. He worked as nursery director and head propagator for the New England Wild Flower Society for 11 years, and since 2008, he has been director of horticulture and plant curator at the Coastal Maine Botanical Gardens in Boothbay.
His passion for botany and the inner workings of plants was leavened with a highly colloquial way of explaining things. Discussing how soil can help plants during a drought, Cullina showed a slide filled with sofas (yes, sofas), likening it to soil that has lots of spaces in between for water and air to circulate but that would dry out quickly. Finer soil would be more like a roomful of toasters — the air exchange is slower, and there are more places for water to accumulate. Clay soil — like a room stacked with computer paper — holds too much water.
The best thing to do, he said, is add organic matter. However, he said, "Bagged organic material is dead organic material." He prefers to use compost "that's still steaming; it's living compost."
In one of the numerous entertaining and illuminating slides and asides he shared, Cullina showed how a flower has adapted itself to fit the bumble bee that pollinates it.
"Bumble bees don't see very well," he explained, pointing out the large spots that the flower had developed to look like lots of pollen. That lures the bee in, and then inward-facing hairs on the flower — "like spikes for a rental car" — help nudge the bee deeper inside where the real pollen lies.
In another fascinating portion of his talk, Cullina delved into the defensive chemicals that plants have developed, including chemical distress signals they emit when they're under attack, which alert nearby plants of the same species to start bulking up their own immune systems.
And, more amazingly, these signals also beckon the insects that then might come to the plant's aid and attack the caterpillar that's attacking the plant.
William Cullina will speak at a Nutmeg Orchid Society meeting Monday at 7 p.m. in the Yates Community/Training Room at the Police Headquarters, 319 New Britain Ave., Unionville section of Farmington. He also will speak at a meeting of the Connecticut chapter of the American Rhododendron Society Tuesday at 7:30 p.m. at the Connecticut Agricultural Experiment Station, 153 Cook Hill Road, Windsor.
For more on Cullina, go to http://www.williamcullina.com. For more on the Coastal Maine Botanical Gardens, go to http://www.mainegardens.org.