July 2015 in the Garden

Summer is a time for flowers. Public displays of flowers help soften and add colour to planters and borders, and make people feel good. We are happier looking at flowers. But it’s not just our attention that flowers grab. Pollinators, thankfully, are also in the thrall of blossoms. Like people, pollinators have their floral likes and dislikes—although it’s probably better to characterize these choices in terms of biological imperatives—and a flower’s colour, shape, fragrance, as well as more subtle features, are a good way to predict how attractive it might be for a particular pollinator.

Much has already been written in this column about what’s attractive to hummingbirds in the Botanical Garden (tubular flowers in yellow or red, mostly), and while it’s an extensive and fascinating list, there are plenty of beautiful, even flamboyant flowers visited by other kinds of pollinators. There are even rhododendrons in the Asian Garden (e.g., Rhododendron auriculatum and R. glanduliferum) that normally flower in July. These species have large, trumpet-shaped flowers that mimic lilies in shape and fragrance, as well as in the nectar rewards that are so attractive to butterflies and moths.

Although not widely known, the tomato family has flowers that, while not always the most spectacular, are “buzz pollinated.” Buzz pollination, or “sonication” is used by a number of bees (but not usually honeybees) to shake pollen loose from a flower’s anthers (pollen sacs). They do this by vibrating their flight muscles as they rub against the anthers. In the Food Garden, bumblebees and other native bee species can be seen buzzing tomato, potato and eggplant flowers, and earlier in May, blueberry and cranberry flowers.

This is by no means the end of the story. Pollination and pollinators are important subjects in the Botanical Garden. While in the Garden this July and August, you may see Bailey Wilson, an intern from Niagara Parks Commission School of Horticulture, observing flowers and making notes. Bailey summer project is to establish a baseline inventory of native pollinators in the Botanical Garden.

Article submitted by Douglas Justice, Associate Director, Horticulture and Collections, June 30, 2015.

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