This spring a tall, thick old hedge surrounding the Hedge Collection at The Morton Arboretum in Lisle was replaced with new plants that, for the time being at least, are much smaller. That change led Landscape Architect Susan Jacobson and other Arboretum staff to create a pair of new, more open beds at the western end, framing an iconic vista down the long, formal garden.
But they had to stop and evaluate the site first, Jacobson said. "The removal of the old hedge really changed the way the light fell," she says. "And the trees nearby had grown, casting more shade."
The new design complements existing beds nearby, using many of the same plants in a simplified palette. Fewer kinds of plants are used in bolder sweeps of color and texture.
A public landscape such as the Arboretum has a priority for a highly visible spot: The plants must look good every day, so they need to be long-blooming and not fussy, with interest throughout the season.
The two flanking beds feel balanced and symmetrical, as fits a formal garden, but they aren't exactly the same. Because tall trees mean the beds get different amounts of sunlight, they are suited to slightly different arrays of plants, chosen to repeat and mingle textures, shapes and bloom colors.
For example, the north bed — which gets slightly more sun — has 'Blue Hill' sage (Salvia nemorosa 'Blue Hill'), while the south bed has 'May Night' Balkan clary (Salvia nemorosa 'Mainacht'), more widely known as 'May Night' sage. To the north is an ornamental onion, Allium tanguticum 'Summer Beauty', with lavender summer flower balls and glossy green leaves; across the way is a related kind of chives, Allium schoenoprasum 'Pink Giant', with soft blue-green foliage and pink blooms.
Meanwhile, some plants — such as a catmint with lime-green foliage (Nepeta 'Limelight') and Korean reed grass (Calamagrostis brachytricha) — are used in both beds to tie them together into a harmonious frame for the view.
"Sometimes you don't realize how much things have changed over time," Jacobson says. "So it's nice to have a reason to revisit it and try new things."
Beth Botts is a staff writer at The Morton Arboretum in Lisle (mortonarb.org).