Smitten with groundcover perennials: here’s how I’ve learned to help them thrive
At one point, I was surprised to discover that groundcover perennials can conquer not just their own area, but also the surrounding area, writes Liisa Häkli, Managing Editor of Kotona’s gardening content.
I’ve always been slightly smitten with groundcover perennials—they offer so many delightful leaf shapes and colors for the base of a bed. However, there are a couple of key considerations: you need to choose the right species for the right role, and if you pick the wrong one, realize that letting it go might be best. I was once surprised to find that some groundcover perennials can spread beyond their own patch and take over the surrounding area.
“Especially deadnettles and big-root cranesbill have claimed my garden as their own.”
In the partly shaded areas of my yard, yellow archangel and big-root cranesbill have proven especially assertive. I first kept yellow archangel in a container, where it overwintered without a hitch, but I had to remove it once it crept into the ground and began spreading alarmingly toward my neighbor’s border. Its relative, spotted deadnettle, wasn’t as pushy and added a pleasing glow with its pale leaves at the far end of my yard—until it, too, began creeping so vigorously that it crowded out its neighbors. Meanwhile, big-root cranesbill, a perennial that seems to thrive in practically any conditions, slipped under the fence and beyond my yard in just a few years. Even though I weeded it out nearly a decade ago, it still pops up here and there.
In addition to steering clear of overly unruly types, I’ve learned that success with groundcover perennials often depends on giving them enough space and setting clear boundaries. For instance, in my small yard, cranesbill ‘Biokovo’ forms a lush carpet beneath my ‘Lime Rickey’ smooth hydrangea, but it’s kept in check on one side by a bed border and on the other by the firmly rooted Japanese anemone 'Robustissima'. Under the rhododendron, I planted the leathery-leaved asarabacca, encircled by ramson, foam flower, and hybrid red barrenwort, hoping they’d hold each other in balance. Time will tell if one ends up dominating. Just in case, I’ve rooted some Japanese spurge cuttings—ready and waiting if there’s ever a need for a boundary-setting referee plant.
