Corydalis lutea (Zones 5 to 8) takes over as the walk makes its way into the shade of overhanging plum and maple trees. It has made an ever-expanding colony in the dry, shaded nook beside my front stoop. Its 1-foot-tall mounds of airy gray-green foliage are sprinkled with cheerful yellow flowers that light up their gloomy corner from March through August.
Lady’s mantle (Alchemilla mollis, Zones 4 to 7) crops up under rhododendrons, maples, and magnolias where it makes spreading mounds of soft, scalloped foliage and clouds of chartreuse-yellow flowers that seem to blend with anything. I have yet to find a self-sown seedling in a where place I didn’t like it. Equally useful and prolific is Geranium nodosum (Zones 4 to 8). This modest plant is less conspicuous in flower than some other cranesbills, but its soft lilac blossoms have a beauty all their own. The combination of the blossoms, the handsome glossy foliage that turns bright scarlet and orange in the fall, and the plant’s tolerance for dry shade make this a formidable ground cover indeed.
My use of vagabonds to liven up container plantings began when I discovered seedlings of the prolific annual love-in-a-mist (Nigella damascena) sprouting beneath roses in a decorative pot. ‘Miss Jekyll’ is an especially lovely blue-flowered Nigella selection that seeds true and provides frothy foliage, delicate flowers, and decorative seed pods as it skips effortlessly from container to container.
Geranium nodosum: This cranesbill geranium adapts well to dry shade, and its modest lilac blooms have a beauty all their own.
Nigella damascena: Love-in-a-mist offers frothy foliage and delicate blue flowers. The author encourages this annual to take up residence in his numerous container plantings.