Plains Coreopsis Will Not Be Tamed
Plains Coreopsis is a reseeding annual. Seeds that fall to the bare ground in the early fall germinate into low rosettes. They stay there all winter, waiting for warm weather in early summer, when they suddenly sprout into four-foot-tall, delicate, airy plants. The new blooms start out as tiny orbs at the tips of the fine-textured foliage, and soon pop out in cheerful circles of bright color. Most have maroon eyes set inside yellow edges, but this can vary. Occasionally, a plant will be solid maroon or solid yellow, depending on the amount of bleed between the two colors. By mid-July the flowers have set seed, and hold their small, round seed heads until fall. Plains Coreopsis has a life cycle that starts in fall, rather than spring, like a typical warm-season annual.
When sowing seeds, be sure the ground is bare. Plains Coreopsis likes to start with a clean slate. If you let Plains Coreopsis reseed on its own, it will locate randomly, scattered in spots not covered by other growth. It likes newly disturbed areas more than established, static plots, so it will never behave in a typical ornamental perennial bed. The stems are so long and thin, it tends to droop badly with the weight of its open blooms, so it will need staking if you want to prevent it flopping to the ground. Bending over to gently drop seed is its way of moving to good soil where it can germinate on bare ground. The seeds don’t need to be buried in soil. They are content to sprout from empty ground. They will self-seed for a few years, declining in numbers unless you provide them with new spots and a change of scenery. Each fall I gather several dried plants full of seed heads and scatter them in various open, sunny spots, hoping they will choose to germinate in at least one or two areas.