Those Darn Yellow Daisies

Talk to botanists and they’ll tell you that the world is full of DYCs.  Botanists don’t care about DC (a thorny place full of prickly issues), the DMZ (a borderline patch between North and South Korea that is no place to garden) or AC/DC (loud rock music is not good for plants).  But DYCs are both a source of amusement and puzzlement, because in botany, they are the damn yellow composites.

Composites are plants with two part, daisy-like flowers.  Each bloom consists of a center disk flower, which may be green, brown, yellow, black, or any other shade, and the “petals,” or ray flowers around the disk.  So far, so good, so why the swearing?  Because there are so many species of yellow composites and they all look so much alike.  A botanist’s street cred (even if she works in the woods) hangs on being able to properly ID a plant, and DYCs create mayhem and foolishness.      

Of the dozens of wild DYCs, a relative handful have found their way into cultivated landscapes.  Three of them are in bloom at our Demonstration Garden right now.  Oxeye sunflower (Heliopsis heilanthoides) reaches a height of three to four feet, has dark green, opposite, toothed leaves, and covers itself in yellow daisies with a yellow center.  Its minor faults – that red aphids find hanging out on the stems beneath the flowers an irresistible place to be, and that it self-seeds a little bit – should be overlooked in favor of its jaunty demeanor.  Ashy sunflower (Helianthus mollis) is less well known but deserves consideration.  It has blue-green, opposite leaves without teeth and similar yellow flowers.  Cup plant (Silphium perfoliatum) has higher aspirations, producing its DYC flowers six feet or more above the earth.  Its paired leaves encircle the stem, hence the common name.  Michigan lists it as an endangered native plant, while Connecticut calls it invasive, so go figure.  All three of these species, like most DYCs, will live happily for years in full sun to slight shade in a wide range of adequately drained soils.

If cup plant excites you for its stature, you’ll also love the towering cutleaf coneflower (Rudbeckia nitida ‘Herbstonne’), which reaches over seven feet.  Its ray flowers of an even more luminescent shade than most DYCs droop a bit and the disk is mounded and slightly green.  Double-flowered variants of this also exist, but the blossoms look like used Kleenex to me.    Most bizarre is Cabbage  leaf coneflower (Rudbeckia maxima), which shoots up seven foot leggy stalks, each topped with a single bloom of very limp rays encircling a big brown disk.  The base is a set of strappy, blue-green leaves which reminded someone of the main ingredient in cole slaw. 

Lest we forget the plant that swept the ‘1980’s, consider Rudbeckia fulgida ‘Goldsturm.’  With black-eyed Susan cheerfulness and Terminator toughness, it became the poster child for the “new American garden” school of landscape design, made millions for the nursery industry and thrives coast to coast.  Damn good for a yellow composite.