Two American bloggers, Pat Sutton and Debbie Roberts, at Native Plants & Wildlife Gardens, have started a Plant This, Not That series, to promote using native plants rather than invasive aliens. As this is exactly what I was doing a couple of weeks ago here, promoting maple-leaved viburnum, I have decided to take up the challenge posed by Sutton and Roberts, and write a Southern Ontario edition of Plant This, Not That.
Golden ragwort (Senecio aureus, syn. Packera aurea), my overlooked and under-used native plant for this post, is a wonderful little flower I would like to see used in many more gardens. I propose it as an alternative to the European garden flower, leopard’s bane. In this case, it is not because the non-native replacee is nasty. Leopard’s bane is not invasive in my area; in fact, I’ve never seen it as a garden escapee. It is just that the native golden ragwort has a role to play as a host plant for insects, is just as pretty, and has no downside as a garden flower. Why not plant the native?
Yellow daisy flowers, in one form or another, are so very abundant in late summer, such an important part of so many plant communities in eastern North America, that any one planting a butterfly or wildlife garden inevitable plants at least a few: towering silphiums, sunflowers, varied and beautiful goldenrods, coreopsis, heleopsis. There are even yellow species of purple coneflowers. The bees and other pollinators of late summer must really like yellow daisies. Yellow daisies are much less common in spring. If one wants a cheerful yellow daisy to combine with tulips, garden centres will readily supply you with leopard’s bane (Doroconium). And that’s about it, at garden centres.
I used to wonder why anyone would want yellow daisies in their spring garden, so closely did I associate them with late summer and autumn. Delicate whites and blues, that’s what I wanted in spring. Well, that’s nonsense. There are many lovely yellow and bronze tulips, and golden yellow daffodils, and emerging foliage of spireas and bronze-hued young euonymus foliage and other lovely spring things in yellow. A cheerful yellow daisy that grows to about mid-calf might be just the right thing. Golden ragworts flowers are a bit more golden, individually smaller, than leopard’s bane. The deep purple stems and purple tones to the leaves are a definite asset. In the wild, it grows in moist sites, in ditches and at the edge of ponds. It will grow in ordinary soil in a garden, likes high, dappled shade or morning sun/afternoon shade.
After flowering, the original crown may die out and next year’s growth start on offsets a short distance (only an inch or two) away. Hence, do not deadhead hard until that process is well underway or the whole plant may die. Golden ragwort does not spread beyond its allotted spot in the garden, just shifts around a tiny bit. It will colonize damp spots, to very good effect.
Golden ragwort is a member of the genus Senecio, reputed toxic to herbivores. A scruffy-looking annual European species, common groundsel (Senecio vulgaris), is on noxious weed lists in European countries, because of its reputation for toxicity to horses. Our native Senecios are also full of harsh and bitter alkaloids to discourage herbivory.
Yikes! So, why would anyone want to plant something so unpalatable in a natural, wild-life friendly garden? Well, when plants and plant-eaters have evolved together for a long time, someone will find a way to eat it, by neutralizing or digesting the compounds. And when a species invests so much in utilizing a difficult food source, it often becomes not just possible, but necessary, for it to eat that plant. Just as monarch butterflies rely on milkweeds, there is a little lepidoptera that relies on native ragworts, the northern metalmark (Calephelis borealis). This rare butterfly is a weak flier which usually lives in open rocky areas where it is known to feed on the other native ragworts, round-leaved ragwort and balsam ragwort. The golden ragworts in your garden are unlikely to lure in northern metalmarks. Plant this flower for its bright blooms and enjoy it for its rightness in the landscape. There are doubtlessly other native insects, less studied and less known than the butterflies, which also eat this native.