Plant This, Not That
Robin Schachat
Commonly when we think of endangered species in North America, we might think of Polar Bears; when we think of extinct species, we imagine the Ivory-billed Woodpecker. But plants fall into these categories also. According to the website Gardenia, the US Forest Service estimates that invasive species have contributed to the decline of 42% of US endangered and threatened plant species, and the extinction of up to 18%. “They displace and alter native plant communities, degrade wildlife habitat and water quality, and potentially lead to increased soil erosion. The federal government has estimated that nearly 25% of the 20,000 plant species native to North America are at risk of extinction, many of these through habitat loss….”
I have just finished reading an article online on “Treehugger”, a sustainability e-newsletter, and it prompted me to revisit the subject of “DON’T PLEASE PLANT THAT, but you could always plant THIS instead.” In this article Elizabeth Waddington, a published and well-respected garden designer, recommended using comfrey as a “cut and scatter” garden plant to enrich soil fertility. In all fairness, she does recommend using a little-known, sterile cultivar of Russian comfrey, Symphitum x uplandicum ‘Bocking 14’. Having lived through the past year of Covid variants, however, we all know that living things such as viruses and yes, even plants sometimes undergo spontaneous genetic changes that create new versions of themselves, and I cannot recommend at all scattering a highly invasive, non-native plant like comfrey in your garden.
Symphitum officinale is the botanic name of the garden plant commonly sold as Comfrey, and it is native to Europe and Asia. It is one of the parent plants from which the Russian Comfrey is derived. It is listed in the Invasive Plant Atlas of the United States. Comfrey blooms in late spring and early summer with clusters of bells of various shades of pink, purple, and lavender/blue. It grows quickly to 2’-3’ tall by the same width. It has historically been used in a number of folk remedies, and was imported to North America in the 1600’s for these purposes, following which it spread rampantly across most of the United States.
One obvious native alternative is Andersonglossum virginianum (formerly Cynoglossum virginianum) – obvious because it is also a member of the borage family, and has sometimes been called Wild Comfrey. It is at risk in most of its natural habitat, the eastern U.S., and is presumed extinct as of at least 20 years ago in Ohio, having been crowded out by various invasives including the much more thuggish true Comfrey. It blooms at the same time of year, primarily in woodlands, with small, bluish, five-petalled flowers. You will probably not be able to find it for sale; I suggest instead considering the following native spring bloomer.
Mertensia virginica, Virginia bluebell is also a member of the borage family, and grows to a smaller size, 1’-1.5’ in height and breadth. This Mertensia and its native cousins bloom in the color range of Comfrey blossoms, with a greater tendency toward true sky blue, in the spring. Mertensia is often seen as a spring ephemeral here, fading back underground in summer to emerge once again in March. Like Andersonglossum, it is a native woodlander, and is often best interplanted with later perennials such as asters that will expand later in summer to fill the blank spot left after Mertansia’s foliage fades away.
While sitting in a sunny window admiring the snowy outlines of your garden and dreaming of daffodils this winter, consider checking the characters of the plants you contemplate adding to your beloved space. Check the natural origins of the beauties you have fallen in love with, as well as their good and bad habits, their known pests and diseases, before you succumb to the delectable photos and descriptions in the catalogues that crowd your mailbox in January. You’ll thank yourself later.