A mail-order nursery catalog I recently browsed is touting Trachystemon orientalis as the plant for problem areas of the garden where other plants would struggle. They say it will rapidly cover blank or weedy areas in the garden, whether they are sunny, shady, wet, or dry. What can you tell me about it? It sounds intriguing, but I’m worried it might be invasive!
Trachystemon orientalis is in the same family as borage (Boraginaceae), with similar blue flowers and rough leaves (to my eye, it’s a plant for a wild garden, with its resemblance to borage and comfrey). According to Perennials by Roger Phillips and Martyn Rix (Firefly Books, 2002), it is a native of eastern Bulgaria, northern Turkey, and the western Caucasus region. It is naturalized in parts of England. The authors say it thrives “in wet beech forest on shady river banks and on damp rocks at up to 1000 meters, flowering in March-May.” It spreads by rhizomes and is tolerant of neglect. Its preferred site is moist shade, but it adapts to a wide variety of conditions, and excels at smothering weeds. There is additional information from Missouri Botanical Garden.
You may be right to wonder when a plant seems to be just the thing for almost any spot, and when it is promoted for its ability to spread easily. Some ground cover plants hover on the brink between covering the ground you want covered, and exceeding those boundaries. Trachystemon‘s common name is Abraham-Isaac-Jacob. The origin of that name is unclear, but my interpretation is that a plant named for the patriarchs of Genesis has a connection to generational continuity, a fitting name for a plant which is skilled at self-propagation!
See garden writer Margaret Roach’s blog post entitled “A Plant I’d Order,” and notice what she says about the likely behavior of this plant in the Pacific Northwest.
Trachystemon orientalis is included in the Manual of the Alien Plants of Belgium and
is listed in the Invasive Species Compendium. You could test its behavior in your garden for a season or two, and if it shows signs of aggression, you should still be able to eradicate it. If your aim is to be cautious, you may want to avoid planting it.