Chameleon Plant: Looks Can Be Deceiving

Chameleons are a group of lizards with some distinctive features, including independently moving eyes, divided toes to grip branches securely, a sticky slingshot of a tongue to catch prey at lightning speed, and, notably, the ability to change skin color, with some species exhibiting shades of red, blue, green, and blue, to blend into the surrounding environment, all of which make the chameleon an endearingly quirky reptile.

Less endearing, perhaps, is its namesake in the plant world. The chameleon plant (Houttuynia cordata) is a member of the lizard's-tail family (Saururaceae) that is native to wet and swampy places in parts of eastern Asia. Hardy in USDA Plant Hardiness Zones 4 to 10, the species is not widely grown in gardens; what is commonly available for purchase is the cultivated variety 'Chameleon' or its synonymous varieties 'Variegata', 'Court Jester', and 'Tricolor'.

The species has deciduous, blue-green, heart-shaped leaves tinged with red, borne on reddish stems that emerge from fast-spreading underground stems (rhizomes). Tiny greenish flowers arranged on upright one-inch cylindrical spikes are held above three to five white petal-like bracts, giving the look of a single bloom. The overall height of the plant ranges from 9 to 18 inches, but the spread is indefinite unless somehow contained by the gardener. Houttuynia will grow in sun or shade, with a definite liking for moist to wet soils, and will thrive even submerged in a few inches of water. Drier, droughty soils are said to help curb its invasive tendencies.

The variety 'Chameleon', with its green leaves splashed in shades of cream, orange, red, and pink, is highly attractive and looks gorgeous in the garden. As with our friend, the lizard, its bright colors disguise its true intentions: 'Chameleon' shares the same invasive characteristics as the species; and, to add insult to injury, the splashy variegation tends to revert to all green, often the result of either warmer temperatures or deeper shade.

The chameleon plant hides its invasiveness by masquerading as a desirable, ornamental, perennial groundcover: "an invasive disguised as an ornamental" is how Margaret Roach describes it in her book A Way to Garden (Timber Press, 2019). You will not find Houttuynia listed in weed books or on most invasive plant lists, but you will find it included in gardening books and online sites about groundcovers, ornamental perennials, and aquatic plants. Granted, these references will caution the reader about its bad habits: "tenacious," "practically impossible to eradicate," "aggressive," "seriously invasive," "can suffocate any competitor," and so on. The only recommended way to grow it, if you simply must, is to ensure it is within a strong container or boundary from which its rhizomes cannot escape or spread.

In his book Herbaceous Perennial Plants (3rd edition, 2008), Allan Armitage mentions that Houttuynia reminds him "of mint in the way in which they invade, defying eradication and reveling in their obnoxious behavior." You may well already have some of these murky ornamental/invasive plants in your landscape. Besides mint, a few that come to mind are gooseneck loosestrife (Lysimachia clethroides), yellow archangel (Lamium galeobdolon), and goutweed (Aegopodium podagraria), but there are many others. Before purchasing any plant, do some research first. Margaret Roach states, "These days, every purchase I consider is preceded with a little online research about its reputation for bad behavior in my region – an essential cautionary step." Caveat hortulanus – gardener beware.

The best approach is not to introduce the chameleon plant or others of its ilk into your garden in the first place. But if you have already been beguiled by its variegated leaves or attractive flowers or have inherited its presence in your landscape, how to get rid of it is a question without an easy answer. Herbicides are not always effective, as any little section of a rhizome left untouched will grow again from dormant nodes. Covering with plastic is not always effective; the rhizomes will find their way to the edges and grow there. Hand-digging may work in the long run if combined with careful sifting of every bit of soil and if you keep at it year after year until either you or the plant is exhausted. Changing the site conditions – increasing sunlight and decreasing soil moisture – may work over time if it is feasible. Your tenacity must outlast that of the plant.

In a damp, shady roadside ditch near my home, an area that was once gardened but has now been left to its own devices for several years, Houttuynia (reverted to green) is currently battling for supremacy with lesser celandine, English ivy, and nettles. On the sidelines, Italian lords and ladies (Arum italicum) is starting its encroachment. All bets are off, but I think they will all maintain a foothold, endlessly jockeying for space with the ebb and flow of moisture and sunlight through the seasons.