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Problem Plants to Avoid in the Garden

hybrid anemone

Hybrid anemone is one plant many gardeners regret having added to their gardens, because of its propensity for seeding around.

Text by Daniel J. Hinkley

In the autumn of 2012, along with a small band of volunteers and employees, I began the process of revealing the remnants of my first garden, Heronswood, which had lain fallow since 2006. Over the past three years, as a bit of shine has gone back on the acreage, we have garnered many lessons regarding the survivors, the losers, design errors and a few success stories. Above all else, however, I’ve been enlightened to what plants I would never, ever put in a garden again. What follows is a story about those plants that I, alone, unleashed into my garden beds and that I have now learned to loathe.

Hybrid anemones
When I first saw Anemone xhybrida in the early 1980s, I was entirely smitten. Sturdy stems stood erect to three feet, carrying masses of large pink flowers. I might have wondered why its gardener was removing such a beautiful thing at the zenith of its blossom, but off I went with the lusty clump and a great deal of satisfaction in having scored it for free.
During the years we continued to develop Heronswood as a garden and nursery, I gathered an impressive assortment of cultivars and wild collections of related species from Japan, China and Vietnam. They were the quintessential nurseryman’s plant: hardy, easily grown in containers, quite seductive in late-summer flower and eager to offer divisions for propagation.

It is the last of these attributes that now brings forth vile expletives as I discover yet another colony in the garden that demands expulsion. This plant does not play well with its neighbors, usurping entire beds and swamping virtually everything in its path, but for the taller of giant sequoias. It is its tenacity that is most troubling. You must abandon any notion that you will rid yourself of this thug by unremitting removal. Most gardeners will ultimately resort to glyphosate, only to discover it’s still no silver bullet. This is a plant that, once firmly established in your garden, becomes the tenant from hell. Be forewarned.

Certain hardy geraniums
While I was amassing a toxic arsenal of hybrid anemones, my attentions had also turned to perennial geraniums. By 2000, we were offering 85 different species, cultivars and hybrids through our catalog and, of course, these were planted in our display beds. Some remained polite, such as Geranium sanguineum, G. macrorrhizum and G. xcantabrigiense; they greeted us in 2012 within the same square footage they were initially allotted. Geranium xoxonianum, G. nodosum and G. phaeum did not. They’d thrown any concept of birth control to the wind, colonizing enormous sweeps of the garden in full sun as well as shade.

Removing an errant geranium from garden soil possessing even a modicum of tilth is not particularly challenging, but the genus is particularly talented in germinating in more problematic positions. They sling their ripe seeds to invariably germinate at the base of shrubs or within the clump of another perennial. One soon learns that a choice perennial or small shrub parasitized by a healthy geranium is as good as done for.

Though the colorful patterned-leaf forms of G. phaeum came relatively true from seed as they absconded with large sections of our woodland, the same faint praise cannot be said of any of the 12 cultivars of G. xoxonianum, but for ‘Katherine Adele’. Most reverted to things of little charm in flower or foliage. It will remain an ongoing chore to rid ourselves of this collection during the years (decades?) ahead.

‘Elstead’ St. johnswort
During one of our plant-buying forays to Europe in the early 1990s, I purchased Hypericum xinodorum ‘Elstead’, a shrubby species selected less for its yellow flowers typical of the genus as a whole and more for its colorful fruit. Indeed, even today, stems of this selection, or one close to it, readily appear as cut stems in florist cases, brandishing terminal clusters of handsome green, pink and red capsules. The vase is the only place this plant should be employed—and do not compost the stems after they go over.

Indeed, it became apparent soon after I introduced this species to the garden that it was too prolific in its progeny to consider retaining. We were making excellent progress in eliminating it entirely when Heronswood was shuttered in 2006. During the off years, a few returning seedlings grew to maturity, and the rest is history. Though young seedlings are relatively easy to remove, it currently is one of the worst offenders in the garden, even without having blossomed or fruited for three years.

Variegated (or any) butterbur
We long showcased big and bold plants in the garden for the extraordinary textural qualities they bring when juxtaposed with finer foliaged species. But Petasites japonicus ‘Variegatus’ has proved that the only thing possibly worse than big, bold and aggressive is big, bold, aggressive and ugly.

Known as fuki in Japan, where its stems are prepared and eaten like rhubarb, the species itself should be avoided in the garden at all cost. It spreads by stolons in moist or rich soils and it is extremely hard to eradicate once firmly established. The look of its yellow-streaked variegated form, which we planted along the edge of our pond in the late ’80s, makes this fact only worse. By midsummer, the foliage was scorched and seared, appearing as if we had been trying to kill it with herbicide long before we began deliberately attempting to do just that. The fanciful late winter “cones” of white flowers of this genus may rally interest from gardeners less wise; be advised that I do not know of a single species that deserves to be introduced into a garden setting.

Lesson learned
The late Christopher Lloyd once told me that dishing about plants he did not particularly like was often more entertaining to him than praising those he did. I must agree. Trash-talking on those plants one has come to regret including in the garden is a refreshing exercise—but try not to put yourself in the position of having the opportunity to do it.

Daniel J. Hinkley gardens at Windcliff, six-and-a-half acres of high bluff overlooking Puget Sound in Indianola, Wash. He acts as Director of Heronswood Gardens, today owned by the Port Gamble S’Klallam Indian Tribe, and consults with Monrovia, which markets the Dan Hinkley Collection.

Image credit: aimintang / iStock / Getty Images