Some plants are controversial. That concept may sound funny to you if you are a non-gardener. You've been taught that it's topics such as politics and religion that are controversial, not plants. But, yes, believe it or not, in the gardening community, some plants stoke our passions, and folks get into heated discussions about their use. Plume poppy is one of them.
You either love plume poppy or you hate it. In this introduction to the plant, you'll learn why such a gulf exists between these two camps. But, first, let's take a quick look at exactly what a plume poppy is.
In botanical lingo, plume poppy is called Macleaya cordata (which has taken over for the older name, Bocconia cordata). The genus was named for Alexander McLeay (1767 to 1848), an entomologist. The species name refers to the heart-shaped leaf base.
Macleaya cordata is not a true poppy plant, because it does not belong to the genus, Papaver, as does Oriental poppy, for example. It does, however, belong to the same family (Papaveraceae, the poppy family) as do the true poppies. A cultivar of the plant is Kelway's Coral Plume.
Plume poppy is an herbaceous perennial, and its suggested growing zones are 3 to 8. Full sun is recommended in the North, partial shade in the South. Its most interesting features are its size and shape. A tall, slender perennial, the plant can attain the lofty stature of 8 feet or more. Yet it usually doesn't grow much more than 2 feet wide. That's why growers who are drawn to statuesque plants are naturally drawn to plume poppy. The plant begins blooming in early July in zone 5.
The namesake "plumes" are panicles of tiny, off-white flowers. While these panicles are reasonably attractive in their own right, some growers remove them to prevent seed production. That's because it's really all about the foliage with this perennial, despite the plant's common name.
Why Plume Poppy Is Risky to Grow
The main reason why some gardeners hate this plant is that it spreads too aggressively via rhizomes (by seed, too, in some cases). Indeed, it's invasive in warm regions. For example, it made the State Noxious Weeds List in Hawaii. But you don't have to live in the tropics to find yourself cursing this garden thug. If you don't have the time, energy, or capacity to check its spread (or forget to do so), it could get out of hand.
As a secondary objection, the FDA lists Macleaya cordata as a poisonous plant: The juice that comes out of it when crushed is toxic. If you've ever tried pulling up the plants, maybe you've noticed afterward that this liquid has stained your hand orange. Given its reported toxicity, it would be better to wear gloves when you're pulling up a plume poppy, just to be on the safe side. As is often true of poisonous plants, plume poppy has long been used medicinally by trained herbalists (in China, in this case, to which it is indigenous).
Playing Devil's Advocate
But some people do risk growing Macleaya cordata and may be justified in doing so. The explanation for this lies, partially, in geography and in soil composition. Regarding the latter, plume poppy will spread the most if given a well-drained, evenly moist, fertile soil. In some cases, depriving it of such a soil will slow its spread. And as to geography, it's generally easier to control plume poppy the further north you go within its range. If you live where it gets cold enough in the winter, you may simply need to dig around your patch of plume poppies a bit at the beginning or end of each growing season and remove the rhizomes threatening to invade nearby flower beds.
So if you're a hater of plume poppy and are scratching your head to figure out what in heaven's name could possess anyone to grow it, consider the possibility that that gardener you hear raving about the plant may live somewhere with a soil or a climate very different from yours. Assuming that you can keep this stately perennial under control, it does have some good points:
Regarding the leaf shape, some think of it as perfect for those mysterious Green Man decorations. The deep indentations along the leaf edge give it the look of an island blessed with a multitude of bays along its shoreline, beckoning in ships seeking a safe harbor. The color of the foliage is also of interest: bluish-green on top, with silvery undersides. Size matters, too: The leaves can measure 8 inches across. Besides the pure beauty of the leaves, the fact that their texture is coarse is another benefit, as they make it easy to create textural contrasts in the garden.
The overall stature of the perennial is helpful, as well, when designing creative landscapes. Plant a row of them to form a summertime hedge within a vast, flat expanse, to break up the monotony. Install some annual flowers in front of this row for more color. Few other perennials make such a bold architectural statement with stems and leaves, alone. And, despite being so tall, this sturdy customer doesn't need to be staked. Other tall perennials that could serve as substitutes (for those who want to avoid the risk of growing plume poppy) include:
This plant is tough all the way around. Within its USDA growing range, it generally survives even under less than ideal conditions with little care from you, other than perhaps receiving enough water during its first year. This toughness is a real selling point if you seek plants that don't have to be babied.
Finally, if you're among the legions of people on the internet these days voicing your concern over the shortage of honeybees, then put your plant selection where your mouth is and grow plants that the bees seek out. Plume poppy just happens to be one such plant.
The Bottom Line
Before you grow plume poppy, check around to see how easily controlled it is in your area. If the results of your research raise red flags for you, that's your chance to dodge a bullet. Discretion is the better part of valor.
If, on the other hand, you see a green light and decide to grow the plant, just remember that you're taking on the responsibility to keep it in check. It's when you let the plant get ahead of you that it becomes a problem. You'll also need to determine if your property is large enough; plume poppy isn't well suited to small spaces.
If you live far enough North, control shouldn't require a lot of work, but you do have to stay on top of it. Limit the spread of the rhizomes by digging them out, and pull any seedlings that emerge. Or, if you don't trust yourself to remember these tasks, try growing the plants in an area where the rhizomes will be contained, and remove the flowers so that no seed can develop.
Finally, consider location carefully before planting plume poppy. It doesn't play well with others, so it's not a good choice for mixed perennial flower beds. It would crowd out your other perennials if not controlled, and the rhizomes would become entangled in their root systems over time. Nor is it a good choice for the landscaping along a property line: You don't want it escaping onto your neighbor's property. This specimen plant works best used in a mass planting, as an accent, off to itself somewhere, perhaps up again the south wall of an outbuilding.