I’ve arrived at that inexplicable place where I’ve forgotten the hassle and headache of eradicating Macleaya cordata, a colonizing perennial that once ran roughshod in the front garden, only to find myself once again considering adding it back into a border in another part of the garden.
This cycle, dumbfounding as it may be, is nothing new in my gardening life, but as regular as lunar cycles that pull the tide and were once thought to govern human behavior. Am I the only one who has only recently made the connection between lunar and lunacy? I digress.

Wouter Hagen via wikimedia
A useful thug
Plume poppy (Macleaya cordata) is a vigorous rhizomatous perennial, which is plant-speak for: This plant is a thug. I would add, a lovely, striking thug with a narrow profile and slender sturdy stems that grow 5- to 8-feet tall without staking.
Beautifully lobed sea-green foliage with a silvery reverse and panicles of pink buds that produce creamy white flowers that ripen to rusty plumes, lure admiring gardeners (like me) into thinking plume poppy would be ideal in a small garden (like mine). With proper siting, plume poppy creates a very serviceable seasonal hedge, providing a verdant backdrop to other resilient plants or it may be used to seasonally screen an unwanted view of the garbage cans or the neighbor’s garage. The entire plant dies completely to the ground in winter.

Denis.prévôt, CC BY-SA 3.0 via Wikimedia Commons
However, while all that loveliness is waving about in the breeze and providing a dramatic focal point in the garden, beneath the surface of the soil plume poppy is sending out rhizomes and irretrievably tangling with the roots of all your favorite perennials. While the plant won’t rupture your sewer or cause your sidewalk to heave, its colonizing ways can quickly overtake less sturdy treasures. Plume poppy does not play well with others of a more delicate growing temperament. No, this is a candidate for wilder corners of the garden.

Denis.prévôt, CC BY-SA 3.0 via Wikimedia Commons
Tough love
Macleaya cordata is a resilient plant that demands few inputs. Cushy garden conditions, rich soil, and ample water, encourage its wanton ways. Poor soil and moderate water curb the plant’s enthusiasm, as does deadheading blooms to prevent ripe seed from furthering its takeover. The plant is slow to emerge in the spring, but that’s the best time to control spread by removing unwanted shoots as they appear.
Given the right conditions in an appropriate growing region, this lusty plant is both a bold garden statement as well as a lesson in cultivating responsibility. Gardener, know thyself (as well as thy growing region and climate), and plant accordingly. What works in my garden may not be appropriate in yours.
The intended site for my future plume poppy is a rangy border where my grip is decidedly looser than in other more manicured parts of the garden. I call it the pollinator border, which sounds so much nicer than unkempt and neglected. Bordered by asphalt on one side and gravel on the other, beds in this metaphorical back forty are filled with beefy plants that bloom for an extended time. Rugosa roses, showy milkweed, Verbena bonariensis, ornamental grasses, and self-sowing annuals, hold their own with little intervention on my part.
With flowers that are rich in pollen and nectar, plume poppy provides valuable support for bees, butterflies, and other beneficial insects. I think it will settle in nicely rubbing shoulders (or, duking it out) with its neighbors.
Plume Poppy such a tough plant, it can take a lot of punishment. So in a former garden, I buried a galvanized can (about 18″ wide) with no bottom, leaving a good 3″ above grade, and planted in that. It contained the rhizomes quite effectively. About every third year, we’d pull it, dump the exhausted soil, and replant a chunk of rhizome. BUT: I made the mistake of burying the leftovers in a compost bin. Years of self-reproach ensued.
“i call it the pollinator border which sounds so much better than unkempt and neglected.”
Can I steal this? Perfect phrase!
Lorene, of course this is lunacy, but that has never stopped us from experimenting with dubious plants. I commend you for trying again in what you have possibly deluded yourself into thinking is a safe environment for this plant. My philosophy has always been that ‘everything is temporary’ and if it doesn’t work out you can just remove it. Just don’t make the same mistake Chris did. Some plants really need to go into the yard waste bin where they will be properly composted. Bishop’s weed and Houttyania come to mind.
“I call it the pollinator border which sounds so much better than unkempt and neglected.” I am concerned that this phrase promotes a negative stereotype of pollinator borders, which can be as formal as sterile borders.
I, on the other muddy hand, would love to get a patch of this growing again. I first enjoyed it in my New York and Connecticut gardens, where it was lovely and mannerly. Now I am in coastal northern California and cannot coax it Into being again. For a brief while, I had one struggling plume (decent soil, filtered shade in afternoon), now vanished. I have plenty of room for it to roam, but I think it no longer likes me, and I miss its height, glaucus leaves and the way they hold droplets of water,,not to mention the lovely plumes’ attention to wind. Sigh.
Many years ago, creating a new garden with delight and naivety in equal parts, a promising unknown little self seeder appeared….I fostered it, so handsome and made such a striking exclamation mark at the end of a border. Oh, how I wish I had had the benefit of your experience and the true knowledge of this ‘vigorous rhizomatous perennial’ – thug does not begin to describe it! Those truly ghastly rhizomes I came to detest …. but like you Lorene, I am secretly still in love with it but my new small surburban garden is never, ever going to host it!
How I love this plant! I live in a CT suburb, and this is in my front cottage-style garden, a lovely stand of it in front of the left end of the house, our former side porch that is now my husband’s study/man cave. I must confess to a love of garden thugs, and perhaps my plume poppy has remained pretty well behaved all of these years (decades?) b/c they are cheek to jowl with other thugs like bee balm, obedient plant, etc. Mine do lean forward a bit, maybe b/c they are shaded in the afternoon. It’s a difficult plant to stake, I would think. I remember falling in love with them when I read about them in a garden book so long ago. The author described their leaves as “shaped like some uncharted island in the ocean.” How could I not fall in love?
Having spent hours digging this thug out of a trial garden, I will never forget how miserable it made me and others who worked in the garden. Would recommend never ever planting it.