In a recent bygl-alert (https://bygl.osu.edu/node/944) I posed this challenge: More wicked (sometimes) plants this way shall come, culminating with Halloween, bygl alert-style. What are your candidates for the ultimate in plant wickedness? E-mail me at firstname.lastname@example.org.
Or at least spookiness of some sort. Here are a few of your responses:
1). Barbara Myers, Madison County Master Gardener responded: “My first and mostest top worst plant for the wicked plant list is Aegopodium. The variegated variety was on the east side of my house when purchased in 1974. It quickly reverted to all green and has moved to every bed in my yard. It is truly invincible and short of "Rounduping" everything, impossible to get rid of.”
Bishop’s goutweed, also known as snow-on-the-mountain or ground elder, Aegopodium podagraria, is indeed a non-native invasive (Europe and Asia) that is condemned for that which it does best, spreads to cover the ground, er, ah, acts as a groundcover. It does this via rhizomes (underground stems). It does this so well that a Missouri Botanic Garden Gardening Help note likens it to a “snowball rolling downhill”. Presumably down to – that other place.
They note that Aegopodium podagraria ‘Variegatum’, the most common form used to cover large areas indeed oft reverts to a green form. They recommend that those who still want cream-variegated goutweed after planting it and watching it spread should remove green forms immediately as they are more aggressive and less ornamental.
Aegopodium is a member of the Apiaceae, the carrot family (formerly known as the Umbelliferae). The name comes from “aix” and “podium”, the Greek for goats-foot; once used in some form as a treatment for gout. Leaves the shape of a bishop’s mitre, and the elder-name for resemblance to elder foliage. Just by devilish coincidence, my good friend, the famous Mike Lee (of Mike Lee’s Nearly Famous Dolgo Crabapple Butter), e-mailed me this morning that: “Your father smelled of elderberries.” And?
To conclude with confirmation of Barb’s angst: the National Park Service notes:
“Goutweed is an aggressive invasive plant that forms dense patches, displaces native species, and greatly reduces species diversity in the ground layer. Goutweed patches inhibit the establishment of conifers and other native tree species as well.”
The United States Department of Agriculture Natural Resources Conservation Service site lists goutweed in assorted invasive listings for Connecticutt, Massachusetts, and Vermont.
2). Ron Rothhass, President of Arbor Doctors, nominates several candidates for Halloween-ish status.
a). Amur honeysuckle.
“Planted on purpose for years in Cincinnati parks (years ago, before they knew better), it is now spreading like ripples in a pond, outward in all directions. It invades forests, smothers out native plants, and short circuits natural succession, culminating in an amur honeysuckle ghetto.”
The National Park Service site indicates that Lonicera maackii was introduced by the New York Botanic Garden in 1898, so Cincinnati parks were not alone in their plantings. Many non-native honeysuckles have indeed become problems, fueled by their prolific reproductive capacities and early season photosynthetic head start. Amongst their recommendations for management they indicate:
“Young plants can be pulled by hand, larger plants either pulled using weed wrench-type tool or cut repeatedly.”
And then there is the Amazonic capacity of Clark County OSU Extension educator Pam Bennett invading Greene County and Clifton Gorge to heroically pull out invasive honeysuckles.
b). Native Ash Tree Zombies.
“Way too many dead ash trees are still standing way too close to populated sites. Just a couple weeks ago an ash carcass fell on a wedding party in northern Kentucky, killing two in the wedding party. Not a joking matter. These standing dead ash trees are everywhere, a deadly accident waiting to happen. Making a good case for inspection by ISA TRAQ arborists.”
The problems with trees killed by pests is indeed serious, as Ron notes. Another example is in the U.S. West where the many millions of conifers killed by mountain pine beetle as its range spreads northwards has resulted in great hazards even for trained arborists charged with removals near highways and habitations.
c). Magnolia Vampires.
“OK, they're not really vampires, but magnolia scale insects do suck the life out of magnolias, and they have been numerous this year. To make matters worse, this attracts all manner of stinging insects. These vampires may actually be tended to by ants who see the scales as their sugar daddy tickets to a free meal.”
A veritable Hieronymus Bosch of entomological excess: not unlike the right panel of his Garden of Earthly Delights triptych: “a hellscape; a world in which humankind has succumbed to the temptations of evil and is reaping eternal damnation”, as described by a Wikipedia wonk.
d). Ghost of the Forest.
“I know Joe just did an article on buttonwood, but another common name for sycamore is Ghost of the Forest, owing to the stately, white, often lone trees standing out in the stark winter woods. That's one beautiful ghost! Not too many terrifying features but the name seems qualifying!”
Sycamore, Platanus occidentalis, sometimes precipitating oaths of a different sort from landscape and lawncare maintenance professionals as they clean up the fallen twigs and leaves, is indeed wonderful as well. And entering its prime season in wintry bone-structured plantscapes.
3). Gary Eichen of Mike’s Tree Surgeons nominates Colorado blue spruce.
“Saw your BYGL article, the "plant" that comes IMMEDIATELY to my mind (such as it is) is the Colorado Blue Spruce, Overused, over-planted, "over-everything! Pitch mass borer, Zimmerman pine moth, Cytospora canker, Phomopsis canker, Rhizosphaera needlecast, spruce spider mite. I'm sure I forgot 1 or 2. ALL a result of not being well-adapted to the upper Midwest's winter temperature fluctuations. Stress levels increase with age, causing significant drop in innate defense mechanisms (if it has them). Decline (disfigurement?) inevitable. I'm sick of: "What's the matter with my blue spruce?"..
Tell us what you really think, Mike. And, to add to your rant, here it is again, tricking the treat of a Lavender Twist redbud, stabbing, stabbing, stabbing. Oh, the redbuddery!
Well; Halloween is here. Now, to really scare you…
Joe is coming for you!