How We Thwarted the Old Well-established Oriental Bittersweet

I worked with my arborist first to dig out the plants at their source. 6 plants had been put in decades earlier at the base of each of 6 fence-posts. We dug down over 3’ deep and pulled up thick old roots. We removed the old soil. Then we covered the area near the base of the fence posts, where some bits of old roots probably lurked, with patches of black plastic. On top of this we placed landscape fabric, then over 3’ of fresh compost and leaves. Above this we placed another layer of landscape fabric, then cut holes in the fabric for the Arborvitae roots which sank happily into 36” of fertile, unobstructed soil. We topped it all off with 3” of mulch. Voila, only young seedlings appeared in my yard thereafter.

The neighbors were happy with their new improved landscape and watered it carefully and the Arborvitae all survived and started to provide a well behaved backdrop above our shared fence. Some of its offspring continued to grow in the less frequently tended yards of his two next door neighbors—I noticed these vines climbing their trees. But the constant maintenance in my yard kept it at bay. I for one, have no trouble deeming this noxious invader, a highly ranked invasive, a weed.

For the most part, difficult to remove plants may become weeds in your garden…

EXCEPT

Choice plantings of tall, thick, mature Trees are hard to remove too. Once they’re tall and thick enough you need an axe or chain saw to fell them, if you have no neighbors. If you do have neighbors, unless you don’t mind climbing while holding a revved up chainsaw, you need a climbing arborist to carefully remove top growth first and then chainsaw his way down to the base. A stump grinder helps to remove old Tree stumps and their roots. For big Tree jobs, even a renowned HGTV/ DIY TV gardener hires outside help. Tree pruning firms have cherry picker attachments for tall jobs, long and extendable handled snips, and skilled climbers with special equipment and a daredevil spirit (and hopefully insurance) who enjoy dangling suspended from ropes with sharp tools and whirring chainsaws.

Several vigorous spreading cultivars can also become tough to eradicate. Just a very few examples include: Black eyed susans, Rudbeckia, Hardy ageratum, Eupatorium coelestinum, Bee balm, Monarda didyma, perennial herbs like Dill and Oregano, and Gooseneck loosestrife, Lysimachia clethroides. (consider the name, it can loosen up a fair amount of strife on other struggling plants)

Above: Rudbeckia with deep spreading rhizomes became rude in a mixed perennial and Rose bed.

Left: Gooseneck loosestrife has tough deep roots and takes over Right: Hardy ageratum too, does the same

Above I listed groundcovers that grow too extensively under the title “when good plants go bad”. These include: Bugleweed, Ajuga reptans, Evening primrose, Oenothera speciosa, Star-of Bethlehem, Ornithogalum umbellatum, Lamb’s ear, Stachys byzantina, Lily-of-the-valley, Convallaria majalis, and Sweet woodruff, Gallium odoratum.

Left: Oh no, too many Oenothera near Roses Right: Lamb’s ear, in the Mint family, can spread fast