In a yard in which I’ve been puttering and landscaping for nearly twoscore and ten years, I finally must admit that there are a couple handfuls of flora that I wish I’d never planted or passively allowed to colonize. This realization was thrust upon me as two recently deployed military sons decided to settle back in Little Rhody, both within two miles of the family homestead.
Abby and I never expected such good fortune from the soldier and sailor who had truly traveled the world and seen and done lots of interesting things. The boys and their wives have nice, neat yards in which their young daughters can play. These yards are more or less blank slates, as mine was at one time, and I have been challenged to come up with planting plans (somewhat cautiously by one boy and a bit more enthusiastically by the other).
Though honored and flattered to be chosen to help with such extensive landscaping, I am also slightly intimidated. I don’t want to mess up. Mistakes that I made in my yard are my mistakes. Mistakes that I may make in their yards are also my mistakes. But there is a big difference.
That awareness initiated some extensive reflection on my part and as a result I have come up with a list of plants to be dealt with cautiously. I must say that there are good reasons for some people to choose most of these plants for some locations. And sometimes, these plants do not lead to negative outcomes, or at least they don’t do so for a very long time. (There is so much gardening knowledge to be passed on to the next generation—and the next!)
So below are my “plants of concern.” I would not grow them in my yard if I had it to do all over again. I recommend that anyone who wishes to use them do additional research and then try to envision how these plants may develop as they grow and mature in their own yards.
1. English ivy (Hedera helix)
I loved the look of this creeper in the Georgetown (DC) and Alexandria, Va., neighborhoods that I used to walk. I got my first pretty little pot of ivy as a bank promotion for a new branch office that opened near an Ivy League university.
I’ve since concluded that I like English ivy much better at someone else’s house than my own, where I struggle to control it. It has covered trees and infiltrated the lawn, though thus far I have kept it from adhering to my brick and stonework. Native to most of Europe, it roots (too) easily and when the stems become woody the almost tree-like plant also produces seeded fruit that birds drop all over, resulting in seedlings. If I falter and fail to actively restrain or prevent new ivy growth, I am doomed. My house could possibly soon appear to be just a giant mound of ivy.
2. Burning bush (Euonymus alatus)
In the autumn this plant produces spectacularly red leaves in my part of New England. People would always comment on its beauty. I loved the look, but when they reached about 10 years old these magnificent bushes were producing way too many offspring. I considered them as the price to pay for gorgeous fall foliage until they started to infiltrate neighboring yards. They then had to go.
3. Norway maple (Acer platanoides)
These wonderful shade trees can live up to 250 years in their native European and Asian range, but they more typically make it to just 60 in North America. Thank God. Despite the fact that Stradivari reportedly chose the Norway maple wood for his superb violins and that my kids have made a passably good maple syrup from its sap, I don’t at all miss the last of these trees, finally removed from my yard because of rotted limbs and trunk.
This maple’s surface roots killed surrounding grass and shrubs and the thick October to November leaf carpet could fill Mack trucks even when mulched. The amusing little helicopter seeds produced by just two large Norway maples gave rise to millions of seedlings over the years, which I had to deal with. Millions.
4. Sweet autumn clematis (Clematis terniflora)
I was first seduced by this tropically perfumed, white-flowering vine one September on Nantucket. It was everywhere, seemingly rivaling the famous pink climbing roses as the island’s plant of choice. A native of northeast Asia, it was vigorously employed to cover eyesores like water meters, electrical boxes and ugly fences.
I ordered a small plant from a catalog and now it—and its offspring—are also doing a good job of covering ugly things. The downside is that the older vines are producing wispy white tufts that transport seeds everywhere on the wind, and the plant seems to be naturalizing in the area. This tendency, unfortunately, was not mentioned to me by anyone on Nantucket or in the plant catalog description.
5. Yellow groove bamboo (Phyllostachys aureosulcata)
I should have known better than to plant this, but I held an exaggerated opinion of my ability to control what I still think of as a beautiful yard specimen. An eye-catching bamboo grove is a great conversation starter. Eventually, however, explaining all the negative consequences of bamboo culture to interested listeners required the talk time expended by Fidel Castro for some of his legendary long speeches.
Simply, my bamboo went wild and truly would have taken over the yard. The final outcome: I did laboriously remove all traces of this member of the grass family by mowing it, digging up its runners and corms and poisoning it. But it was not easy.
6. Rose of sharon (Hibiscus syriacus)
When other blossoms are disappearing in midsummer, you can depend on this old favorite to reliably produce pink, white and lavender splashes of color right up until the first hard frost. You can also depend on getting many nuisance seedlings in your lawn and garden beds.
However, the US National Arboretum has developed seedless and sterile varieties that are pretty much identical to the older varieties. I am in my second year of experimenting with these introductions and I love them. Eventually I will use the National Arboretum–developed plants exclusively.
7. Bittersweet (Celastrus orbiculatus)
This was introduced in the United States in the 1860s as an innocuous-looking ornamental. I grant you it is a pretty fall vine, with its orange and yellow berries. Abby is the culprit who brought this well-known invasive into our yard. She took a craft class and made some terrific autumn wreathes for the front door and lamppost. But some seeds escaped, and you can guess the rest.
As odd as this advice will sound coming from my lips, buy some good-looking artificial bittersweet to entwine with your other fall wreath components. I have seen bittersweet vines get under shingles and siding and actually pry them up. They don’t call this plant bittersweet for nothing!
8. Black walnut (Juglans nigra)
I thought I would really like growing this tree, whose dark wood is highly prized by woodworkers. In fact, I did make several chess sets with black walnut and Norway maple wood I cut from large branches that broke and fell in my yard during a tropical storm.
Falling branches are a problem with black walnut trees, which also seem to overproduce heavy nuts that attract fat squirrels, perhaps contributing to so many broken limbs. And this tree is an allelopath, known to create a zone of growth inhibition around it, in which many other plants cannot survive or thrive. Handling the husks of ripe black walnuts will turn your hands black.
Considering that the shells underneath the husks are hard as rocks, and that the nutmeats are tasty but minuscule, growing this tree was not worth the effort for me.
9. Violets (Viola sororia, V. odorata, et al.)
These cheerful-looking flowers are a welcome harbinger of spring. Abby loves them and defends them at every turn. Not only does she enjoy looking at a carpet of them—their color matches her eyes—but she puts them in salads, candies them for birthday cake ornamentation and makes little bouquets of them to brighten the house.
On the other hand, I attempt to eradicate them, a difficult process because they are prolific seeders, have a waxy leaf coating that resists herbicide absorption and store a lot of energy in their rhizomes, which contributes to their ability to spread. I have resigned myself to the fact that violets will never, ever be vanquished by me in my yard. Score another one for Abby.
10. Blue Atlas cedar (Cedrus atlantica)
It’s beautiful as a spiky-branched young tree with those bright blue-green needles, but as this tree matures it tends to get a bit misshapen, especially on top. But the real problem for me was that a mature tree produces large male cones that release thick clouds of pollen, which covered my driveway and cars and gave rise to dry, hacking coughs.
11. Horse Chestnut (Aesculus hippocastanum)
I haven’t completely closed the door on this tree yet. I love its distinctive and showy spring flowers, reminiscent of candles on the end of each branch. But the leaves are prone to an end-of-season blight that causes premature leaf drop. And like the black walnut, this tree is a squirrel attractor. Given my epic battles with the rodent, this should be enough to disqualify it from being in my yard. But we’ll see. A little-known fact: During WWI and WWII, starchy horse chestnuts (inedible to humans) were collected, mashed and fermented into acetone for war-related industrial purposes, though not particularly efficiently.
Will my sons take my advice and not cultivate any of my gardening nemeses? Probably not. I didn’t take much of the same gardening advice at their age, either. I have come to understand that this failure to heed is how the gardening gods ensure that all plants “be fruitful and multiply.”
Image credits: Acer platanoides by Andreas Rockstein/CC BY-SA 2.0; Clematis terniflora by harum.koh/CC BY-SA 2.0; Phyllostachys aureosulcata by Leonora (Ellie) Enking/CC BY-SA 2.0; Celastrus orbiculatus by Plant Image Library/CC BY-SA 2.0; Juglans nigra by Nicholas_T/CC BY 2.0; Viola sororia by Joshua Mayer/CC BY-SA 2.0; Cedrus atlantica by jacinta lluch valero/CC BY-SA 2.0; Aesculus hippocastanum by Plant Image Library/CC BY-SA 2.0
