10 Worst Plants to Grow in Your Yard

Ajuga Plants

Ajuga reptans spreads so vigorously as to disqualify it completely from landscape use. Commonly known as "bugleweed," this flowering groundcover may have a legitimate use somewhere, under some circumstances, but generally speaking, it spreads far too aggressively and is often incredibly difficult to eradicate.

Sweet Autumn Clematis

The first year one grows sweet autumn clematis (Clematis terniflora) in the yard, it can seem like a pretty sweet choice. Puffy floral clouds emerge from the mass of vines in fall, lighting up the fence, arbor, or stone wall. It will turn heads in the neighborhood, and you'll be sad when the blooms wave goodbye.

Then reality settles in during the next year. And the next after that. And...well, let's just say for an indeterminate period of time.

Sweet autumn clematis self-seeds, dropping a number of seeds in nearby soil, allowing it to spread all over the place. It will self-seed where you least expect it to, the seedlings lurking under the dense foliage of some shrub until you finally discover it one day while inspecting your garden. This game of hide-and-seek will take years to play itself out.

Trumpet Vines

You won't necessarily find trumpet vine (Campsis radicans) on lists of invasive plants. It is a North American native, and it's typically exotic plants that make their way onto such lists. But a plant needn't be classified as "invasive" in order to be aggressive. Trumpet vine is, in fact, a very aggressive spreader.

Nor is it alone in this regard. Another vine not classified as invasive in North America (where it's a native) but that is overly aggressive for small yards is Virginia creeper. There's another disincentive to growing the latter: it can give some people a rash (thus it doubles as a noxious plant).

White Ash Trees (Male)

There are some plants you may wish to avoid growing in your landscape if you have problems with allergies. White ash trees (Fraxinus americana) are dioecious. The male trees are among the worst plants you can grow in your yard if you're an allergy sufferer.

White ash trees can be beautiful in the fall. Remember, NUTS spelled backward is "stun," and some of these plants can exhibit stunning beauty. If you're not an allergy sufferer, white ash may be a wonderful choice for your yard. But if you (or a family member) tend to suffer from seasonal allergies, this beautiful tree should be avoided.

Tansy

Tansy is a poisonous plant if ingested, being toxic both to people and to livestock. Furthermore, like Virginia creeper, tansy is doubly undesirable, because it is also invasive. Tansy is not a good plant to grow around children, who may eat it when you're not looking and become sick.

Ginkgo Biloba Trees (Female)

Ginkgo biloba is a particularly troublesome tree, but only the female plant. Unlike the male white ash tree, pollen is not the issue. Instead, the problem with Ginkgo biloba trees is the fruit.

The dropped fruit is particularly messy to clean up, and the rotting fruit also emits an acrid odor that is similar to vomit. Consequently, this is not the type of tree you would want to plant near a patio or driveway, where you would have to worry about cleaning up the dropped fruit, or too close to the house, in the event you want to open your window to enjoy a fresh breeze. Ginkgo biloba is a great tree for your yard—if you stick with the male.

Large Lawns

Yes, a "lawn" is not a plant, per se. Large lawns qualify as troublesome because of the constant upkeep that they require. Of course, if you don't mind this upkeep, that puts the issue in a different light (no harm, no foul).

There is an alternative if you want one. Many suburban homeowners would be better off eliminating at least some of the lawn and using the freed-up space to enlarge flower borders, for example. Other gardeners may cite environmental or conservation reasons for ridding themselves of a traditional lawn. Depending on your climate, a rolling lawn requires a large amount of water to keep it lush.

Bradford Pear Trees

It's easy to see why people are tempted to grow Bradford pear trees in their yards. Not only do they offer a veritable blizzard of blossoms in spring, but they also furnish your landscaping with colorful autumn leaves.

But they have a fatal flaw: weak branches. You may end up losing your specimen to winter damage just after it comes into its prime—a disappointing turn of events, for sure. If you require extra disincentive to grow Bradford pears, note that they bear bad-smelling flowers.

Leyland Cypress

What's Leyland cypress' fatal flaw? Shallow roots. When these trees put on some height, they can be blown over relatively easily by high winds.

Combine that with the fact that the trees are susceptible to canker and it's easy to conclude that it may be best to stay away from Leyland cypress if you have a good alternative (arborvitae will be a good substitute for some folks).

Lombardy Poplar

People commonly encounter old Lombardy poplar trees (Populus nigra 'italica') that have "gone to pot." These can be real eyesores in a landscape. Like Leyland cypress, they are known for often coming down with a case of canker. The trees are short-lived, to boot.

Normally, when a plant starts looking bad, you can get rid of it. Not with this tree. The root systems, which are infamous for pushing up suckers, can be very difficult to eradicate. Those roots can also damage drainage systems. For all these reasons, the consensus is that Lombardy poplars are one of the worst plants to grow in your yard.