When it comes to home gardening, knowing what not to plant is just as important as knowing what should be going into your garden.
At the Missouri Botanical Garden, we grow and study plants from all across the globe. With a team of scientists, we can grow, study, and contain even the most fickle or foreign plants.
For home and hobby gardeners, though, finding the right plant for your environment is crucial to not only have a thriving garden, but a garden that promotes the health and success of our native ecosystem. That’s why the Missouri Botanical Garden has highlighted Plants of Merit for the 25 past years.
Conversely, adding the wrong plant can hinder your garden’s growth, or you might even find yourself overwhelmed with a stubborn plant that keeps coming back no matter what you do.
The horticulturalists at William T. Kemper Center for Home Gardening have created this list of plants they suggest you avoid for your garden. Some entries on the 2023 Plants of Demerit list struggle to grow in the St. Louis conditions, while others thrive and become hard to control. And some are invasive and harmful to our natural plants growing here in Missouri.
Discover what plants our experts are avoiding, alternative ways of growing fickle plants, and native plants that you could substitute with.
Burning Bush (Euonymus alataus)
Though used often in home, business, and even along highways for its beautiful red color, Euonymus alatus, commonly called the burning bush, isn’t just fiery in name and color, but also in its ability to spread rapidly and cause damage.
This shrub produces berries that attract birds who help spread the seeds far beyond where the bush was originally planted. Because the plant can perform well in almost any environment (sun, shade, dry, moist), many of those seeds have a high potential to grow into a plant.
If conditions are favorable, this plant will will out-compete native plants to form dense thickets. Because of this, it has been branded a noxious weed in more than one Midwestern state. If you have this in your yard, you are highly encouraged to dig it out and get rid of it.
What to plant instead:
- wilder ginger (Asarum canadense)
- ladies’ tobacco (Antennaria parlinii)
- Robin’s plantain (Erigeron pulchellus)
Wintercreeper (Euonymus fortunei)
In the same genus as Euonymus alatus, Euonymus fortunei is another adaptable plant that can easily take over areas.
Commonly referred to as Wintercreeper, this vining evergreen can look like a ground cover but will take almost any opportunity to climb up a vertical structure if left unchecked. If that happens, the plant can then produce flowers and berries.
Wintercreeper has escaped cultivation and is considered highly invasive in much of the eastern United States where it smothers and out competes native vegetation.
What to plant instead:
- pussytoes (Antennaria plantaginifolia)
- barren strawberry (Waldsteinia fragarioides)
- three-leaved stonecrop (Sedum ternatum)
Bamboo (Phyllostachys, Pleioblastus, Pseudosasa, and Bambusa)
There are several species of running bamboo. Four genera include: Phyllostachys, Pleioblastus, Pseudosasa, and Bambusa. All should be avoided.
If the bamboo markets as “fast”, “fills in quickly”, or “privacy screen”, you may want to run in the opposite direction because once this plant is in the ground, it is an ongoing battle to get rid of it. Rhizomes of this bamboo will keep growing vigorously and spread anywhere it can.
Even constant mowing over the sprouts won’t get rid of it; the rhizomes are still connected to the existing shoots and will keep spreading the following year. In order to remove bamboo, heavy machinery is often required to fully dig out all the roots and rhizomes.
Having bamboo can lower your home value, start wars with your neighbors, and be a big headache.
What to grow instead:
- prairie dropseed (Sporobolus heterolepis)
- American beakgrain (Diarrhena obovata)
- giant cane bamboo (Arundinaria gigantea)
Chameleon Plant (Houttuynia cordata)
Chameleon plant (Houttuynia cordata ‘Chameleon’) is a gorgeous plant that will take over if given a chance, even if just a tiny cutting is planted anywhere.
It spreads aggressively and many people innocently plant it, regretting it years later when their once beautifully orchestrated garden bed has been taken over by this one plant.
Don’t let the beautiful foliage deceive you. It can spread by rhizome as pieces that fall off and easily root in the soil, and seeds that spread. It can also grow in almost any setting as well: sunny, shady, wet, or dry.
Best practice to get rid of it: a combination of herbicide, manual pulling, digging, and lots of sweat.
What to grow instead:
- Siberian bugloss (Brunnera macrophylla)
- lamb’s ear (Stachys byzantina)
- evolvulus (Evolvulus glomeratus)
Bigleaf Hydrandea (Hydrangea macrophylla)
Bigleaf Hydrangea (Hydrangea macrophylla) are a very popular choice for landscaping because their flowers vary in color, indirectly due to soil pH: shrubs grown in acidic soil (pH < 7) have blue flowers, while those in alkaline soils (pH > 7) have pink flowers.
However, when grown in St. Louis, this shrub often lets people down because it is not a reliable bloomer.
Bigleaf hydrangeas produce their flower buds on the previous season’s growth (flowers for 2023 were formed in 2022). Harsh winters and fluctuating temperatures in early spring often damage these buds. In the spring, the shrub will leaf out each year without issue. However, flowering is often a hit or miss. Some years, the blooms are fantastic. But more often than not, there’s little to no blooms.
What to plant instead:
- panicle hydrangea (Hydrangea panicle)
- smooth hydrangea (Hydrangea arborescens)
- oakleaf hydrangea (Hydrangea quercifolia)
Pin Oaks (Quercus palustris)
Thanks to their rapid growth rate, these native Missouri trees were planted in mass throughout the St. Louis region 50 or-so years ago. However, pin oaks need medium-wet moisture and acidic soils, things most St. Louis gardens and landscapes don’t have.
This is evident now as many stressed pin oaks in the area are becoming covered with tiny, galls formed by nonstinging wasps that are causing deterioration in the oaks. In the ideal conditions, pin oaks can easily fight off and survive these galls, but in St. Louis, these trees are under a lot of stress.
What to plant instead:
- red oak (Quercus rubra)
- chinkapin oak (Quercus muehlenbergii)
- nuttall oak (Quercus texana)
Blueberries (Vaccinium spp.)
Blueberries need acidic soil to perform well, and here in St. Louis our soils are typically more alkaline than they prefer.
Trying to lower the pH of soil in the ground is a daunting task, so blueberries perform best when planted in a raised bed or a container where growing conditions can be more carefully monitored.
They are also typically intolerant of clay-heavy soils as they need adequate moisture and well-draining, rich soil.
What to plant instead:
- serviceberry (Amelanchier arborea)
- pawpaw (Asimina triloba)
- rusty blackhaw viburnum (Viburnum rufidulum)
Lavender (Lavandula spp.)
Lavender is native to the Mediterranean region where there is sandy, very well draining soil, and mild temperatures. Comparitively, the fragrant perennial does not thrive in Missouri’s poor-draining or our cold winters and humid summers.
In the St. Louis area, it is best grown in a unglazed clay pot and moved to a sheltered location in the winter, or in a raised bed with amended soils and a rock mulch as opposed to an organic matter mulch.
What to grow instead:
- aromatic aster (Symphyotrichum oblongifolium)
- golden ragwort (Packera aurea)
- spice bush (Lindera benzoin)
Get answers to your specific gardening questions. You can talk with our garden staff and Master Gardener volunteers over the phone or through e-mail Monday–Friday, 9 a.m.–noon. Give them a call at 314-577-5143 or email at plantinformation@mobot.org. You can also talk with our gardeners in-person at the Kemper Center.
Jessika Eidson
Public Information Officer
Many thanks to the Kemper Center for Home Gardening Team and Daria Mckelvey, Supervisor of Home Gardening Information & Outreach for the expert information provided.
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