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​What not to plant

There are very few things that make me angry. While most folks consider me laid back and of a relaxed nature, there are a few things that can make my blood boil. These can include social injustices, potholes on the interstate highway, and high on the list- thugs… specifically garden thugs. You may be asking “What is a garden thug?”.  I consider a garden thug a plant that just can’t behave in the garden. These are plants that will spread wildly or those that tend explode when the wind blows; generally plants that should be avoided. So, in honor of the coming of spring and for the love of the natural environment I will now give you my top 5 list of garden thugs.

kudzu - edited.jpg#5- Kudzu- The plant that ate the South
When many people hear the word “invasive”, kudzu is the plant that comes to mind. First planted by the state department as a means of controlling erosion, this plant has been considered public enemy number one on plant lists for a while. Why do I put it at number 5 and not number one?  First, most anyone with enough sense to walk around would think twice about planting kudzu. Second, I hope that there isn’t to garden center in this great land that would put this plant out for sale, unlike all of the other of the plants on this list.

#4- Chinese Tallow tree (aka “popcorn tree”)
Beloved for its fall color, this tree has been widely planted in landscapes across our great state for decades. Hailing from East Asia, this tree has quickly become a bane to southern ecosystems. The seeds are readily transported by birds and the wind and can seemingly grow wherever the seed lands. Not only is this tree a fast grower, but it also surrounds itself with a circle of toxicity. The sap of the plant is toxic, as are the leaves, making the plant successful in most any environment without the threat of predation. Options in lieu of the Chinese tallow tree include Ginkgo, crape myrtle and service berry.

#3 Japanese Wisteria
This is one of several wildly popular plants that have become incredibly invasive in the southeastern United States. Having been long favored for climbing on walls and over trellises in old fashion gardens, the plant quickly became a nuisance in natural areas. By forming a dense mat of vines, girdling and over-topping trees, this plant can easily become a dominate species if left unattended. While I can understand the potential interest in this plant with its large raceme of purple flowers and unusual seed pods, this is one that can get out of hand quickly. Confederate jasmine or the climbing rose known as ‘lady banks’ are two plants that could easy be used in place of this monster.

#2 Bradford Pear- A bad tree with beautiful blooms
I have a feeling that I am about to step on the toes of some people in this area. So, to protect myself, I understand; these are beautiful trees that bloom a pure white in the spring and have a great form and brilliant fall color. Now for the bad side- this tree is dangerous in more ways than one. First, the ‘Bradford’ was a selection from a tree known as the callery pear (Pyrus calleryana), a non edible pear native to China and Vietnam. Selected for its heavy bloom and upright nature, the ‘Bradford’ selection started out as a good garden citizen. It was widely popular throughout the United States (in a 2006 tree census of the city, the New York Parks Division counted 63,000 in New York City alone!) and continues to be sold at garden centers around the country.

Since its arrival, ‘Bradford’, which at one point was considered a sterile cultivar, has become widely invasive. Driving by abandoned city lots or along natural roadsides in the spring will show just how bad this plant really is. Aside from spreading to open lots and fence lines, this plant is indeed a danger in the landscape. Take a look around this spring after a thunderstorm and count how many of these trees are split down the middle. This weakness is due to that desirable upright nature which leads to what arborists refer to as “poor crotch angles”. These angles lead to included bark and cause pressure to build in the “v” of the branches. One good wind storm and CRACK!! There goes a major branch of the tree, crushing anything and everything beneath it. The second “danger” comes, not from the ‘Bradford’ selection, but rather with the reversion of the plant to the callery pear. The callery pear has some intense thorns- thorns that can puncture tractor tires and shoes or boots alike. Some options for replacement plants are fruiting pears, dogwoods, ornamental cherries and many others.

#1 Chinese Privet- botanical enemy number one
This plant is the one that could potentially be worse than what kudzu has become. Chinese privet, Ligustrum sinense, was once widely planted as privacy hedges and foundation plants. It has a thick, shrubby growth habit and can be considered “bulletproof” or almost invincible, to even the worst home gardener.

The aggressive nature of this plant, along with its ability to produce thousands of seeds per season, results in the formation of dense growths of privet in natural areas. These almost impenetrable colonies can choke out existing plants and prevent other native plants from growing. As mentioned, the plant blooms densely and produces loads of berries. These small, purple berries are loved by many species of birds, leading to numerous populations of privet along fence rows and wood lines. Adaptable to most any environment, privet hedge will inhabit both shady, wet conditions as well as dry, sunny locations. Aside from concentrated herbicides, privet has no enemies and can quickly take over open lots, woodlands and seemingly anywhere else.  Although this plant is visibly becoming our biggest threat to naturalized areas, many people continue to buy and plant this shrub. There are many alternatives to this exotic invasive including boxwoods, Japanese hollies, and dwarf yaupon.

So, that’s my list of top five garden thugs in the landscape. There are many others that could potentially be many others that fall into the thug category so when choosing a new plant try doing a little research, talk to your local garden center or call your local Extension office to ensure that this new plant will not become another landscape headache.

written by Hunter McBrayer of the Alabama Cooperative Extension System (ACES). He is an Urban Regional Extension Agent housed in the Marshall County Extension Office.


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