Be Your Own Plant Detective: Spot Invasives

By Lisa Nadler and Martha Keehner Engelke, NC State Extension Master GardenerSM volunteers of Durham County

Sometimes a plant becomes a rapid spreader working its way into places where you would rather it not go. Coral honeysuckle (Lonicera sempervirens) is an example of this. It is a vigorous twining vine that is native to the eastern United States. It can grow 10-20 feet high in a season. It spreads aggressively. But, because it is native to our ecosystem, it doesn’t displace other native plants in the area. It is not invasive. In contrast, its “cousin” Japanese or Chinese honeysuckle (Lonicera japonica), a native of Asia, is capable of growing over plants and smothering them. It can displace native species by outcompeting them for light, space, water and nutrients.

The term invasive applies only to non-native plants; invasive implies a negative effect on native plants and animals. On the other hand, native plants that establish quickly in your garden and spread readily are more appropriately termed “aggressive.”  Aggressive native plants generally are species adapted to recently disturbed sites where they establish and spread quickly but give way to other native plants within a few years”.1

So, how do you tell the difference?

Two of the pictures above are Lonicera sempervirens (native) and two are Lonicera japonica (invasive). Can you tell the difference? Answers are at the end of the post. (Image credit: Top left: Debbie Roos; Top Right: Lucy Bradley, CC-BY 4.0; Bottom left: Hope Duckworth CC- BY 4.0; Bottom right: Chris Kreussing CC-BY-NC-ND 2.0)

Lisa Nadler’s adventure to distinguish a native plant from an invasive plant is enlightening. It is an excellent illustration of how two plants that seem similar and are in the same family are vastly different in the impact they will have on your garden.

Plant Detective: Lisa Nadler

On a recent visit to Cocoa Cinnamon Container Garden2, Lisa Nadler made a discovery. Invasive Chinese or Sericea Lespedeza (Lespedeza cuneata) was in one of the painted pots. Lespedeza is in the Fabaceae, or bean family.

The picture on the left shows Lespedeza cuneata growing in a pot at Cocoa Cinnamon. In the photo on the right Deb Pilkington holds the plant after it is removed illustrating its long tap root (Image credit: Lisa Nadler)

So, what is Lespedeza and how did they know it is bad? There are both native and invasive Lespedeza plants and they can look similar. So, you need to know what to look for to know which ones to yank and which ones to leave.

Sericea lespedeza (Lespedeza cuneata) is a warm-season, perennial legume with many erect, leafy branches. It also goes by the name of Chinese Bush Clover. It was introduced from Asia in 1896 for erosion control, livestock forage and wildlife cover.  But, it has no natural diseases or insects to manage it here and it is now listed as a Rank 1-Severe Threat in NC.

According to the NC Plant Toolbox, it may be allelopathic, producing substances that chemically inhibit the growth of other plants. It forms extensive monocultures and develops an extensive seed bank in the soil, ensuring its long residence at a site. Its high tannin content makes it unpalatable to livestock and most native wildlife. So, not a very good addition for wildlife feed. It can grow up to 6 feet tall and once you know what it looks like, you’ll start seeing it everywhere, especially on road sides.

But how can you tell it from the native Bush clover species, Lespedeza virginica and Lespedeza capitata? Here are some clues.

Bloom Color (which wasn’t helpful in this case because it wasn’t in bloom.)

Lespedeza cuneata has white blooms with a touch of purple. The native Lespedeza virginica has purple flowers. But… (isn’t there always a but…) the other common native, Lespedeza capitata, has white flowers but with a redder touch.

The picture on the left is Lespedeza cuneata which is invasive. In the middle is Lespedeza virginica, a native and on the right is Lespedeza capitata, another native. (Image credit: Anita 363 CC-BY-NC 2.0; CC-BY-SA-2.0; CC-BY-SA 2.0)

Leaves

Okay, so now look at the leaves. The Lespedeza cuneata (the bad guy) has leaves that are more rounded at the end with a single tooth. Also, the veins are straight and easily visible. The leaves of the Lespedeza virginica and Lespedeza capitata (the good guys) are pointier at the end, usually have a less prominent tooth and the veins are curvier (I’m sure there is a specific botanical name for that…).

Left to right: Lespedeza cuneata; Lespedeza virginica; Lespedeza capitata (Image credit: Hamilton Native Outpost; Bonnie Semmling CC-BY-4.0; Missouri plants. com).

There are other plant families that include both native and invasive species so it is important to always be on the lookout. The Poaceae family includes invasive and native grasses. The aquatic common reed (Phragmites australis), is native to Europe but very invasive in NC. It spreads rapidly and forms dense stands. Within the Rosaceae family we find native plants but also the highly invasive Multiflora Rose (Rosa multiflora). Plants in the Oleaceae Family are popular ornamentals and there are some natives but invasive species like Autumn Olive (Elaeagnus umbellata) and Russian Olive (Elaeagnus angustifolia) should not be planted. Autumn olive was introduced for wildlife habitat and ornamental purposes but has become invasive. Finally, we have the Fabaceae family. While Wisteria frutescens is a native, Chinese Wisteria (Wisteria sinensis) and Japanese Wisteria (Wisteria floribunda) are invasive vines in North Carolina. 

So be on the lookout and be your own plant detective!

Answers to quiz: The picture on the upper left and lower right are native (Lonicera sempervirens) the other two are Invasive (Lonicera japonica).

Note 1: This article by Christoper Moorman and Dr. Lucy Bradley, summarizes the differences between aggressive and invasive plants. https://gardening.ces.ncsu.edu/how-to-create-wildlife-friendly-landscapes/why-landscapes-for-wildlife/invasive-species/

Note 2: Cocoa Cinnamon is a demonstration garden located at 420 West Geer Street, Durham, NC 2770. The Durham EMGs provide oversight and it has been an amazing source of information on best practices for growing plants in containers. Here are a few examples of previous posts inspired by the Cocoa Cinnamon project:

Winter pruning of “Little Miss Figgy”: https://wp.me/p2nIr1-5Xr

“Little Miss Figgy in the City” https://wp.me/p2nIr1-50Z

Give a thought to the pot: https://wp.me/p2nIr1-4sZ

Pot Luck: Adventures in Urban Container Gardening: https://wp.me/p2nIr1-2jZ

Pot Luck: A Wildlife Ecosystem in the Middle of a City? : https://wp.me/p2nIr1-2tn

Another series on invasive plants and alternatives by Jeanne Arnts, was recently published on the blog:

From Beloved to Invasive: How does it happen? https://wp.me/p2nIr1-5l3

Replacing Invasive Plants: Suggestions for Beneficial Alternatives https://wp.me/p2nIr1-5CJ

Additional Reading and Resources

For more information on plant diversity check out this article from the NC Botanical Gardens. https://ncbg.unc.edu/2025/03/06/what-are-the-most-diverse-plant-families-and-why-part-one-the-asters

The NC Native Plant Society has good information on identifying native vs. invasive plants. https://ncwildflower.org/invasive-exotic-species-list/

How do invasive plants affect our forests? Here is the answer: ttps://content.ces.ncsu.edu/invasive-plants-and-your-forests

Article Short Link: https://wp.me/p2nIr1-68z

Mustard: It’s Not Just for Hotdogs

By Melinda Heigel, NC State Extension Master GardenerSM volunteer of Durham County

(Left) The big, bold leaves of ‘Red Giant mustard take center stage in this large container providing texture, height, volume, and intense color. This mustard was fast growing, survived cold temperatures with minimal protection. It was also slow to bolt when the weather got warm in the spring. (Middle and right) The ‘Miz America’ mizuna-mustard hybrid was equally stunning in a built-in planter box and potted alongside pansies, violas, and a lemon cypress, (Hesperocyparis macrocarpa ‘Goldcrest’ ). While these head turners are edible, I planted them for their color and form. (Image credit: Melinda Heigel)1

Wait? I thought this was a blog about gardening, not cooking! Well, the mustard I am referring to isn’t the zippy condiment we all know but is the plant I discovered is a star in fall containers. I’ve written in the past about the herb bloody dock, also known as sorrel, and what a bullet-proof companion it is for pansies, violas, snapdragons, ornamental kale, cabbage, and other autumn-to-spring plants. Last year I tried adding mustard to my potted arrangements and was thrilled with the results.

A Question of Hardiness

Along with broccoli, collards, and kale, mustard is a cole crop that performs best in consistently cool temperatures when grown in the vegetable garden. But over the last couple of years I’ve started seeing different mustard plants at the local nurseries more and more alongside the annual cold-weather ornamentals. The mustard plants offered some really interesting leafy forms for planting in pots. I was dubious, though, about their hardiness over the winter, unprotected in containers, but what is gardening without experimentation? With the exception of a couple nights with temps in the teens in the dead of winter, I did not cover any mustard plants. To my surprise, they performed just as well as their cool-weather container companions.

(Left to right) Mustard plants already making a debut at the local nursery this month alongside fall’s usual suspects. In late spring of 2024, my ‘Miz America’ mustard plants produced bright yellow flowers when they bolted. The plants really earned their keep–providing interesting leaves for months followed by these showy late-spring blooms. And did I mention spring pollinators were drawn to their nectar and pollen? (Image credit: Melinda Heigel)

If the spring weather warmed up too quickly, as it is known to do in central NC, I also wondered whether these cool-temp lovers would bolt (flower) and fade too quickly given their prominent placements. Most of the containers were in the hottest place around our house–on a dark-colored deck that receives full sun. Happily, the mustard tolerated a good number of hot days in late April and early May before bolting. Even after flowering, they were still going strong when I removed them to make way for summer plants. While I may have just the right conditions in my landscape for these results, I can’t chalk this success up to anything remarkable. Mustard plants are easy to grow. And I’ve come to find out, one of the types I planted is actually bred to be bolt resistant, ensuring longevity.

Mustard Varieties for Annual Container Gardening

Red Giant Mustard (Brassica juncea ‘Red Giant’)

I found this to be a striking specimen. In my big container, it quickly grew to be over 3 feet tall, with gracefully arching leaves that reminded me of a classical acanthus—yes, you really can wax poetic about mustard. If grown in optimum conditions, this plant has been reported to grow as large as 4 feet. Though I have not experienced this, don’t underestimate its vigor. When planning your mixed pot, give it plenty of room. ‘Big Giant’ mustard leaves start off green but mature into a deep maroon with contrasting green stems, midribs, and leaf veins. This plant is specifically bred to be both cold-and-bolt tolerant. Frost intensifies the color. It grows best in full sun with well-drained soil. It paired nicely with the flowering cushion spurge ‘Ascot Rainbow’ (Euphorbia x martinii ‘Ascot Rainbow’) as a backdrop.

In terms of its characteristics as an edible, this mustard has a bold taste like wasabi or horseradish and can be pickled, eaten cooked (mature leaves), and eaten raw (young leaves). Hot weather sharpens the flavor, especially in the older leaves of the plant.

Image credit: Melinda Heigel

Miz America Hybrid (Brassica juncea ‘Miz America’)

At once striking and delicate, the deeply lobed and serrated leaves of this mustard are a showy deep burgundy with vibrant hot-pink midribs and venation. Like ‘Red Giant,’ it is a fast grower and prefers full sun. It serves as an excellent filler in containers, given its upright and compact habit.

From a culinary perspective, ‘Miz America’ has a mild peppery flavor. It’s a hybrid plant that comes from crossing two distinct mustard varieties. One of the parents, mizuna, is a mild green mustard, which gives ‘Miz America’ its beautiful serrated edges and mild flavor. You can enjoy the leaves of all mustards in a salad by picking them young—under 6 inches. If picked at a more mature size, they can be added to a dish to impart a hint of sweetness with a mustard tang. Consider adding them to a bowl of hot, creamy soup such as butternut squash or tomato. Not only does it give you additional nutritional value without adding additional calories, but it adds a nice crunch and a bit of zing.

I’ve yet to replant my containers and built-in planter box this fall, but you’d better bet that mustard plants will be making a repeat performance in 2024. I’ve already seen ‘Red Giant’ in the nurseries, but I am also on the hunt for some other intriguing mustards to test out—namely ‘Brazen Brass’ and ‘Dragon Tongue.’ If you want something unusual, showy, and even tasty in your fall plantings, remember to go heavy on the mustard.

Notes

1–Want a closer look at a photo? Simply double click on the image for a better view.

2–According to Missouri Botanical Garden, Brassica juncea, known by its common names Chinese mustard or brown mustard, is listed as a noxious weed in some states including Michigan, Florida, and Alaska and considered invasive. Cultivars discussed here are bred to be used as annual edibles or ornamentals in gardens.

Resources and Additional Information

Article Short Link: https://wp.me/p2nIr1-54k