Ironweed is a dreaded pasture weed with ornamental potential

My father-in-law would turn over in his grave. Ironweed is now a highly promoted ornamental perennial plant in many garden centers. He spent much of his life trying to get rid of it.

Ironweed (Vernonia sp.) is a tall perennial plant with bright purple flowers. It got its name because of the toughness of its stems. Some farmers might actually admit ironweed is a pretty plant if it didn’t take over pastures like it does.

The biggest problem with ironweed in pasture fields is that livestock won’t eat it. It’s not especially harmful to animals. It’s simply not palatable. Ironweed contains chemicals called lactones, but they must be consumed in large quantities to pose a problem.

Consequently, over time it spreads and that means ironweed plants take up more space in pastures. There’s less room for desired species that are constantly being grazed.

For dozens of decades farmers have fought this weed. They’ve clipped it. They’ve tried to grub it out. They’ve sprayed it. All methods have limited success.

There are broadleaf pesticides that will kill ironweed, but they also kill desirable pasture plants like clover and other legumes. Often reseeding of preferred forage crops is necessary.

Spot treating this weed can be effective and often eliminate the need for reseeding. However, it’s time consuming and often can’t be done while sitting on a tractor.

Ironweed spreads by seeds, so mowing plants before they go to seed can help. Plants also spread by underground stems called rhizomes. Ironweed also has an extensive fibrous root system. That makes it very tolerant of drought. In short, ironweed is one tough customer.

Ironweed is tolerant of just about every soil type. It even thrives in poorly drained and acidic soils. It grows in sun to partial shade as do most forage crops.

Unlike many problematic weedy plants, ironweed is not exotic. It’s a native plant. That’s one reason it’s gaining popularity as an ornamental. Plant breeders are developing more compact strains. Natives are all the rage right now.

I think this weed, I mean plant, has great potential for perennial gardens. I wouldn’t plant it near pastures, but it’s pretty and durable. Invasiveness is gradual, so gardeners should be able to keep it under control on a small scale. A small flower garden isn’t forty acres.

On the plus side, ironweed is a great attractor of pollinators. Bees and butterflies flock to it. Monarchs, painted ladies and tiger swallowtails are just a few of the butterflies you can see gracing the flowers.

Additionally, since livestock won’t touch it you might suspect deer and rabbits would follow suit. You’d be right. I’ve yet to see evidence of deer damage to ironweed, regardless of grazing pressure.

As is the case with many native herbs, ironweed has been used medicinally for centuries. Root concoctions have been used to regulate menstrual blood flow.

Herbalists have also prescribed ironweed to treat stomach pain and general bleeding. Root infusions supposedly help firm up loose teeth. Few side-effects have been reported. Allergic reactions causing skin irritations are possible though.

Ornamental ironweed in flower

Ted Manzer teaches agriculture at Northeastern High School (

About tedmanzer

I grew up in Old Town Maine and got a B.S. at the University of Maine in Plant Sciences/ minor in Botany. From there I moved to West Virginia and earned a M.S. in Agronomy at WVU. I also met my wife there. She grew up in rural WV as the daughter of tenant farmers who raised cattle and hogs. Their lifestyle at times was one of subsistence and I learned a lot from them. I've always been a foraging buff, but combining my formal botanical knowledge with their practical 'Foxfire-type' background opened up my eyes a little more. I recently retired from teaching high school agriculture after 25 years teaching with my wife. Until recently I wrote a weekly nature/foraging column for the local paper ( I also have written several Christian nature/adventure novels that can be purchased on Amazon in Kindle format. One is a five book family saga I call the 'Forgotten Virtues' series. In the first book, Never Alone (presently out of print), a young boy comes of age after his father dies in a plane crash, and he has to make it alone. The second book, Strange Courage, takes Carl from his High School graduation to his recovery from a nasty divorce. The third book, Second Chances, takes Carl from his ex-wife's death and the custody of his son to his heroic death at age 59. The fourth book, Promises Kept, depicts how his grandchildren react and adjust to his death (this one is not yet published). In the final book, Grandfather's Way, his youngest and most timid granddaughter emerges from the shadow of her overachieving family and accomplishes more in four months than most do in a lifetime. I use many foraging references with a lot of the plants I profile in these articles in those books. I also wrote a romance novel titled Virginia. It is available on Amazon and is a different type of romance from a man's perspective.
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