Milkweed and Hemp Dogbane - Who’s Who?

Jul 09, 2021

By Christine Gelley

Both milkweed and hemp dogbane have become more apparent in the area over the past week. These two plants are related but have some distinct differences that can help landowners identify them and implement control measures when needed.

Similarities between the two include having creeping roots; leaves that appear on opposite sides of the stem; and they produce a milky sap. Differences include that young milkweed leaves have fine hairs and hemp dogbane are nearly hairless; milkweed stems are generally thick and green, but hemp dogbane stems are usually red to purple and thinner in comparison; hemp dogbane frequently branches in the top canopy, while milkweed will typically not branch unless mowed; and seed pod shape is distinctly different after flowering with milkweed producing an upright tear drop shaped pod and hemp dogbane producing a long bean-like pod that hangs from the plant.

While the usefulness of milkweed in the landscape is often justified for monarch butterfly populations, hemp dogbane has fewer redeeming qualities. Historically hemp dogbane has been used by Native Americans to make rope, clothing, and baskets. Both have the capability of spreading rapidly by their creeping roots and seed production. Both are best controlled in agricultural settings by a combination of strategic mowing and systemic herbicide application.

Both milkweed and hemp dogbane are considered poisonous to livestock. Toxicities can occur from fresh or dried leaves, stems, and roots. While death from poisoning is rare, reduced production efficiency is common if consumed. Symptoms range from mild to severe and include vomiting, diarrhea, coordination loss, tremors, heart problems, respiratory distress, and death.

While eliminating milkweed and hemp dogbane from all ecosystems would be unwise, treatment of some kind is advised in situations where livestock are consuming forage from areas with high populations.

According to the 2021 Ohio, Indiana, and Illinois Weed Control Guide, both milkweed and hemp dogbane are significant agronomic weeds in no-till systems. Various postemergence herbicides can be effective on milkweed and hemp dogbane if the plants are less than eight inches tall. For the best control of the creeping root system, applications of translocated herbicides should be applied when the plants are in the bud to flower stage. Attaining complete control after one herbicide application is unlikely. The most appropriate time to treat and product to use depends on the situation. Commonly used herbicides for suppression or control include glyphosate, 2,4-D, dicamba, and triclopyr products. Always follow the directions printed on the herbicide label for application rates, methods, and concerns.

Source : osu.edu

Video: Why Your Food Future Could be Trapped in a Seed Morgue

In a world of PowerPoint overload, Rex Bernardo stands out. No bullet points. No charts. No jargon. Just stories and photographs. At this year’s National Association for Plant Breeding conference on the Big Island of Hawaii, he stood before a room of peers — all experts in the science of seeds — and did something radical: he showed them images. He told them stories. And he asked them to remember not what they saw, but how they felt.

Bernardo, recipient of the 2025 Lifetime Achievement Award, has spent his career searching for the genetic treasures tucked inside what plant breeders call exotic germplasm — ancient, often wild genetic lines that hold secrets to resilience, taste, and traits we've forgotten to value.

But Bernardo didn’t always think this way.

“I worked in private industry for nearly a decade,” he recalls. “I remember one breeder saying, ‘We’re making new hybrids, but they’re basically the same genetics.’ That stuck with me. Where is the new diversity going to come from?”

For Bernardo, part of the answer lies in the world’s gene banks — vast vaults of seed samples collected from every corner of the globe. Yet, he says, many of these vaults have quietly become “seed morgues.” “Something goes in, but it never comes out,” he explains. “We need to start treating these collections like living investments, not museums of dead potential.”

That potential — and the barriers to unlocking it — are deeply personal for Bernardo. He’s wrestled with international policies that prevent access to valuable lines (like North Korean corn) and with the slow, painstaking science of transferring useful traits from wild relatives into elite lines that farmers can actually grow. Sometimes it works. Sometimes it doesn’t. But he’s convinced that success starts not in the lab, but in the way we communicate.

“The fact sheet model isn’t cutting it anymore,” he says. “We hand out a paper about a new variety and think that’s enough. But stories? Plants you can see and touch? That’s what stays with people.”

Bernardo practices what he preaches. At the University of Minnesota, he helped launch a student-led breeding program that’s working to adapt leafy African vegetables for the Twin Cities’ African diaspora. The goal? Culturally relevant crops that mature in Minnesota’s shorter growing season — and can be regrown year after year.

“That’s real impact,” he says. “Helping people grow food that’s meaningful to them, not just what's commercially viable.”

He’s also brewed plant breeding into something more relatable — literally. Coffee and beer have become unexpected tools in his mission to make science accessible. His undergraduate course on coffee, for instance, connects the dots between genetics, geography, and culture. “Everyone drinks coffee,” he says. “It’s a conversation starter. It’s a gateway into plant science.”