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OSU Extension

College of Food, Agricultural, and Environmental Sciences

June 9, 2020 - 8:00am --

Cressleaf Groundsel is a toxic plant that has become much more common in both agronomic row crop as well as hay fields over the past several years.  The concern is for those forage fields that have recently been baled or chopped for ensiling and that contained significant patches of this weed in the field or uniformly scattered through the field to compose 5% or greater of total forage dry matter. That forage poses some significant toxicity risks to livestock consuming that forage.  If Cressleaf Groundsel is a problem in your forage fields, make a note of those fields and mark your calendar for a fall herbicide application for control. Recently Jason Hartschuh, Extension Educator in Crawford County and Ted Wiseman, Extension Educator in Perry County wrote about the toxicity of Cressleaf Groundsel. Here is what they have to say. 

“Cressleaf Groundsel is toxic to both cattle and horses. Cattle are 30-40 times more susceptible to poisoning than sheep or goats. Calves and younger cattle are more susceptible than older cattle, but it can be fatal at high enough doses to all age groups. Pyrrolizidine alkaloids are the principle toxin in these plants. It is known to cause liver disease in cattle, producing symptoms such as listlessness, decreased appetite, depression, anorexia, diarrhea, and photosensitization in extreme cases. It also appears that this species has been responsible for abortions in cattle, making control of butterweed a necessity. Cattle that consumed 4 to 8% of their body weight in the green plant over a few days developed acute liver necrosis and died within 1 to 2 days. Cattle that ingested 0.15% of their body weight (fresh weight) of a species in the same genus as butterweed for a minimum of 20 days resulted in 100% mortality. This comparative ratio equates to a 20-day cumulative dose of 2% of an animal’s body weight of dry plants (Knight and Walter 2001). Most beef cattle will consume 2-2.5% of their body weight in dry matter per day. Since these toxins are cumulative when hay is over 5% Cressleaf Groundsel dry matter weight, enough can be consumed within 20 days to cause mortality.

While toxicity decreases in some plants as they dry, that is not the case with Cressleaf Groundsel. These toxins are not decreased if the plants are dried and baled. Ensiling will decrease the concentration of toxin but not eliminate them. Producers with high concentrations of Cressleaf Groundsel may be forced to bale first cutting and throw it away so that livestock are not poisoned. Areas of sparse concentration may be baled and fed cautiously, ideally alongside hay that is free from poisonous weeds. Cattle may sort the weeds out. A new bale should be fed before the only thing left in the feeder is weeds. In grazing situations, cattle will usually not eat poisonous plants when they have access to other quality forages. Be cautious anytime drought conditions decrease forage stands.

Cressleaf groundsel reproduces only from seeds and emerges as a rosette in the fall, then bolts, flowers, and goes to seed in the spring.  Bolting stems are hairless, hollow, grooved, and can reach heights of three feet with inflorescences that have six to twelve yellow ray flowers.  The flowers are like other species in the Aster family, with ray (outside) and disk (center) petals.  For more information on identifying Cressleaf Groundsel go to

Cressleaf groundsel normally does not regrow after the first cutting of hay; however, our goal should be to prevent it from becoming established in the field. Take note of fields with Cressleaf Groundsel in them or nearby for increased scouting and control measures next year.  Effective chemical control is when the plants are still in the rosette growth stage in late fall or early spring.  Herbicides such as 2,4-D provide good control when applied at the correct growth stage.  Products that can be used to control this weed and others can be found in the 2020 Weed Control Guide for Ohio, Indiana, and Illinois.  One caution using these broadleaf herbicides is that they also damage legumes such as alfalfa and clovers in pastures and hayfields.”

USDA Provides More Clarification on CFAP

This past week, USDA provided some helpful clarification for agricultural producers making application to the Coronavirus Food Assistance Program (CFAP).  There had been some questions and uncertainty regarding eligibility of various types of marketing contracts for the non-specialty crops such as corn and soybeans. See this chart on-line, for definitions of marketing contracts and their eligibility.  Likewise, questions had been raised on definitions of cattle for inclusion in CFAP.  There is now a very comprehensive chart at  with commonly used cattle terms, definitions and applicability to CFAP.

Application for CFAP is made through the Farm Service Agency office through August 28.


Rory Lewandowski is an OSU Extension Agriculture & Natural Resources Educator and may be reached at 330-264-8722.

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