Skip to Content

Controlling Sicklepod Weed – How to Get Rid of Cassia Senna Obtusifolia

Sicklepod (Cassia Senna obtusifolia) is an annual legume that appears in the spring with yellow flowers and long pods.  It is invasive and can cause havoc in cotton, corn and soybean fields. Read on to get some tips for controlling sicklepod.

Sicklepod weed is a common problem for livestock producers

Photo credit: Wikimedia Commons

Sometimes plants appear in your garden by way of seeds in new mulch for spring, or by hitchhiking in via birds and other critters. For me, this was the case with some sicklepod plants.

This post may contain affiliate links. I earn a small commission, at no extra cost to you if you purchase through an affiliate link.

Facts about Sicklepod

Sicklepod is a semi-woody legume that is native to the American tropics. While the plant is classified as an annual, many consider it a weed because it is invasive and toxic.

  • Scientific Name: Cassia obstusifolia and Cassia Senna obtusifolia
  • Common Names:  Sicklepod, Java bean, Coffee Weed, Arsenic weed, Chinese Senna, American Sicklepod
  • Plant Classification:  annual

Cassia obstusifolia sicklepod

The plant was used by indigenous people as a medicine. 

The green leaves of the plant are fermented and this produces a high protein product called “kawal”.  This is often eaten in Sudan as a meat substitute.  

The plant is thought by some to produce a laxative effect and to be beneficial to the eyes.

I’m not entirely convinced that having a plant with a common name of arsenic weed would be a good idea!

Sicklepod is considered one of the most difficult weeds to control in soybean fields.  An infestation of it can reduce the yields in these fields by more than 60-70%.

Characteristics of Sicklepod

Cassia Senna obtusifolia has buttercup yellow flowers that grow on top of glossy green leaves. Soon after the flowers form, tendrils start developing, followed by what resembles a long green bean.

Senna Obtusifolia

Photo adapted from original at Wikimedia Commons

Hairless pale green leaves with twin petals will grown on a stalk that can quickly reach heights of up to 6 feet tall.

Sicklepod flowers and leaves

One interesting aspect of the plant is that the leaves close up at night, much like an oxalis plant, and then open again the next day.

The weed can easily be confused with coffee senna – cassia occidentalis. However, the leaves of sicklepod are blunt and coffee senna’s are pointed.

I first encountered sicklepod in my very first garden bed, when a plant appeared that I knew I had not planted. The leaves and tendrils resembled a sweet pea or baptisia australis, but was much faster growing.

I soon learned that this hitchhiker plant was not a desirable addition to my garden bed and needed to be removed before it decided to take over the surrounding space!

Toxicity of Sicklepod

In addition to sicklepod being invasive, it is also known to be toxic to livestock. It affects their liver, kidney and muscle functions. 

In addition, straw and hay that has been gathered from pastures that contain sicklepod cannot be used for livestock, since it will be contaminated with the crotalaria toxins in the plant.

Cattle and swine, as well as chickens and horses, are most commonly affected by sicklepod’s toxicity, but dogs and cats can be affected to a lesser degree.

(Many plants with otherwise appealing traits can be toxic to pets.  Check out my article on dieffenbachia to read about its toxicity.)

sicklepos can contaminate cattle feed

All parts of the plant from the stems and leaves, as well as the seeds and flowers, contain toxins. Poisoning occurs when the green plant, dried seed from harvested grain or contaminated hay are consumed. 

Controlling Sicklepod

The plant can be tough to get rid of.  It’s touch and will grow in even very poor soil.  The plant is also resistant to most plant diseases and quite drought tolerant.  Because of its toughness, controlling sicklepod can be somewhat difficult.

The best way to control sicklepod is to not let the weed get established. If you enter an infested area, clean your shoes, clothing and equipment so that it does not spread.

Be careful when buying mulch.  Find out, if you can, where it came from.  It is not unusual to have a whole host of new weeds (not just sicklepod) from contaminated mulch.

However, if you find it in your garden, you can remove it manually by pulling or digging it up.  Be aware that sicklepod has a very long tap root and the entire root must be removed, or it will grow back.Digging sicklepod

One also needs to be careful of mowing over sicklepod, since this usually results in seed spread, making the problem worse. If you are not careful, you’ll have a truly invasive plant on your hands. 

Liriope is another invasive plant that can take over a garden space. See my tips for controlling monkey grass here.

For larger infestations of sicklepod, eradicate with post-emergent herbicides. Herbicides with an active ingredient of 2,4-D works well in eradicating Sicklepod weeds in infected pastures.

For large farming concerns where the the plant has become a problem, this article will give some helpful tips for controlling it.

Have you run into this plant in your garden?  How did you control it?

Pin this post for controlling sicklepod for later.

Would you like a reminder of these tips for controlling Cassia Senna obtusifolia? Just pin this image to one of your gardening boards on Pinterest.controlling sicklepod

Admin note: This post for controlling sicklepod first appeared on the blog in January of 2013. I have updated the post with new images, much more information about the weed and tips for controlling it.

Share on Social Media

Richard OQuinn Jr

Monday 13th of May 2024

I have this damn weed in my fields every year right after i till the ground an the mud is fresh no mulch added just fertilizer i have several gardens that are 10 plus acres an this weed truly kills my production! Ive tried everything except using strong herbicide bc i grow all year long an i dont want the herbicide contaminating the next harvest! But from what I’ve read ill have no choice! Ive looked for an tried many things and these devils continue to grow and they just don’t die! Its crazy everything else will die but not this it will grow in droughts or anything! I guess ima try the strongest herbicide an ill have to shut down half my fields so the herbicide can do its thing then dialute over the next 6 months then if that works ill do the other half! Ill try that after this next harvest is done! I know ill lose product bc of this but if it works it will be worth it in the long run! Ill come back an give a update in a few months to let people know if that works! I live in southwest Mississippi so thats where i have this issue! Fingers crossed!

kathi coburn

Friday 3rd of November 2023

I have a question. Can it be burned so it doesn't grow back? I too have spent endless amount of time pulling them and I've been with these nasty plants for almost 3 years and it seems no matter what I do my pastor gets invaded more and more. The best time to pull these is when they're young but I'm wondering if they can be burnt out. Where they're dying now I would imagine it would be easier to pull them once they're dead. I'm at loss please reply to my personal email at k a t h i a n n e 051@gmail

Carol Speake

Friday 3rd of November 2023

I've never tried burning the plant so I have no idea how that would work.

Ann Kingsbury

Monday 1st of August 2022

I cleared 3 acres of pine trees to make a pasture for my goats. I bought plot mix that is for deer and several types of grasses.i dont know if the cassia seed was in some of those seed mixes but my field is completely taken over. I spend 2 to 3 hours daily in the Georgia 95 degree heat pulling this nasty plant before it can flower and spread through seeds. There are millions of them. Will it grow only from seed or will the roots last over the winter and grow ?

Carol Speake

Tuesday 2nd of August 2022

In my experience, as long as I get the tap root out, it doesn't grow back.


Wednesday 28th of August 2013

I think it's called Cassia.


Wednesday 28th of August 2013

HI Cathy, Thank you for the name. I had figured it out a while ago and added it to the article. I've been finding more of them this year. Apparently it is quite invasive.


Disclosure of Material Connection: Some of the links in the post above are "affiliate links." This means if you click on the link and purchase the item, I will receive a small commission from the sale, but the price is the same for you. I am disclosing this in accordance with the Federal Trade Commission's 16 CFR, Part 255: "Guides Concerning the Use of Endorsements and Testimonials in Advertising."