I just finished a near exhaustive multi-room search for one of my weed books and finally located it in a bookcase (last place I looked). You folks that are highly organized and well-kept have my highest respect. Alan Newport told me a while back that he has given up hope for R.P. Cooke being organized. Truth is that Alan is normally quite accurate.
I was looking for information on common cocklebur, which is found from the Alabama, Mississippi, and Texas Gulf Coast all the way into southern Canada and above. From the east coast to west most farmers and ranchers know and recognize what you’re talking about when you mention cockleburs.
The two-leaf stage of early growth is very toxic to pigs. The seeds can also poison cattle, especially calves. The burs are commonly a cause of preputial lacerations in bulls in the fall of the year. In the South, a milk cow’s switch full of cockleburs commonly caused quite a severe pain in young men and women when they were juicing ol' “Bossy” on a cold, winter morning. Removing the hair from the switch was a common way to avoid this.
I have purchased cattle in the fall from traders that had enough burrs and seeds to sow a bunch of acres. Each burr contains multiple seeds and they are capable of germination for many years. They can come up in the spring or wait for moisture all summer and into early October. A fall seedling can make burrs in just a few days post emergence. Three crops of cockleburs in one year is common on our area.
I have never met a cattleman that did not consider cocklebur to be a bitch wolf. Ground that has ever hosted crops, hogs or congregated cattle for any length of time normally has cockleburs, and if there is any bare ground it can easily host thousands of plants per acre. They love ground with good moisture and some fertility.
If sprayed on them early, 2, 4-D is quite effective, but on high-moisture years a second and often third crop will appear. You can easily take out a bunch of good legumes and other broadleaf plants while fighting cockleburs. Most methods of control have merit on given years if the strategy and timing are near perfect. But remember, they will be back. There is almost no such thing as a free lunch!
I once bought an acreage that several decades earlier had belonged to a pig trader. I didn’t notice a cocklebur problem that fall, since it had been sprayed and bush hogged a few weeks earlier. I wish I had paid closer attention, even though it probably would not have changed a thing.
For most of the past 15 years we have had enough cockleburs to start a war. I’ve pulled up and spot sprayed enough cockleburs to load more than a few pot trailers.
This past year we have seen near zero cockleburs. Why would that be the case as we have experienced above-average moisture every month?
I looked at the daybook to have a go at figuring the answer.
The cattle left the acreage on March 30 after several weeks of high-density grazing of new growth and left-over forbs from early September. Lots of grass and legumes and forbs came in April, May and June. More forbs followed in a big way in July, August and September.
We unloaded a mob of steers on September 14. Some of ya’ll have never seen a jungle like the one we had. Seven weeks later we had averaged 140 cow days per acre (1 cow = 1,000 pounds) and there is not a cocklebur in the switches or on my britches.
I’d sure guess they will be back in the future but you can bet that I will attempt to repeat the 2017 treatment of complete growing season plant recovery every three or four years in the future. It sure appeared to work this time.