Canadian farmer shares his two-prong
attack on Canada thistle

Tools, technique, cropping sequence optimize “management” of weed that thrives on slicing and dicing of cultivation with sweeps.

By Steven Snider

editor's NOTE:

When we read about Steven Snider’s approach to thistle control in the June 2006 edition of Acres USA, we wanted to get his wisdom to follow-up on our July “Ask Jeff” thistle question from a reader in Ontario. If you’ve found a successful weed-fighting combination, let us know by clicking on “Share Your Story” on the upper right corner of this page.

--NF

Posted August 10, 2006: Canada thistle is a frustrating weed. First off, understand that you will never eliminate it forever. As soon as it is gone, seed drifts in from somewhere else and takes hold. My objective is to manage populations to acceptable levels, i.e. patches small enough to be mowed out of the crops. On the tillage side, I use a spike-tooth cultivator followed by a rodweeder to pull out the thistle plants. The spikes loosen the root, and the rod pulls as much root as the strength of the root allows. I regularly pull out 6 to 8 inches of thistle root, but the length will vary by soil type, moisture and weed stage.

If you have thistle, get rid of all sweeps on your cultivators. A sweep only cuts at the depth of tillage and allows for more competitive re-emergence.

I agree with Jeff Moyer on the use of hay and rye, but I will qualify the rye idea: You must have enough soil health to produce at least a 60-bushel-per-acre crop—any less, and you lose a lot of competitive advantage against the weeds. I try to build the soil with a plowdown crop first, seeded late spring to allow a flush of thistle. Incorporate in late July, and seed to fall rye in the first week in September after another spike/rod pass. Don't underestimate the value of fall tillage on thistle either.

We commonly disc our rye stubble and what thistle may be left is "pulled" out by the disk. The rod is useless in the heavy straw because it will not clear the residue. Hay does eliminate thistle, and it provides income at the same time.

The photo shows that Kongskilde has a specialized shank unlike any other, one with a hook specifically designed to pull and kill quackgrass. As a matter of fact, the original spikes for it had a pull-out sheet on how to cultivate to kill quack.

One further detail on my cultivator set-up: Notice the type of spring mount used. It is two band springs, eliminating any bushings. The neat part is that it allows for movement side to side as well as front and back. This gives a whole new meaning to term “vibra-shank,” the critical action in shaking out quack roots.