Thistles

We've been talking to Doug, a friend who works for the US Fish and Wildlife Service, specializing in prairies. He's been part of a ten year study on what affects thistle growth in prairies in the Midwest. Is it the time of the seeding of grasses and forbs? Is it the seed concentration as they are planted? Is it the type of prairie? Or is it related to something else that no-one has even thought of  yet?

We have at least five different types of soil on our farm and the thistles grow everywhere.One possibility is soil microbiome, the bacteria that live in the soil. Plants live in a reciprocal relationship with the bacteria in the soil. Our son-in-law, Gautam, is studying these soil microbiomes. They can vary from sample site to sample site. The microbiome a meter away from your sample can be as different as the microbiome of a site half way around the world.

So what does that tell us about thistles? I'm not sure but the fact that experts don't know is certainly reassuring to me. If it's necessary to do studies to figure out why and where thistles grow, then we're not the only farmers who can't keep our thistles under control. A month ago, I sprayed four pastures to kill thistles. Three weeks later, I resprayed to get the thistles I had missed the first time. Yesterday, Dave scythed the remaining thistles in those pastures. In three weeks, the tiny rosettes of golden spine tipped leaves metamorphosed into thigh high plants bristling with thorns and ready to burst into bloom.

Hopefully we have sprayed and cut them early enough that the seeds won't open and I can sleep easy in my bed, content that I haven't been the Typhoid Mary of thistle seeds this year. If not, I'll enjoy the beauty of the blossoms and try to do a better job next year.