Thanks for the replies. I like the idea of a scythe, but they are forming a "bulb", sort of purple at the top, should this be of concern if I were to use a scythe? Around this time last year I went "ninja" on the whole patch with two machetes. It was a lot of fun and exercise, but they grew back. So in chopping them, am I "helping" them to spread, or do they just decompose? I figure since the thistle harvest this year appears to have grown by almost 2x in this particular area, that I either helped them to spread or they somehow spread/grew from the root system.
On another note, if I were to chop them and use them in an 18 day compost, would I have contamination in the compost of these weeds? I just watched "Permaculture Soils" and saw that weeds could be used and I'm not too sure of this (though trust the info coming from Lawton, just don't understand how the weeds will not contaminate).