
First of all thistle isn't necessarily just a weed. It's a good flower for the bees to feed from in the summer and a great source of nourishment for the birds as well. However if you like to run barefoot through your lawn - or have children who do - stepping on a thistle can be a nasty surprise! Imagine playing a game of backyard football and getting tackled on top of one of these spiky menaces! OUCH!
You don't need chemicals to remove thistle. In fact probably the most effective way to get rid of it is to dig it out. It has a long tap root and you need to make sure that you get all of it our or else you risk a repeat performance. Additionally (although I don't do this for thistle) you could pour boiling water on the hole area where you just removed the thistle. That should kill off the remaining roots. No chemicals are necessary!
If you have a very large area to clear of thistle regular mowing may do the trick over the long haul. Mowing the thistle will cause it to use its stored energy to regrow which then gets cut back again. Eventually it will be unable to sustain its growth and won't be able to produce seed. This strategy works for many weeds but requires the repeated removal of the plant which can be a tedious process.
Bull thistle is a biennial plant and will produce leaves the first year and will flower in the second year.
So have you stepped on any thistle lately?