Thistle isn’t a problem for me, I wonder why it is for you? They get pulled out one at a time and get eaten. Now black sunflower seed is messy for me so I use the cracked sunflower in the cardinal feeders and the finches have started feeding there after they eat enough thistle. And put some raisins in your suet basket, the mockingbirds LOVE them. In fact I don’t even put suet in my suet basket, just raisins. I buy the suet pellets and mix them with the cardinal/woodpecker food.
The birds crap thistle seeds and the thistles grow all over my yard and the limited landscaping I DO have....and Im not all that into weeding ;-)
I also inclue Safflower seeds for hte cardkinals,,, and the finches seem to eat those too