Hi Ninasada,
Improve your soil and fertilize to deter them. They are weeds and don't care for fertile soil. I bet Rita washed away your good topsoil and exposed the seeds. I've also read that keeping the lawn mowed short will cut off the plant before it blooms and creates those nasty stickers.

HTH
Pam

And THAT's the TRUTH!

Run get some 21-0-0, or 13-13-13. Either will do. Sprinkle out where you have those stickers and they will die quick.

Janie

Pull them up and seal the plants in bio-hazard bags. Just kidding, sort of. LOL

They are in our alley and every year, I must pull them in a direct line from the back gate to the back door.

There is something very satisfing about pulling them up, sealing them in a plastic bag and sending them to the dumpster.

We had tons of stickers in the yard growing up and the only way to get rid of them was to pull them up one by one. Make sure you bag them up securely and throw them away. Do not compost them or burn them, you could still have seeds make it through the process. If you try to use a chemical, you may kill the plant but will not kill all the seeds left behind in the soil. It make take a few seasons, but if you are diligent you will get rid of them. Start asap so they don't multiply!

I read this idea somewhere and thought it was creative- to pick up the stickers drag an old blanket or towel over the area to collect the stickers/seeds. Discard. Treat plants with your choice of plantacide.