Hi , I did multi layers of cardboard and thick mulch.
Once the cardboard breaks down the cooch thrives.
Sits dormant waiting to hit the sun.
One year max in Victoria Australia and it's running rampant again.
Only way is to dig it out..I'm doing it now.
Nightmare job actually easier on areas I didn't mulch so much as it tends to grow along the top of the clay.
But in the thick mulched areas it's a bohemeth running all over the place thick white roots like spaghetti.
I sheet mulch every 3 years.
No grass property just natives and mulch.
Prob ok if a food forest but in my vege patch it just keeps popping up.
Dig it up and even then any bits left behind will take off.
Good luck ..hard yards = more fun.
