Weeds in Iris Beds

I have large iris beds that are overrun with weeds of all kinds. There are various trees coming up from birds and squirrels "planting" them, including black walnut, pecan, hickory, wild cherry, juniper, black locust, etc. There are vines including woodbine, poison ivy,, some briars, there is some grass, but mostly the vines and trees that are too big to pull out. It would be a massive undertaking to dig it all out and replant. I need some advise on how to get the weeds and unwanted trees etc. out of the beds and how to maintain them to keep them out. I also get a lot of vetch coming up and going to seed in the spring as well. I need help!

I had the sAme problem....I hired a man with a pic axe ...... out went everything....no more problems