My geese love weeds. They love any broad leaf plant, like lettuce, chard, radishes, anything in my veggie garden and all my flower plants..
They have weeded my orchard completely bare of weeds and also removed all leafs off the fruit trees as high as they can reach. They like the leafs off the rose bushes.
They do a great job in the orchard and I hand pull the weeds in the veggie garden and take them to the geese.
They like young grass and do a decent job with keeping grass short, as long as they are fenced out of any other plant you want to keep.
Mine have just started to pull leafs off my iris plants, so now I have to go and dig up all the iris in the orchard and move them to where the geese can't reach them.