I’ve never minded a bit of mess in the outdoors… certainly easier on me, and now I’m discovering birds thoroughly enjoy these areas. Leave an old fence post standing and see who finds it! I’ve watched Northern Flickers playing on them, seen sparrows use them as viewing posts, and observed smaller birds using the old wire to reach tall grass seeds (left and below). Fallen tree branches at the edge of the lawn not only add a possible bug (food) source, they are also good places for a quick cover while darting back and forth to feed.
My favorite though was the small nest I found tucked at the base of "past-their-prime" lupine stalks -- the nest had three recently-hatched White-crowned Sparrows (closed-eyed and open mouthed). It was nearly invisible surrounded by tall grasses.
Beneath the fence (above with the sparrow) is an old log; recently I watched six small birds (a variety of finch, sparrows and chickadees), all sharing the space while feeding.
So instead of cleaning out all those overgrown stalks and posts, sit back with a cup of coffee and watch what may be using them!