What to do with half-full peanut feeder?

Apologies for what sounds like a duplicate question but the situation is a bit odd. I have a standard mesh feeder for whole peanuts and it attracts all the usual birds including greater spotted woodpeckers and parakeets however, once the feeder level reaches about half the woodpeckers and parakeets seem to stop eating the nuts. I am assuming it has to do with not being able to position themselves properly to peck at them. I would like to refill the feeder but what do I do with the leftovers which have been out for almost a month? Should I just leave them on the ground for the squirrel to take? Seems like an awful waste having to chuck out 50% of the peanuts. Or maybe I'm supposed to throw them out after 4 weeks anyway? I'm not keen on kibbled peanuts as the starlings will mob it.