These farms are ideal gleaning sites because they are easier to access than traditional farms and usually have harvesting equipment (like ladders and bags) available for your group.
Set up U-Pick gleans using Food For Others' best practices.
Gleaning a u-pick farm will increase the farms publicity while allowing the farm to give back to the community.
The Yakima Valley Produce Harvest has had success with u-pick orchards; we have used these sites to diversify both the type of growers we work with and the type of produce we harvest.