Re: Sun flowers / wild flowers
Sunflowers are certainly worked by bees. But you bees will likely be better served by a diversity of plants, particularly those that flower in the off season (likely late summer / fall in most areas).
Here's a link that may be useful to you:
Note that even though you may have a large garden, bees will forage over a much wider area than just your property.
Your bees will be foraging in perhaps 8,000 acres surrounding their hive. Here's another suggestion for bee friendly plants, including some that flower late summer/fall:
According to Brother Adam he had bees he knew flew five miles or more to gather Heather nectar. According to Huber, he marked workers, took them different distances and released them and looked for them to turn back up at the hive. He said they always found their way back when they were 1 1/2 miles from the hive, but past that they didn't. He also says, and it makes sense, that it would depend on the foraging available. It also seems to vary by bee size. Brother Adam says his native Apis Mellifera mellifera, which were smaller, flew the five miles to get the Heather, but the Italians he replaced them with, which were larger, would not.
USDA Zone 7a - elevation 1400 ft