There are a lot of edible options for flowers. One of the most common in the the US are daylilies, the flower petals are sweet and crisp if a little dry at first. Roses are edible. Marigolds are but some types don't taste good. Many herbs have nice flowers.

If you want a veg garden also look at "scarlet runner beans" these are a climbing bean that become covered in red flowers which attract humming birds and bees galore. The flowers, leafs, and beans (both as green beans and dried) are edible. Some people grow these just for ornamental reasons.

Blueberries have a white flower almost shaped like a blueberry and, some types, will turn bright red in the fall. These can be a problem to grow if you don't have acidic soil though.

Earlier I said I was growing Echinacea. This is the same herbal supplement you can buy in a drugstore but you may also know as purple cone flowers.

There is a plant I have read about but not tried called Jerusalem artichoke which has a root similar to potatoes. The upper part of the plant looks just like a sunflower, including the 6' tall part.

Check this link out:Johnny Selected Seeds edible flower collection