Anything with an open-faced flower (ie accessible pollen) and not too rampant. Old fashioned flowers rather than modern hybrids generally fulfil these criteria. What you choose will depend on your zone. Mine are all self sowers. {{gwi:9264}} Opium poppy with red orach. Chard flowers on the left.

{{gwi:9266}} Shastas with rosemary, fennel and plum tree. Fava leaves in foreground left. Columbine seedheads too.

{{gwi:9268}} Nasturtiums and runner beans. (The latter very much a veggie over here, not an ornamental.)

I love growing flowers in my veggie garden. I use them to mark of different sections of the garden, for beauty, to attract hummingbirds, bees, butterflies, etc.

I use flowering herbs such as Bee balm (just put down some hammer-in edging or plant them in a large pot to keep them from taking over, garlic chives, pineapple sage, marigold. I also like to plant the old-fashioned tall zinnias, california poppies, and a variety of sunflowers in the garden. They self-seed and I move them around if they don't come up in a good spot.
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I have all sorts of flowers planted all AROUND the vege garden, but due to space, the only ones I have in with the veges are marigolds and nasturtiums. The nastutiums I love, but pull out like weeds all summer cause they TAKE OVER the garden here in zone 8ish!This year I pulled them all out and tossed them over the fence into the horse field next door to hopefully have them grow along the edge of the property (with the neighbor's consent, of course!)
I'm going to be adding more flowers this year now that I know what space I have to use. I'll also be adding giant sunflowers where I had corn last year.
Check out the potager garden board and the cottage board to see some really fabulous vege/flower combo's!

Here's my list of plants that I've grown over the years to attract and shelter beneficial insects. I vary the actual plantings from year to year. Some of these I plant in the vegetable beds and some I plant across the 18 inch path so that the beneficials don't have to travel far to enjoy their work:

Members of the daisy or aster family (Asteraceae) are excellent sources of pollen and nectar that attract beneficials including parasitic wasps, hover flies, green lacewings, and lady beetles: try annuals such as cosmos, marigolds, sunflowers, dahlias, or perennials such as coreopsis, tansy, golden marguerite, perennial sunflowers, goldenrods, coneflowers, and asters.

Members of the mint family (Lamiaceae) have aromatic foliage and two-lipped flowers that attract bees and hover flies: try annual basils or sweet marjoram and perennials such as thyme, mint, garden sage, catmints, Russian sage, and bee balms.

Memers of the carrot family (Apiaceae) with umbrella-shaped flowers attract lady beetles, hover flies, parasitic wasps, spiders, and lacewings: try annuals such as dill, caraway, and fennel; biennials such as Queen-Ann's-lace; and the perennial angelica.

You can also include a bug bath--a small dish of water with stones that beneficials can perch on.

If you plant an assortment of flowering plants with blooms times throughout the growing season, you can provide beneficials with a constant supply of food, not to mention, a full spring, summer and fall of color in the garden.

Here is a link that might be useful: HarvestToTable.com

And don't forget some vegetables have great bee and butterfly potential when they flower! Bees love it when my black seeded simpson lettuce flowers and the birds love it when it starts to seed. It does sometimes reseed in the garden, but it is welcome there.

Bees and butterflies were greatly attracted to my scarlet runner bean flowers...as an added bonus I also got to eat lots of beans both as snaps and dried. Since I garden mostly in the square foot method, I planted marigolds actually in with the veggies. Bees were also very attracted to the melon, squash and cucumber flowers. Dill and parsley attract swallowtails who will lay their eggs on them.

The hummingbirds were all over my scarlet runner beans this summer so I plan to plant more this next summer. We ate a few but were not impressed with their flavor.

I plan to do Companion Planting this year to see if it makes a difference.

My Russian Sage is planted in my front garden but I may move some of the new plants to the back gardens to encourage more bees.

The bees were all over the Holy Basil plants this Fall up to frost.

I have butterflies in my garden right now! They are after the few flowers that are still showing up on my Lavender Trailing Lantana.

Our gardens feed us...body and spirit.

Peggy

"Great Garden Companions" by Sally Jean Cunningham is a great book about planting flowers in the vegetable garden to attract beneficial insects for pest control and pollination. The book also covers which plants to grow together and other methods of discouraging pest and encouraging beneficial bugs.

I grow flowers to attract the right bugs both on the outer edges of the garden and interspersed with the vegetables. Some of my favorites are Bee balm, Tansy, Goldenrod, Fennel/Cilantro/Parsley allowed to bloom, marigolds, Alyssum, Mallow and Yarrow.

I've been amazed at the number of beneficial bugs in my garden (and the low number of pests).

Bellatrix

As Albert hinted at tangentially, don't forget that all veggies flower if allowed. So the easiest way to get flowers into the veggie garden is to do less than usual.

See what happens!

Parsnip in flower (a spectacular draw for pollinators):

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Letting carrots go to seed brings pollinators like crazy! I never saw such a feast before.

west texas peg - sorry you didn't enjoy the runner beans. Over here there are many named varieties bred for eating - my catalogue has 14 varieties. We eat them as green beans -I do not find them much good as shellies or dried beans. As far as I understand most runners sold in the US are generic 'Scarlet runners' not selected for eating. Also I suspect that your climate might not really let them give of their best.

And further to the comment about the value of flowering vegetables, don't forget that many flowers can be eaten. Nasturtiums, both leaves and flowers(which have different flavours), are a good addition to a mixed salad. But check first. Columbines, for example, are poisonous.

I grow flowers in my veggie garden for no better reason than I enjoy the aesthetics. With a few exceptions that I cannot bring myself to move, my veggie garden is limited to annuals only. I keep perennial edibles in my perennial beds. It is, for me, easier to care for them this way.

So, the flowers I choose for my veggie garden are inevitably annual. The big plus is that I can change it up every year. But, some things just work, you know? And so you stick with them. Marigolds are great between and under tomatoes. They are reliable and sturdy. Cosmos, large and small, are great for airy contrast and color. Lobelia are great low growing fillers and very easy to start from seed. Zinnia are great for cut flowers. Sunflowers are spectacular late season and are great for attracting birds when the seed is allowed to ripen, but can easily be overdone. Calendula are reliable re-seeders as is mallow - but mallow can be a bit bulky for smaller gardens. Milkweed is a favorite for butterflies and hummingbirds both.

However, as much as I love my flower/veggie gardens, having had veggie gardens both with and without flowers, I can say that I have never really seen any difference in the number of beneficials. I think that insects tend to go where the food is and if that food happens to be the bug that is eating your broccoli, then that is where the beneficial will go.

Personally, I think that a larger factor in attracting and keeping beneficials around is not what you plant, but how you plant it. Grouped plants with a good layer of mulch offer a lot more protection than neatly hoed rows. And everybody needs a home. Even bugs.

Kay.

I do, and I aim for edible flowers if possible. I recommend:

Chicory, or Italian dandelion - beautiful blue flowers on tall open stems.

Nasturtiums - the petals make a really pretty pesto sauce (replacing basil leaves).

Marigolds - the "Gems" are said to have the best flavor, I like other ones too, Queen Sophia, Tashkent, etc. You can use the petals in eggs, salads, sandwiches, etc.

Calendula - pet bunnies love these. We can eat the petals too or make a nice healing skin balm out of them.

Violas/Johnny-jump-ups and violets - edible. Some are fragrant.

Feverfew, lovely clouds of white single or double flowers (they come in both forms).

Pineapple sage, good for tea and the bright red flowers.

Lemon verbena, good for tea and the tiny sprigs of flowers are fragrant too.

Gladiolus - petals are edible.

Snapdragons - petals are edible.

Dianthus/Pinks, Carnations - edible. Most are fragrant too.

Alyssum - petals are edible, flowers waft a honey fragrance.

Single roses - I grow species Rosa arkansana "Peppermint," "Secret Garden Musk Climber," "Louise Clements" and a few others.

Scented leaf geranium/pelargoniums have useful (edible, tea, potpourri) foliage and pretty flowers too.

Hibiscus (tropical) - parrots like to eat these (I have one) and there is one you can make tea from the calyxes H. sabdariffa or roselle.

Jasmine, you can flavor tea with the flowers.

Opium poppies - gorgeous, some are breadseed sources (harvest the seedheads before they burst, otherwise they reseed themselves, not so bad).

I admit, I like and grow "poisonous" flowers too: Plumeria (dogbane family), daffodils, Angel's Trumpets, Plumbago, Iris and more.

There are so many, I don't think you can go wrong just look through a catalog or your local nursery and pick what you like.

Thank you, everyone, for all the great suggestions! I can't wait for planting season! I'll refer back to your lists as I draw up my plans.