So you’re a flower grower, not a vegetable grower. Vegetables are actually easier to grow, taste better than grocery store purchases and do not have poisons on or in them (unless you do it). The seeds are cheaper than nursery plants, though granted your produce will be more expensive than in-season store bought vegetables when you consider your time and energy spent - but much more satisfying to eat.
Do not picture acres of row on row of vegetables which means you must harvest, clean, freeze and store vast quantities of produce. Eating cabbages, beans and potatoes until you turn green. No. Simply interplant only your favourites amongst your flowers. Perhaps a pepper or tomato plant. A few radishes, beets, swiss chard or red Russian kale. (In France I saw dill waving in the breeze interplanted with the flowers in the boulevards and rosemary hedges.)
Seed companies now sell many vegetables that grow only to mini sizes. You could even have little carrots in your planters so that you have pretty feathery green leaves. Consider that garlic is a companion plant to roses. Since the former must be planted in the fall you can get it into the ground when you hill up those roses. A 12 inch pot of mesclun (mixed lettuces) is very attractive and will supply you with plenty of salads. Just keep picking those outside leaves and remove any blossom stems.
Vegetables are healthy food. They are better tasting than lilac blossoms, violets and day lily flowers. But I must admit nasturtium leaves should be given a chance by dedicated vegetable growers.
Have fun gardening.