There are quite a few flowers as you'll see below that can decorate and enhance the flavour of dishes and salads. In every season there are flowers to be used. The flowers of the culinary herbs are great to use for this purpose, the taste of the flower is often slightly stronger than the leaf. For example:
Basil (Ocimum basilicum), Beefsteak plant/Shiso (Perilla frutescens), Caraway (Carum carvi), Chervil (Anthriscus cerefolium), Chives (Allium schoenoprasum), Cumin (Cuminum), Dill (Anethum graveolens), Giant Hyssop (Agastache foeniculum), Lemon verbena (Aloysia triphylla), Marjoram (Origanum vulgare), Mint varieties (Mentha ssp.), Rosemary (Rosmarinus officinalis), Sage (Salvia officinalis), Savory (Satureja montana), Tarragon (Artemisia dracunculus), Thyme (Thymus vulgaris), Wild Thyme/Creeping Thyme (Thymus serpyllum).
Other garden flowers, many of them herbs, that look very attractive and are tasty:
Borage (Borago officinalis), Courgette (Cucurbita pepo), Clover (Trifolium), Daisy (Bellis perennis), Dandalion (Taraxacum officinalis), Daylily (Hemerocallis), Evening Primrose (Oenothera biennis), Fuchsia (Fuchsia), Hollyhock (Alcea Rosea), Honeysuckle (Lonicera), Horsemint (Monarda), Hyssop (Hyssopus officinalis), Lavender(Lavender), Mallow (Malva sylvestris), Marigold (Calendula officinalis), Nasturtium (Tropaeolum majus), Pelargonium/scented (Pelargonium ssp), Pansy (Viola), Poppy (Papaver), Rocket (Eruca vesicaria), Rose (Rosa ssp), Sunflower, flowers in August/seeds in September (Helianthus), Violet/sweet (Viola odorata).