A subject I have been interested in for several years is that of edible flowers. You will be amazed at how many common (and some uncommon) flowers from your garden are edible. In our own garden we have planted edible herbs and flowers in random mixes. They not only look beautiful in the garden beds, but they also look beautiful when you use them in salads and such. You can even use flowers in desserts or to garnish tea sandwiches and finger cakes (petit fours)!
Before you go and taste a flower to see if it is edible, you need to know a little bit about the plant's family. Some flowers and plants are poisonous, so care should be taken in selecting. Some edible flowers will not grow in all areas.
Photo: Borage blossoms - planted at the Mala'ai School Garden in Waimea
Many herbs and flowers are also medicinal, so it should not come as too much of a surprise that they can be also eaten as food.
One main thing to remember when you plant a garden of herbs and edible flowers is that you should never, ever, use chemical fertilizers or pesticides!!
Photo: Garlic Chive blossoms, in our garden
You can use organic fertilizers (cured manure and composting) and pesticide sprays that you can make yourself, such as chopping garlic and hot peppers and mixing with water in a spray bottle or do companion planting, such as mixing marigolds (some pests seem to stay away from them) and other flowers around your other plants. The marigold petals are edible, by the way. (check out the info on Companion Planting with Flowers - link below)
Photo: Mini Daylily in our garden
Many edible flowers will reseed themselves like crazy, so you should always have a plentiful supply. The most prolific is the nasturtium. The Empress of India, which is a dark jewel red color has a spicy, peppery flavor, and both the blooms and leaves are wonderful in mixed salads.
The following site has a very comprehensive list and other links for information on both edible flowers and the ones to avoid.
Photo: Pineapple Sage blossoms, in our garden