Most of us eliminate dandelion from our gardens, as we call it a weed,but in fact most parts of it are edible. I have read different opinions of the stem. Some say that no plant with a milky sap in the stem is edible, but others make an exception for dandelion. I have played it safe by never eating the stem, but I have consumed dandelion leaves in salad, finding them tasty, and I have made their flowers into wine. Just a word of advice here, two glasses of it make you want to urinate! The roots of dandelion used to be picked to make dandelion coffee.
One common garden flower that was originally introduced as an edible is the dahlia. Its great variety of flower shape conceals the fact that it is related to the daisy and the sunflower, and we know that the latter produces edible seeds. Dahlia petals can be used in salads, but use only the petals,not the reproductive organs. The bulbs are edible. Initially they taste like celery, though they become sweeter with storage. Tuberous begonias are also edible,you can eat the leaves, flowers and stems. However, those with gout, rheumatism or similar conditions should avoid eating begonias as they contain oxalic acid.
The Rosaceae, the huge family to which roses belong contains a great variety of edible plants, including apples, pears and quinces,as do plums, damsons and cherries. Rose petals can be added as a garnish to salads, though darker cultivars are said to have the stronger flavour. These petals can be used to provide a subtle flavour to a homemade wine. Take a pint of petals, soak them for three days and then add sugar, yeast and yeast nutrient. Leave to ferment out and mature.Some cooks garnish ice cream with rose petals. Rose hips, the little swellings behind the flower are full of vitamin C, they are made into rosehip syrup,but the seeds inside have to be filtered out as they are an irritant. This syrup can be made in a domestic kitchen.
Some other members of the Rosaceae are eaten or drunk. Potentilla repans, cinquefoil, has petals that are brewed into a herbal tea. Another member of this family is Potentilla anserina, sometimes known as Argentina anserina, popularly called silverweed, is known for its edible tubers. Before the advent of the potato silverweed was a staple food in the Celtic regions of the British Isles, where it was known as the seventh bread.