Flowering herbs do more than add beauty to the garden. They can be used in the home and kitchen as well. The planting zone is determined by the coldest temperatures in the winter. These three flowering herbs can grow in all but the coldest and hottest parts of the United States.
Anise hyssop has very small lavender-blue flowers that bloom in late summer, leaves that taste like anise and stems that taste like peppermint. The leaves are used to make tea and the flowers are used in fruit salad. It attracts bees and can be dried and used in dried flower arrangements. It is hardy in zones 4 to 9 and reaches a height of 2 to 4 feet and width of 1 foot.
Purple coneflower is a perennial. It will die back to the ground in the winter but grow again in the spring. When mature, the plant can be 3 feet tall and 3 feet wide. The flowers look like daisies and can be up to 3 inches across. The stems are long enough for the flower to be used in arrangements. It is a native of North America and is hardy in zones 3 to 9.
Rue is an evergreen perennial that will grow from 2 to 3 feet in height and about the same in width. It produces clusters of small yellow flowers in midsummer and is native to southern Europe and northern Africa. Use too much rue and the taste will be bitter, but just a little bit added to products like cream cheese, salads and eggs will give the dish a pleasant, musky taste. Dry and crush the leaves and you have an insect repellent. However, some people are allergic to rue. Just touching it can cause a rash, and consuming even a tiny bit can make them sick and extra sensitive to sun. Rue is dangerous for pregnant women. Rue is hardy in zones 4 to 9.