Remember that old joke from when we were kids? When is a door not a door? When it is ajar. Get it?
So when is an herb not an herb? The answer is, when it is a vegetable. A perfect example of an herb that also is a vegetable is fennel.
I can't say I have a lot of experience with fennel other than growing it. I love its pungent anise-like fragrance. I've grown the bulbs - technically not really bulbs - of annual Florence fennel and I've grown common fennel, a perennial used for its leaves and seeds.
Common fennel, Foeniculum vulgare, is the perennial that comes back every year. I particularly loved the bronze variety because it was more interesting and ornamental, although all fennel types have the same anise flavor and fragrance.
Although it, too, is classified as an herb, annual fennel, Foeniculum vulgare azoricum - in Italy it is called Finocchio - has an enlarged stem near the base of the plant that sits on top of the soil. It is this enlarged stem, commonly called a bulb, that is eaten as a vegetable.
Although both plants are called fennel with only a slight change in the botanic name to separate the two, for the sake of avoiding confusion, I will call them herb fennel and vegetable fennel.
Vegetable fennel, also called Florence fennel, is a tender perennial that we grow as an annual. It is extremely easy to grow. I start my plants from seeds sown indoors in early spring. After the last frost, I put the plants in an area that gets full sun. When the bulbs start to form near the soil line, like celery or cauliflower, I cover them with mulch to keep them nice and white. Some growers prefer to let the bulbs get hit with the first light frost before harvesting, but I harvest them as soon as they are about the size of golf balls. Too many frosty nights will kill the plant, as they don't like our cold winters.
Herb fennel is a hardy perennial that not only withstands our winters, but can readily reseed itself all over the garden. To keep seeds from blowing away or possibly landing in areas where you don't particularly want fennel next year, cover the seedheads with paper bags secured loosely with rubber bands or string to capture the seeds. Herb fennel has a lot of taproot and doesn't take well to transplanting, so I sow those seeds directly in the garden where they will grow all season.
Fennel is at home either in the vegetable or the herb garden as long as the soil is rich, they are in the sun, and they get enough water. The soil should be well-drained, but plants should be watered at least twice a week and they shouldn't be allowed to dry out for long periods of time. Once the seeds germinate, thin them to about 10 to 12 inches apart. The plant will cross-pollinate with dill, which could render the seeds flavorless, so take that into consideration when planning the layout of your garden.
Like parsley, a fennel cousin, leaves of either variety can be harvested at any time, although vegetable fennel leaves aren't as pungent as herb fennel. Leaves are most often used to season soups and sauces as well as homemade salad dressings. Seeds are used to season savory dishes, particularly Italian dishes and German food, such as sausage.
Vegetable fennel bulbs can be sliced and eaten raw or cooked into dishes. The bulbs are common ingredients in Italian antipasto or baked into fish or potato dishes. They retain their anise flavor when cooked and some say also have a faint celery taste as well.
If you haven't tried growing fennel, you might want to add this plant to your list for next season.