People with home gardens often set aside space for both herbs and vegetables. When starting a fennel crop, you can easily establish it in either plot.

There are two main varieties of fennel, one of which can be treated as an herb and one of which can be treated as a vegetable. The University of Illinois Extension says herb fennel is grown for its lacey leaves along with stems and seeds. Vegetable fennel, or Florence fennel, features an edible "bulb," which is actually a rosette of petioles.

Fennel requires a good amount of space in the garden. The Cornell University Cooperative Extension says plants can grow up to six feet tall, and individual ones may spread up to three feet.

Both the herb and vegetable types of fennel have an anise flavor, allowing you to lend a licorice-like taste to your dishes. Although the plant is considered a short-lived perennial, it is typically grown as an annual in areas with cold winters.

Planting

The best time to plant fennel seed depends on which variety you are using. The University of Illinois Extension says it is best to sow herb fennel seeds in the spring. Florence fennel should be planted in midsummer so it can develop during the cooler, shorter days later in the season.

Both types of fennel prefer areas with full sunlight. The gardening company Bonnie Plants says fennel should be planted in rich, well-draining soil which has been amended with compost. The Cornell University Cooperative Extension says fennel can tolerate a wide range of pH levels, from about 4.8 to 8.2, and can also tolerate droughty soil.

Check the variety of fennel you are growing for recommendations on how far apart the seeds should be planted. Mark MacDonald, writing for West Coast Seeds, says fennel seeds should generally be planted about half an inch deep. Seedlings can later be thinned so they are about 12 inches apart.

Fennel can be directly sown in a garden plot, but can also be grown in containers. Colleen Vanderlinden, writing for the home design site The Spruce, says containers should be at least 10 inches deep.

Avoid growing fennel as a companion crop. It can inhibit the development of other plants, especially tomatoes and beans.

Care

Fennel is a relatively maintenance-free crop. Bonnie Plants says the plant should be watered regularly so it receives at least an inch of water per week. Avoid overwatering by first checking to see if the top inch of soil is moist.

Although it can tolerate light frosts, fennel is more vulnerable to damage from the cold when it is young. Frost cloth can help protect the plant during its early growth.

Fertilizer is not strictly necessary. However, fennel may benefit from applications of liquid plant feeder.

Cutting back the plant can force it to become bushier. The Cornell University Cooperative Extension says you can also stake fennel if it becomes too leggy.

Fennel will readily self-sow, which can be useful for establishing plants in the following season. However, the plant can easily become weedy if too much seed drops. Remove at least some of the plant's flowers before they begin to set seed.

You may want to remove some of the seeds to plant at a later time. Vanderlinden says you can simply shake the seeds onto a sheet or tarp, then allow them to dry before storing them.

Few pests will affect fennel, although you may need to remove aphids or slugs during the growing season. Bonnie Plants says parsleyworms, which look like green caterpillars with black and yellow stripes, may snack on the plant's leaves. You might consider leaving these in place instead of removing them, however; they will later turn into black swallowtail butterflies, which are beneficial pollinators.

Diseases are also rarely an issue for fennel. The Cornell University Cooperative Extension says the plant may be affected by leaf spot, mycoplasma, or powdery mildew.

Once the first hard frost occurs in autumn, fennel should be cut back to ground level.

Harvesting

When you trim back fennel to make it bushier, the leaves can be used in various recipes. Bonnie Plants says you shouldn't remove more than one-third of the plant at any time.

Florence fennel can be harvested once the bulb has swollen to a sufficiently large size. The University of Illinois Extension says that once the bulbs are about as large of a tennis ball, they can be dug up and stored in a cool place.

Fennel leaves work particularly well in soups and salads. Seeds can also be used in some food preparation, such as adding flavor to sausage.

Bonnie Plants says fennel bulbs can be sliced and eaten raw on salads or in side dishes. Bulb slices can also be roasted for a mellower flavor.

After deadheading the plant, flowers can be used as edible garnishes in several dishes. Stems may be used as a non-floral addition to flower arrangements.