Growing Fennel

Growing Fennel: fennel fronds in the garden

image from iStock

Fennel is a beautiful herb to have in the garden. Feathery and fern-like, it adds both color (the variety Bonnie carries is a striking reddish-bronze) and texture to your plantings. It also boasts a strong, licorice-like flavor. Fennel is a tender perennial, which means the plant may make it through the winter in warm areas, but is sensitive to cold. Most gardeners grow fennel as an annual.

Soil, Planting, and Care

Fennel prefers soil that is fertile and drains well. Before planting, enrich the soil by mixing in compost or other organic matter. Fennel is a sun-loving plant, so plant it where it will receive at least 6 hours of direct sun.

Growing Fennel: fennel in an herb garden

Fennel makes an eye-catching backdrop to lower growing herbs in an herb garden.

Plant fennel after the last spring frost. This plant can tolerate light frosts, but needs protection when young. Use a frost cloth to cover. When planting, space fennel seedlings from 4 to 12 inches apart, depending on variety. (Check the plant tag for more information.)

Be sure to keep soil consistently moist. Water regularly, giving plants at least an inch of water per week (more in hot weather). Stick your finger into the soil to check moisture; if the top inch is dry, it’s time to water.

At planting, give your fennel a boost of nutrition with a liquid plant food such as Bonnie Herb, Vegetable & Flower Plant Food. Continue to feed every 7 to 10 days, following label directions.

Once blooms begin to appear, you can either pinch them to prevent the plant from going to seed, or just go ahead and let it flower, to attract beneficial insects

Troubleshooting

The main pest that seems to bother fennel is the parsleyworm, which looks like a green caterpillar with black and yellow bands. Check leaves regularly, and hand-pick worms as soon as you see them, to prevent them from eating the foliage. Or consider leaving them be, if you don’t mind sharing your harvest. Parsleyworms turn into black swallowtail butterflies, which are good pollinators.

Growing Fennel: fennel bulb in soil

Some varieties of fennel are grown for their leaves, and others for their bulbs. image from iStock

Harvest and Storage

You can harvest fennel leaves anytime during the growing season – the more you trim it, the bushier it will become, leading to more and bigger harvests for you. Be sure not to trim more than a third of the plant when you harvest. Some types of fennel also produce bulbs, which can be harvested once they measure several inches across. Leaves can be kept on the counter with cut stems in a glass with water. Unwashed bulbs can be kept in the refrigerator for 3 to 5 days.

Uses

Leaves and seeds have a sweet anise flavor, somewhat like licorice. Use leaves in salads, coleslaw, soups, and stews. Bulbs can be sliced for use in salads and side dishes, or roasted to mellow the strong flavor. Fennel flowers are edible, and make wonderful garnishes for fish, meat, potato, and tomato dishes. Fennel stems also look wonderful in fresh bouquets.