Fennel is a beautiful herb to have in the garden. Feathery and fern-like, it adds both color 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. Be sure to look for vigorous young fennel plants from Bonnie Plants®, the company that has been helping home gardeners succeed for over a century.
Quick Guide to Growing Fennel
- Plant fennel in spring after the last frost. It’s a great option for growing in raised garden beds, containers, and in-ground gardens.
- Space fennel plants 4 to 12 inches apart, depending on the variety. Grow them in an area that gets at least 6 hours of sun and has fertile, well-drained soil.
- For best results, improve your native soil by mixing in several inches of aged compost or other rich organic matter.
- Promote excellent leaf production by regularly feeding with a water-soluble plant food.
- Keep soil consistently moist and water when the top inch of soil becomes dry.
- Harvest fennel leaves anytime, but avoid trimming more than one-third of the plant at once.
Soil, Planting, and Care
Fennel prefers soil that is fertile and drains well. Before planting, enrich your existing soil by mixing in compost or Miracle-Gro® Performance Organics® All Purpose In-Ground Soil. If growing in pots, fill them with Miracle-Gro® Performance Organics® All Purpose Container Mix. Both Miracle-Gro products are enriched with aged compost and provide just the right organic nutrition to get plants off to a strong start. Fennel is a sun-loving plant, so plant it where it will receive at least 6 hours of direct sun.
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.
For best results and super-strong growth, you’ll want to build on the nutritional foundation provided by starting with great soil. Regularly throughout the growing season, give your fennel and other plants (as well as the beneficial microbes in the soil) a boost of nutrition, once a week, with a water soluble plant food like Miracle-Gro® Performance Organics® Edibles Plant Nutrition. Continue to feed every 1 to 2 weeks, 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
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.
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.
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.