Be Careful of Fennel’s Evil Twin

Question: When I walk in Newport’s Back Bay, I often see plants that look like the fennel I use in cooking. Is that possible?

H.M., Newport Beach

Answer: It may well be fennel (Foeniculum vulgare), a carrot-family member, but be careful. Poison hemlock (Conium maculatum) resembles fennel. Both are originally from Europe, are naturalized in California and grow in similar places.

Poison hemlock can easily kill an adult if as little as a spoonful of seeds or leaves are ingested. The ancient Greeks used poison hemlock to kill political prisoners, including Socrates.

Fennel has a definite licorice scent but no purple spots on the stalks; poison hemlock does not smell of licorice and does have purple blotches. Because of the possibility of confusion between these two plants, it is best to avoid using fennel found growing in the wild and grow your own from seed or plants found at the nursery.

Fennel is one of several hundred healing plants named in Hippocrates’ writings. Ancient Egyptians, Hindus and Chinese used its seeds for spices. It was introduced into North America by Spanish priests and still grows wild around old missions. Mission priests would spread fennel stems on the floor so the pleasant aroma was released as the congregation entered.

Used extensively in French and Italian cooking, fennel is totally edible. You can snip the lacy leaves as soon as they are large enough and use them as a flavorful, aromatic addition to salads and other cold dishes. The bulbous root can be sliced and added to salads or cooked as a root vegetable. Young, tender stems can be eaten raw or cooked. Raw, fennel resembles anise-flavored celery; cooking dissipates much of the anise flavor.

Seeds are stronger flavored and lend an anise taste to baked goods, fish, meat, cheese and vegetable dishes. The sweetness of whole fennel seed is an integral part of herbes de Provence. Tea can be made of the seed or leaves.

Not only is it tasty, but fennel also is great for the garden. The herb is attractive to bees, aphids, beneficial insects and birds. In some areas, beekeepers grow it as a honey plant.

Beneficial insects, such as lacewings and ladybird beetles, feed on fennel pollen and nectar when aphids are not available. Birds feast on the seeds, as well as the variety of insects harbored by the plants.

Now is the time to plant fennel, either from seed or nursery transplants. There are at least three cultivars available.

Common fennel (Foeniculum vulgare) has small, yellow summer flowers and lime-green leaves. Others include Bronze fennel (‘Rubra’), which has striking feathery pink, copper and bronze leaves. Florence/finocchio fennel (F.v. azoricum) is often grown for its bulbous rootstalk.

Cooked, the base has a light delicate anise flavor that makes a good counterpart to fish, fowl and bland meats such as veal.

Here are some planting tips:

* Plant in full sun in a light, well-draining soil. A heavy soil will yield poor results with Florence fennel. For a continuous supply of fresh leaves, make successive sowings in two-week intervals. For a quicker harvest next year, scatter seeds in autumn for early spring germination.

* Thin plants when 1 to 2 inches high. They should be spaced 1 foot to 18 inches apart.

* Although tolerant of dry, hot weather, fennel appreciates regular watering.

* Harvest stems and leaves only as needed, as the stems and leaves rapidly lose quality in storage. Gather seeds in autumn when the seed heads turn brown and the stalks start to wither.

* Florence fennel requires one additional step to prepare its thickened base for use as a vegetable. When the base reaches the size of a large egg, gather soil up around it to blanch it. A month later, it will be ready for harvest. Loosen the surrounding soil with a spading fork and carefully lift the plant out of the ground.

--Researched and written by Mary C. Steele of Laguna Niguel. She is a UC master gardener in training.

Have a problem in your yard? University of California Cooperative Extension (UCCE) Master Gardeners are here to help. These trained and certified horticultural volunteers are dedicated to extending research-based, scientifically accurate information to the public about home horticulture and pest management. They are involved with a variety of outreach programs, including the UCCE Master Garden hotline, which provides answers to specific questions. You can reach the hotline at (714) 708-1646 or send e-mail to [email protected]. Calls and e-mail are picked up daily and are generally returned within two to three days.