Biennial Herbs and Greens for a Self-Sustaining Garden

There are many biennial flowers, but some popular herb- and vegetable-garden plants are also biennials. Though they’re typically grown as annuals for their leaves or edible roots, they can survive winter and return the following season. They’ll no longer be edible in the same way, but they’ll bloom profusely and, best of all, provide a crop of seeds to collect.

After the second year, the plant dies, but if the seeds are allowed to scatter on the soil, they’ll sprout anew come spring. If the cycle is broken at any point—the flower stalks are removed from the plant before the seeds form, or the dispersed seeds are raked or blown out of the beds—the biennial will disappear.

Related: How to Grow Biennial Flowers and 6 Garden Favorites

Found growing wild in the cliffs above the Mediterranean Sea, parsley (Petroselinum crispum; Zones 2–11) is one of the easiest plants to grow in your home garden. With a 12-inch height and spread, this low-maintenance herb performs well in sun to part shade and consistently moist soil. It has few serious issues with pests and diseases, but excessive heat and humidity will stunt its growth. Because germination can be slow and uneven, it’s best to buy parsley seedlings. 

The leaves can be harvested well into winter, until temperatures in the 20s (F) cause the plant to go dormant. Emerging the following spring, second-season parsley plants will taste bitter. So the plants can be left to grow, flower and set seeds. The showy umbels of greenish yellow blooms, held on two- to three-foot-tall stalks, are especially attractive to black swallowtail butterflies. 

I grow parsley as an embedded edible in my ornamental gardens and containers. The first-year foliage makes a wonderful filler, and the second-year flowers are highlights of the summer garden.  

Related: Herbs to Grow in Ornamental Gardens

Sweet fennel (Foeniculum vulgare; Zones 4–9) is another Mediterranean native that thrives in moist, organically rich, well-drained soil. In full sun, its upright branching will easily reach six feet tall and spread three feet wide. Fennel is grown primarily for its anise-flavored leaves and seeds.

Second-season fennel produces tiny yellow flowers in large, flattened, compound umbels that emerge among the feathery foliage from mid- to late summer. These flowers attract butterflies, especially swallowtails, making fennel a great addition to any pollinator patch. After the bloom, the aromatic seeds develop and readily self-sow—be prepared for it to naturalize in suitable sites. 

I’ve grown fennel as the “thriller” in container combinations and in beds outside the veggie garden fence. Deer are repelled by the pungent scent and taste of its foliage.   

Related: Uncommon Herbs to Grow at Home

Descendants of the Afghanistan-native wild carrot (Daucus carota var. carota), or Queen Anne’s lace, garden carrots (D. carota var. sativus cvs.) grow best in loose, fertile, well-drained soil and full sun, although they can take a little light shade. Raised beds of sandy loam produce the most perfect roots; rocky or clay soils will distort them. That said, I’ve used carrots to help rejuvenate the soil in difficult sites, treating them not as an edible plant there but as a biennial cover crop.

The roots will become inedible if allowed to winter in the garden, but their new shoots will bloom in umbels of tiny white flowers from early summer into fall, amid basal foliage with a striking lacy look. Remove the spent blooms or diligently collect the seeds to avoid the spread of this somewhat aggressive volunteer. 

A member of the beet family, Swiss chard (Beta vulgaris var. cicla; Zones 2–11) descended from the wild sea beet (B. v. subsp. maritima) found along the Mediterranean and Atlantic coasts of Europe. Swiss chard made its way into gardens as a unique leafy green. It grows best in well-drained, organically rich, light to sandy soils in full to part sun. With consistent moisture, it develops upright clumps of foliage to two feet tall and almost as wide.

Cultivars like ‘Bright Lights’ and ‘Northern Lights’ are prized for the striking multicolored petioles and midribs that lend them to ornamental use. If left to grow a second season, Swiss chard will develop small greenish flowers in dense spikes on four-foot stalks. Unopened buds are edible. 

Swiss chard will continue to grow even as temperatures drop into the 20s. For this reason, I always use them in autumn container combos. And I have included them in my flower beds and borders for years—one of my original embeddable edibles.

Photos by Jack Coyier

Daryl Beyers is a garden designer, writer, speaker and educator based in Shasta County, Calif. His latest book is The New Garden Designer’s Handbook (Timber Press, 2026).

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