Plants follow many different life cycles, but few are as intriguing as the biennial. Unlike annuals that complete their entire life — germination, flowering, seed production, and death — in a single growing season, or perennials that persist year after year, biennials take a slower, more deliberate path. They spread their life cycle across two full years, investing the first year in growth and the second in reproduction.
In their first year, biennial plants focus entirely on vegetative development. They germinate from seed, establish a root system, and produce a rosette of leaves or a leafy stem, but they do not flower. They then enter a period of dormancy over winter. In the second year, they bolt upward, flower, set seed, and die — their single reproductive act complete.
Biennial plants are found across a remarkable range of families and habitats. Of the approximately 400,000 known plant species on Earth, true biennials represent a relatively small but ecologically significant group. Studies suggest that biennials are especially prevalent in the carrot family (Apiaceae) and the cabbage family (Brassicaceae), two of the largest flowering plant families in the temperate world.
Economically, biennials punch well above their weight. Several of the world’s most important root vegetables — including carrots, parsnips, and beets — are biennials grown as annuals, harvested in their first year before they ever flower. The global carrot market alone was valued at over $17 billion USD in 2023. Meanwhile, biennial wildflowers like foxglove and hollyhock have been garden staples for centuries, and plants like clary sage and evening primrose have found roles in perfumery, medicine, and food science.
Gardeners working with biennials must plan across two seasons, which makes these plants unique in the horticultural calendar. Many gardeners sow biennials in summer so that seedlings are ready to overwinter and bloom the following spring. Some species — notably foxgloves and wallflowers — have become so beloved that they are among the most widely grown cottage garden plants in the world.
1. Common Foxglove (Digitalis purpurea)
One of the most iconic biennial wildflowers, foxglove is native to western and central Europe and thrives on woodland edges, roadsides, and disturbed ground. In its first year it forms a large, soft rosette of downy leaves. In the second year it sends up a tall spike — often exceeding 1.5 metres — covered in tubular, purple-pink flowers with spotted throats. It is the original source of digitalis, a compound still used in heart medication today.
2. Wild Carrot (Daucus carota)
The ancestor of the cultivated carrot, wild carrot is a biennial native to Europe and Southwest Asia that has naturalized across much of the world. In year one it produces feathery, finely divided leaves and a white, woody taproot. In year two it sends up a tall stem topped with flat, lacy white flower clusters (umbels), often with a single dark red floret at the centre. It is a key nectar source for many insects.
3. Common Mullein (Verbascum thapsus)
A strikingly architectural plant, common mullein forms a dense rosette of large, woolly, grey-green leaves in its first year. In the second year it sends up a stout, erect spike that can reach 2 metres, bearing densely packed yellow flowers. It is native to Europe and Asia but has spread widely as a roadside plant. Historically, the dried stalks were dipped in fat and used as torches.
4. Hollyhock (Alcea rosea)
A beloved cottage garden classic, hollyhock is believed to have originated in southwestern China and the Middle East. Its first-year rosette is unremarkable, but in the second year it produces tall, upright stems — sometimes over 2 metres — laden with large, showy flowers in shades of white, pink, red, purple, and near-black. It has been cultivated in European gardens since the fifteenth century.
5. Parsnip (Pastinaca sativa)
The parsnip is a biennial root vegetable native to Eurasia. Gardeners harvest its sweet, cream-coloured taproot at the end of the first growing season, before the plant flowers. Left in the ground, it will bolt in spring of the second year, producing tall stems with yellow umbel flowers. The leaves and sap can cause phototoxic skin burns, so handling in bright sunlight is best avoided.
6. Beet / Beetroot (Beta vulgaris)
Although typically grown as an annual for its swollen root or leaves, beetroot is botanically a biennial. In its natural cycle it stores energy in a fleshy taproot during year one, then flowers and sets seed in year two. It belongs to the same species as sugar beet, which provides roughly 20% of the world’s sugar supply. Beetroot has been cultivated since ancient times and has diverse culinary uses across Europe, the Middle East, and beyond.
7. Wallflower (Erysimum cheiri)
One of the great harbingers of spring in temperate gardens, the wallflower is a short-lived biennial or perennial native to the eastern Mediterranean. Its clusters of fragrant flowers in shades of yellow, orange, and red appear in early spring of its second year, often on old walls, rocky outcrops, and coastal cliffs. It is so associated with English cottage gardens that it is now a UK national plant favourite.
8. Sweet William (Dianthus barbatus)
Sweet William is a popular garden biennial (sometimes grown as a short-lived perennial) from southern Europe and parts of Asia. In its second year it produces dense, rounded clusters of small, fringed flowers in combinations of red, pink, white, and bicolour. It has a light, clove-like fragrance and attracts butterflies and moths. It has been grown in European gardens since at least the sixteenth century.
9. Evening Primrose (Oenothera biennis)
Native to North America, evening primrose is a classic biennial that forms a ground-hugging rosette in year one before sending up a tall flowering spike in year two. Its large, bright yellow flowers open in the evening and are pollinated by moths. The seed oil is rich in gamma-linolenic acid (GLA) and is commercially harvested for use in dietary supplements and cosmetics worldwide.
10. Clary Sage (Salvia sclarea)
A biennial herb from the Mediterranean and Central Asia, clary sage develops a broad rosette of large, rough-textured leaves in its first year. In the second year it produces tall, branching spikes of lilac and white flowers with prominent bracts. The plant is grown commercially for its essential oil, which is widely used in perfumery, flavouring, and aromatherapy. It has a warm, musky, slightly nutty scent.
11. Black-Eyed Susan (Rudbeckia hirta)
While often treated as an annual or short-lived perennial, black-eyed Susan behaves as a biennial in many environments. Native to the prairies and open woodlands of North America, it produces a leafy rosette in year one and golden-yellow daisy flowers with a dark brown central cone in year two. It is a major source of nectar for native bees and has become a widely planted wildflower garden species.
12. Dame’s Rocket (Hesperis matronalis)
A fragrant biennial from Europe and Asia, dame’s rocket is grown in cottage gardens for its clusters of purple, pink, or white four-petalled flowers that bloom in late spring. It is often confused with garden phlox (which has five petals). The flowers are especially fragrant in the evening. It has naturalised widely in North America, where it grows along roadsides and stream banks.
13. Canterbury Bells (Campanula medium)
A favourite Victorian cottage garden plant, Canterbury bells is a biennial native to southern Europe. In its second year it produces large, bell-shaped flowers in shades of blue, purple, pink, and white on upright stems up to 80 cm tall. The flowers are distinctive for their inflated, cup-and-saucer form, particularly noticeable in the cultivar calycanthema. It is named after the city of Canterbury in England.
14. Teasel (Dipsacus fullonum)
Teasel is a dramatic biennial native to Europe and Asia, recognisable by its tall, prickly stems and egg-shaped flowerheads ringed with small lilac-pink flowers. In year one it forms a basal rosette; in year two it can reach 2 metres. The dried seedheads provide winter food for goldfinches and are popular in floral arrangements. Historically, the dried heads were used to raise the nap on woollen cloth.
15. Honesty (Lunaria annua)
Despite its species name, honesty is a biennial rather than a true annual. It is native to the Balkans and Southwest Asia but has been grown in European gardens for centuries. In its second year it bears clusters of purple or white four-petalled flowers, followed by distinctive, flat, silver-translucent seed pods that are beloved in dried flower arrangements. The pods give the plant its alternative names: “silver dollar plant” and “moonwort.”
16. Ragwort (Jacobaea vulgaris / Senecio jacobaea)
Common ragwort is a biennial or short-lived perennial native to Europe and Asia. It forms a rosette in year one and produces branching clusters of bright yellow daisy-like flowers in year two. Though toxic to horses and livestock if consumed in large quantities, it is one of the most important plants for wildlife in temperate Europe, supporting over 30 specialist insect species, including the cinnabar moth, whose caterpillars feed exclusively on it.
17. Greater Burdock (Arctium lappa)
Greater burdock is a robust biennial native to temperate Asia and Europe. Its first year produces enormous, heart-shaped basal leaves. In year two it sends up stout, branching stems with purple thistle-like flowerheads enclosed in hooked burs that cling to passing animals and clothing — the inspiration for the invention of Velcro. In East Asia, the root (gobo) is an important vegetable prized for its earthy flavour and health properties.
18. Wild Parsnip (Pastinaca sativa subsp. sylvestris)
The wild form of the parsnip is a biennial of roadsides, meadows, and disturbed ground across Eurasia. Like its cultivated relative, it forms a rosette in year one and flowers in year two, producing flat-topped yellow umbels. The sap of the stem and leaves contains furocoumarins, which cause severe skin burns in sunlight — a condition known as phytophotodermatitis. It has become an invasive roadside weed across much of North America.
19. Siberian Wallflower (Erysimum × marshallii)
A hybrid biennial derived from Erysimum perofskianum, the Siberian wallflower is a popular garden plant known for its vivid orange flowers that appear in spring of the second year. It is hardier than the common wallflower and tolerates harsher conditions. It is often mass-planted for spring bedding displays and is a valuable early nectar source for bees and butterflies emerging from winter.
20. Viper’s Bugloss (Echium vulgare)
A biennial of dry, rocky, and coastal habitats across Europe and Asia, viper’s bugloss forms a bristly rosette in year one and produces tall spikes of vivid blue funnel-shaped flowers in year two. The flowers are exceptionally rich in nectar and are among the most visited flowers by bumblebees in temperate Europe. It gets its unusual name from the resemblance of its nutlets to a snake’s head.
21. Parsley (Petroselinum crispum)
One of the world’s most widely used culinary herbs, parsley is botanically a biennial. In year one it produces the familiar aromatic leafy growth used in cooking. In year two it bolts, producing tall stems with yellow-green umbel flowers before dying. Most gardeners grow it as an annual, harvesting the leaves without allowing it to flower. It is native to the central Mediterranean and is cultivated globally on a large scale.
22. Carrot (Daucus carota subsp. sativus)
The cultivated carrot is one of the world’s most economically important biennial vegetables, almost always grown as an annual and harvested at the end of year one when the taproot is at its sweetest. Carrots are grown in over 100 countries, with global production exceeding 40 million tonnes per year. Left to their second year, they would produce tall, white-flowered umbels and woody, inedible roots.
23. White Campion (Silene latifolia)
White campion is a biennial or short-lived perennial of disturbed ground, roadsides, and field margins across Europe and Asia. It forms a leafy plant in year one and in year two produces white, five-petalled flowers that open in the evening and are pollinated by moths. The male and female flowers are on separate plants. It has naturalised widely in North America and is a common agricultural weed.
24. Clover Broom (Cytisus scoparius — some biennial forms)
Some forms of this leguminous shrub behave as biennials in particularly harsh or exposed environments, flowering in their second year before dying back. Better known biennial species in the broom family include certain Genista species. Broom-family plants fix nitrogen in the soil via root bacteria, making them important pioneer plants on poor or disturbed soils.
25. Hound’s Tongue (Cynoglossum officinale)
Hound’s tongue is a biennial native to dry, open habitats across Eurasia. In year one it forms a rosette of soft, grey-green, tongue-shaped leaves. In year two it produces branching clusters of small, dark red-purple flowers followed by flat nutlets covered in hooked bristles that adhere firmly to animal fur and clothing. It contains toxic pyrrolizidine alkaloids and was historically used with great caution in herbal medicine.
26. Scotch Thistle (Onopordum acanthium)
The Scotch thistle — widely regarded as the national emblem of Scotland — is a stately biennial that can reach 3 metres in its second year. In year one it forms a large rosette of deeply lobed, spiny, white-cottony leaves. In year two it produces branching stems topped with large purple flowerheads. Despite the name, it is native to southern and central Europe and central Asia, not Scotland specifically.
27. Yellow Toadflax (Linaria vulgaris)
While often behaving as a perennial via root sprouting, yellow toadflax frequently completes its life cycle as a biennial in its native European range. It produces a first-year rosette followed by upright stems bearing snapdragon-like yellow and orange flowers in year two. It has naturalized across North America, where it is considered an invasive weed of roadsides and disturbed areas.
28. Common Verbascum / Dark Mullein (Verbascum nigrum)
Dark mullein is a slender biennial mullein of dry grasslands, roadsides, and woodland edges in Europe and Asia. It forms a flat rosette in year one and in year two produces tall spikes of yellow flowers with purple-bearded stamens. It is more graceful than the common mullein, reaching around 1 metre. Its flowers attract a variety of bee species, particularly wool-carder bees.
29. Weld / Dyer’s Rocket (Reseda luteola)
Weld is a biennial native to Europe and the Mediterranean, historically one of the most important yellow dye plants in the world. Its first-year rosette gives way in year two to tall, narrow spikes of tiny greenish-yellow flowers. The whole plant contains luteolin, a flavonoid that produces a clear, fast yellow dye. It was used extensively in the textile industries of medieval Europe before synthetic dyes were developed.
30. Hemlock (Conium maculatum)
One of the most infamous of all biennial plants, hemlock is native to Europe and the Mediterranean and has naturalised almost worldwide. In year one it forms a ferny rosette; in year two it produces tall, hollow stems with distinctive purple blotches, topped with flat white umbels of flowers. All parts of the plant are deadly poisonous, containing coniine and other alkaloids. It was reportedly the poison used in the execution of the philosopher Socrates in 399 BC.
31. Parsley (Petroselinum crispum — Hamburg type)
Hamburg parsley is a root-type biennial variety grown primarily for its thick, parsnip-like taproot rather than its leaves. Popular in central Europe — particularly Germany, Poland, and the Netherlands — it forms an edible, ivory-coloured root in its first year with a flavour resembling a combination of parsley, celeriac, and parsnip. The roots are used in soups, stews, and roasted vegetable dishes.
32. Wild Angelica (Angelica sylvestris)
Wild angelica is a tall biennial of wet woodlands, riverbanks, and fens across Europe and Asia. In year one it establishes a rosette; in year two it produces hollow, purplish stems up to 2 metres tall, topped with large, dome-shaped umbels of white or pinkish flowers. The flowers are a major nectar source for a huge range of insects. It is closely related to garden angelica, used in herbal liqueurs and confectionery.
33. Meadow Clary (Salvia pratensis)
Meadow clary is a biennial or short-lived perennial sage native to dry, calcareous grasslands across Europe. In year two it produces striking spikes of deep violet-blue flowers with a unique pollination mechanism: visiting bees trigger a lever that deposits pollen on their backs. It has declined significantly in parts of northern Europe due to agricultural intensification and is now considered a grassland conservation indicator species.
34. Agrostemma / Corncockle (Agrostemma githago)
Once a common biennial weed of European cereal fields, corncockle has become rare due to modern seed-cleaning and herbicide use. It forms a slender, upright plant with narrow leaves and produces large, solitary pink-purple flowers with long, narrow sepals in year two. The seeds are mildly toxic. It is now widely grown in wildflower mixes as a conservation measure, and its decline is considered a significant loss to farmland biodiversity.
35. Bitter Dock (Rumex obtusifolius)
Bitter dock is a robust biennial or perennial of roadsides, pastures, and waste ground across Europe and Asia. In year one it forms a large rosette of broad, dark green leaves. In year two it produces tall, branching spikes of small green-brown flowers. While often regarded purely as a weed, dock leaves have a long folk tradition of soothing nettle stings, and the plant’s seeds are eaten by birds over winter.
36. Wild Basil (Clinopodium vulgare)
A delicate biennial or short-lived perennial of dry, calcareous grasslands and scrub in Europe and Asia, wild basil is unrelated to culinary basil despite its name. It forms small, rounded plants with softly hairy leaves and whorls of pale pink-purple tubular flowers in year two. It is a useful nectar plant for bumblebees and other pollinators on chalk and limestone grasslands.
37. Felwort / Autumn Gentian (Gentianella amarella)
Felwort is a small biennial gentian of chalk and limestone grasslands in Europe. It forms a tiny rosette in year one and in year two produces branching stems of small, four- or five-petalled dull purple flowers with distinctive fringed petal edges. It is a biodiversity indicator of ancient, unimproved grassland and has declined sharply in the UK and Western Europe due to habitat loss and agricultural change.
38. Night-Scented Stock (Matthiola longipetala)
Night-scented stock is a slender Mediterranean biennial with small, four-petalled flowers in shades of pink, white, and purple that release an intensely sweet fragrance after dark. In gardens it is typically treated as a hardy annual, but in its native habitat it behaves as a biennial. It is often sown with ten-week stocks (Matthiola incana) to extend the period of fragrance in the evening garden.
39. Borage (Borago officinalis)
Though often classified as a self-seeding annual, borage can behave as a biennial in certain climates, particularly in sheltered Mediterranean environments. It is native to the Mediterranean basin and produces star-shaped, brilliant blue flowers — one of the few truly blue edible flowers in cultivation. The flowers are used to garnish salads, cocktails, and desserts. The leaves have a mild cucumber flavour and are used in herbal preparations and cool summer drinks.
40. Queen Anne’s Lace (Daucus carota var. carota)
Queen Anne’s lace is the wild European form of the carrot, widely naturalised across North America and Asia. A true biennial, it forms a rosette and carrot-scented root in year one, then sends up tall, branching stems topped with flat, intricate white umbels in year two. The central floret is often deep purple-red, traditionally said to represent a drop of blood where Queen Anne pricked her finger while making lace. It is one of the most recognisable and widespread wildflowers of the temperate world.