Cucumber (Cucumis sativus) — identification, habitat & look-alikes

Cucumbers are fast-growing annual vines grown in gardens across the U.S.; Spanish explorers brought them to the Americas in the 1490s. They climb with curly and bear yellow flowers. Most are grown as slicing cucumbers for salads or as short, bumpy pickling cucumbers.

Appearance

Growth form: An annual vine with spiraling tendrils and large leaves that shade the fruit.
Flowers: Yellow flowers. Male and female flowers grow on the same plant; the first 10–20 flowers are usually male and won't make fruit. Female flowers have a tiny cucumber behind the petals.
Fruit: Botanically a kind of berry, about 95% water. Pickling types are picked at 2–6 in (5–15 cm), slicers at 6–10 in (15–25 cm).

Look-alikes

Bur CucumberSicyos angulatus

Bur cucumber has small white flowers in mid to late summer and clusters of tiny fruits about 0.4 in (1 cm) long, covered in stiff spines. Garden cucumber has yellow flowers about 1 in (3 cm) across and long smooth or bumpy fruit.

Why they get mixed upA native vine whose seedlings look very much like cucumber seedlings.

Wild CucumberEchinocystis lobata

Wild cucumber has small white flowers in July and August, not yellow ones, and climbs high over shrubs and fences along fields and woods.

Why they get mixed upA native vine with 'cucumber' in its name whose seedlings resemble garden cucumber.

Where it lives

Typical habitats: Vegetable gardens
Farm fields
Greenhouses
Range: Native to South Asia, from India and Nepal to southern China and northern Thailand. It was domesticated in India from a wild form (Cucumis sativus var. hardwickii). In the U.S. it's a cultivated crop, not a wild plant.
Preferred conditions: Frost-tender. Plant outdoors after the last frost once the soil reaches about 70°F (21°C); seeds won't sprout in soil below 50°F (10°C).

Life cycle

Reproduction: Most seeded varieties need bees to move pollen to the female flowers, and commercial growers bring in honey bee hives at bloom. Some modern hybrids set fruit without pollination.

Growing it

Care: Most varieties are ready to pick 50–70 days after planting. Pick often while fruit is young to keep vines producing. Common pests include cucumber beetles, pickleworms, aphids, and squash vine borers.
Toxicity: Bitterness comes from natural compounds called cucurbitacins. It shows up more after big temperature swings and is strongest near the stem end and in the peel, so trimming that end and peeling helps.

Name and classification

Varieties and forms: Main U.S. groups: slicing cucumbers (long, smooth, thicker skin), pickling cucumbers (short, blocky, bumpy; small ones are called gherkins), and burpless or English cucumbers (long, nearly seedless, often greenhouse-grown).

Conservation

IUCN Red List: NENot EvaluatedNot yet assessed

Culture and stories

Culture and stories: The Roman emperor Tiberius reportedly ate cucumbers year-round; his gardeners grew them under frames glazed with a thin, clear mineral, probably mica.