Glaucium spp.

horned poppy

Papaveraceae

Europe, the Mediterranean, North Africa, and western and central Asia

Attracts Pollinators Deer Resistant Drought Tolerant

SunFull Sun

WaterLow · drought-tolerant

HardinessZones 6–9

Overview

Glaucium spp. is a genus of about 25 annual, biennial, and short-lived perennial plants in the poppy family, Papaveraceae, native to Europe, the Mediterranean, North Africa, and western and central Asia. The plants are recognized by their glaucous, blue-grey foliage: deeply lobed, wavy-edged leaves that form a basal rosette in the first year and clothe branching flower stems 1-3 feet (30-90 cm) tall in the second. From late spring through summer they bear solitary cup-shaped poppy flowers 2-3 inches (5-8 cm) across in yellow, orange, or red, each lasting a day or two and followed in succession. The defining feature is the seed pod, a slender curved capsule 6-12 inches (15-30 cm) long that gives the group the name horned poppy. G. flavum, the yellow horned poppy, grows on coastal shingle and is biennial, while G. corniculatum bears red or orange flowers and is annual. All parts contain toxic isoquinoline alkaloids and are poisonous if eaten. Plants self-seed freely and can naturalize on open ground. The blue-grey foliage and long horned pods persist after the brief flowers fade.

Native Range

Glaucium spp. is native to Europe, the Mediterranean region, North Africa, and western and central Asia. G. flavum grows on coastal shingle and sand around the Atlantic and Mediterranean coasts, while other species occupy dry, open, disturbed ground inland. Several species have naturalized beyond their native range.

Suggested Uses

Grown in coastal, gravel, and dry gardens and in sunny borders for the blue-grey foliage and poppy flowers. The plants self-sow into paving cracks, shingle, and open ground where conditions are lean. The long horned pods are cut for dried arrangements.

How to Identify

Look for a rosette or branching plant with glaucous, blue-grey, deeply lobed and wavy-edged leaves, bearing cup-shaped poppy flowers in yellow, orange, or red. The unmistakable sign is the seed pod, a narrow curved capsule 6-12 inches (15-30 cm) long. The blue-grey foliage and long horned pods together identify Glaucium spp..

Appearance

Size & Dimensions

Height1' - 3'

Width/Spread1' - 2'

Colors

Flower Colors

Foliage Colors

Bloom Information

Bloom Period

~10 weeks

Summer

Flowering runs from late spring through summer, generally June to September depending on species and climate. Each cup-shaped flower lasts only a day or two, but plants open a steady succession over many weeks. The long horned seed pods develop quickly after each bloom.

Detailed Descriptions

Flower Description

yellow, orange, red

Foliage Description

blue-grey

Growing Conditions

Sun Requirements

SunFull Sun

Requires 6-12 hours of direct sunlight daily

• Full Sun: 6+ hours of direct sunlight

• Partial Shade: 3-6 hours of direct sunlight

• Full Shade: Less than 3 hours of direct sunlight

Soil Requirements

pH Range6.0 - 8.0(Neutral)

357912

Soil Types

sand rocky

Drainagewell drained

Water & Climate

Water Needs

Low

Frost Tolerance

hardy

Time to Maturity

1-2 years

Drought Tolerance

Drought tolerant when established

Care & Maintenance

Care Guide

Plants grow in full sun on poor, sandy, gravelly, free-draining soils and tolerate salt, drought, and coastal exposure. They resent rich soil and winter wet, which cause soft growth and rot, and the long taproot makes established plants difficult to move. G. flavum is grown as a biennial, flowering and seeding in its second year, while annual species complete the cycle in one season. Plants are usually raised from seed sown where they are to grow, since they transplant poorly. Hardiness covers roughly USDA zones 6 to 9 for the hardier species. All parts are toxic if eaten, and the sap can irritate skin.

Pruning

Removing spent flower stems prolongs bloom and limits the heavy self-seeding, though some pods are left if seedlings are wanted. Whole plants are cleared after they die back, with biennials and annuals pulled once seed has set. The brittle, taprooted stems are cut rather than pulled near neighbors.