Agrostemma githago

Sowing and care guidance

Agrostemma githago seeds perform best when direct sown where they are to flower, as they dislike root disturbance. Sow after the last frost, or in mild climates in autumn, onto a fine, well-drained, not overly rich soil in full sun. Keep the seedbed just moist until germination, then water sparingly; lean conditions encourage sturdier growth. Thin promptly to provide airflow, following packet spacing guidance for this medium-tall annual, and consider discreet staking in windy sites. Deadhead to extend the display, or allow a few heads to ripen if self-sowing is desired. All parts are considered toxic if ingested; place thoughtfully and avoid contamination of edible areas.

• Direct sow after last frost; in mild climates, autumn sowing may succeed; avoid transplanting to prevent root disturbance.
• Choose full sun and well-drained, not overly rich soil; minimal feeding keeps plants upright.
• Thin seedlings early to maintain airflow; follow packet spacing guidance; water to establish, then moderately.
• Medium-tall habit; provide windbreak or light staking in exposed sites.
• Ornamental: Graceful, papery blooms suit naturalistic borders and cut-flower displays.
• Pollinator friendly: Simple, open flowers are accessible to visiting insects.

How do I grow Agrostemma githago (corncockle) from seed?

Agrostemma githago is best grown by direct sowing, as it dislikes root disturbance. Sow onto a raked, weed-free, well-drained seedbed after the last frost when soil is workable; in mild climates, autumn sowing may be possible for earlier bloom. Cover lightly (about 3–5 mm), keep evenly moist until germination, and avoid overwatering. Seedlings establish quickly; thin rather than transplant to reduce shock. Growth is most floriferous in lean conditions, so avoid rich feeds. Successional sowings a few weeks apart extend the display, and light deadheading can prolong flowering unless seed is being saved.

What soil and sunlight are best for corncockle plants?

Corncockle thrives in full sun and well-drained soil that is not overly rich. It performs well in poor to moderately fertile ground, where stems stay sturdier and flowering is generous. On heavy or compacted sites, improve drainage by incorporating grit or coarse organic material rather than high-nutrient composts. Water to establish and during prolonged dry spells, but allow the surface to dry between waterings; persistent waterlogging can cause weak growth. In borders or meadow-style areas, keep surrounding vegetation in check so plants receive unshaded light throughout the day.

How far apart should Agrostemma githago be spaced, and does it need support?

Space plants to allow good airflow, typically thinning seedlings to around 20–30 cm apart. This reduces crowding, encourages upright growth, and helps limit foliar issues in damp spells. Agrostemma is medium-tall and can sway in wind; in exposed sites, discreet support such as low twine grids or a few canes can prevent lodging without spoiling the natural look. Avoid dense clumps that shade each other, and remove competing weeds early. Follow packet guidance for the specific strain’s vigor, adjusting spacing slightly in lean or especially fertile soils.

Is corncockle poisonous?

Yes. Corncockle is an ornamental plant and is poisonous if ingested, with the seeds considered the most toxic part. Avoid growing it where seed or plant material could mix with edible crops, and keep it out of areas used for animal forage. Handle mature seed heads with care and wash hands after large-scale handling or seed processing. Dispose of unwanted seed responsibly and avoid adding ripe seed heads to compost that will later be used around edibles.

Can corncockle be used as a cut flower and mixed into wildflower plantings?

Corncockle is valued as a cut flower for its airy stems and satiny blooms; stems hold well if cut when the first flower opens and the next buds show color, then conditioned in clean water. In meadow-style or wildflower plantings, it mixes attractively with other annuals that enjoy lean, sunny conditions, adding height and movement while supporting pollinators. It may self-seed in open soil; deadhead if you wish to limit spread, or allow some seed to ripen for a more naturalized effect the following season.

How do I save seed from Agrostemma githago?

Allow flowers to fade and the seed pods to dry on the plant until they turn brown and papery. Collect heads before they shatter, then dry further under cover and gently break them open. Clean by sieving and winnowing to remove chaff, and ensure seeds are fully dry before storage. Label and store in a cool, dry place. If maintaining specific flower colors or forms, grow only one strain at a time or separate plantings, as open-pollinated plants can cross. Saved seed typically germinates well the following season.

This site provides general cultivation guidance intended for a range of conditions. Local microclimate, soil type, drainage, and exposure can influence timing and results, including recommendations such as sowing after the last frost or when soil is workable. Precise directions are available on individual product pages, including source details and specific handling, sowing, and spacing information relevant to each item.

Cultivation Guide for Agrostemma (Corncockle)

Agrostemma githago, often called corncockle, offers graceful, papery blooms on slender, branching stems that fit well in naturalistic borders and cutting patches. For best results, direct sow where plants will flower, as the species dislikes root disturbance. Sow after the last frost when the soil is workable; in mild climates, autumn sowing may be possible for an earlier start. Seeds benefit from light to germinate—press into a fine, free-draining surface and barely cover. Full sun and lean to moderately fertile soil encourage sturdy growth; overly rich conditions can cause flopping. Space 20–30 cm apart and consider discreet support in windy sites. Water consistently during establishment, then allow the soil to dry slightly between waterings. Deadhead to extend the display, or leave a few pods to mature if gentle self-seeding is welcome. Plants typically reach 60–90 cm and pair well with airy annuals and grasses, adding movement and a classic cottage feel.