How to Grow Agrostemma Plants in your Garden

Gardener's HQ Guide to Growing Corn-cockle

The common name for the Hardy annual Agrostemma is the Corn cockle.

It typically flowers in the summer.

Description of Agrostemma

Agrostemma are medium sizes plants that can grow to between 60 and 90 cm (2 to 3 feet) in height. Agrostemma has very small trumpet shaped dark pink flowers.

It is an ideal plant for growing in borders and cottage gardens.


Agrostemma Corn Cockle
Agrostemma githago photographs by Ospano and littleherelittlethere.

Information on Agrostemma and Commonly Grown Garden Species

The Agrostemma genus consists of just two species and is a member of the Caryophyllaceae family. This family contains 42 genera including Carnations (Dianthus), Campions (Silene) and sandworts (Stellaria). The genus originated in the Mediterranean region of Europe and is now widespread throughout the world.

Though gardeners often use this beautiful plant in cottage and meadow gardens it is considered a weed of wheat fields (The Plant is native to the UK, and the word Corn is used to describe wheat in England, Oats in Scotland, and Maize in the USA).

Some varieties of the two species of Agrostemma that are often grown in gardens include: Corn cockle (Agrostemma githago), varieties include Common, Milas, Milas Rose Queen, Purple Queen, Contessa Pale Pink, Narrow Corn Cockle (Agrostemma brachyloba) and Ocean pearl Cockle.

Quick Agrostemma Growing and Care Guide

Common Names: Corncockle: Common, Narrow, Milas, Milas Rose Queen, Purple Queen, Contessa Pale Pink, Ocean pearl.
Life Cycle: Hardy annual.
Height: 20 to 36 inches (50 to 90 cm).
Native: Mediterranean, Europe.

Growing Region: Zones 1 to 10.
Flowers: Mid-spring through to Mid-summer.
Flower Details: Pink, purple. Cup/vase-shaped. Contained within ribbed sepal tube.
Foliage: Pale green. Lanceolate. Opposite.

Sow Outside: 1/8 inch (3 mm). Following the last frost. Spacing 9 to 12 inches (25 to 30 cm).
Sow Inside: Germination time: two to three weeks. Temperature 55 to 65°F (13 to 18°C). Seven or eight weeks in advance. Transplant outdoors following the last frost or in autumn (in warm climates).
Requirements: Full sunlight or partial shade. Good drainage. Loam. Deadhead.

How to Grow Agrostemma

It is best to sow Corncockle at a depth of 1/4 cm, with a spacing of 22 to 30 cm, in early spring after the last frost as occurred. Agrostemma prefers to grow in full sunlight. The soil should ideally be a rich loam, though the plant is capable of surviving in most soils. Agrostemma requires between two or three weeks for germination to occur.

If initiating growth indoors then it is best to sow at a temperature of thirteen to eighteen degrees Centigrade seven or eight weeks before planting outdoors in the early spring or late autumn in milder climates.

Taking care of corn cockle in the garden

Corn cockle is easy to take care of, it requires watering in dry spells during the summer, and the removal of dead flower heads to stop seed set, and the plant from becoming a weed. The seeds of the plant are poisonous so handle with care.

I hope that you enjoyed this guide on Agrostemma. You may also enjoy the following garden growing guides: How to grow Arenaria and Silene plants.