Description
Garden cosmos belongs to the aster family and grows wild in Mexico, which is why it is often called the Mexican aster abroad.
It is an annual up to 1 metre tall that readily self-seeds. Its stems are upright and heavily branched, with doubly pinnate light green leaves resembling dill.
The flower heads are large, with relatively long, slightly protruding ray florets arranged in a ring. They appear in great numbers from July to October and attract many species of butterfly. The flowers come in a wide range of colours, from white and pink to violet and purple. Many varieties have been selected by flower type and colour. The fruits are elongated dark brown achenes.
Requirements
Cosmos is undemanding and resistant to diseases and pests.
Propagation
It is propagated by seed sown in a semi-warm cold frame in April. Plant out in the final position in May at 40 x 50 cm. Seeds can also be sown directly outdoors in mid-May; the plants will then flower later.
Care
Cosmos grows well in moderately fertile soil in a sunny position. It is undemanding but sensitive to frost. In gardens it is planted in large borders and in groups on lawns, and it is also suitable as a cut flower.