Description: H. annuus is an annual species of the genus Helianthus, the most common variety of the sunflowers. It originated in the Americas and was introduced to Europe in the 16th century. It is grown primarily for ornamental purposes as well as for its seeds which are used as a human and live stock feed, as well as in the production of edible oils and biofuels.
A young seedling emerging.
Size: H. annuus is a steeply growing plants under favourable conditions, usually reaching heights of around 2 - 3.5 meters. Some plants have reached heights of 6 meters and beyond.
Conditions: This plant enjoys warm and moist soils full of organic matter and full sun exposure. If the soil is too dry, the growth will be stunted.
A young plant damaged by transplantation and poor soil conditions.
Propagation: H. annuus spreads by the seeds it produces in its flower-head. They mature by the end of the plants life and are picked by birds which spread it via their droppings.
A maturing plant opening its flower-head.
When to plant: Traditionally grown as a summer crop, planted in spring once the soil has warmed up, this species is also known to survive colder conditions if enough sun is available.